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1. BASIC SCIENCE

1.1 VAGAL STIMULATION DOES NOT AFFECT THE SPECTRUM PATTERN OF ATRIAL ELECTROGRAM

*S. Oh, *E.K. Choi, *J.J. Kwak, *Y.S. Choi *Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea

Introduction: As an adjunctive method to conventional ablation of atrial fibrillation (AF), ablation of sites showing high-frequency spectral component (HFC) during sinus rhythm, known as AF nest, has been introduced. Locations of some HFC sites are similar with those of ganglionated plexi. However, it has not been elucidated whether vagal stimulation can alter the spectrum pattern of atrial electrogram.

Methods: Five anaesthetized open-chest dogs were evaluated. Atrial electrograms during sinus rhythm were obtained epicardially from the right atrium (appendage, crista terminalis, free wall, and the sinus node), the left atrium (appendage, free wall, and right and left pulmonary vein antrum), and the coronary sinus. Vagal stimulation was performed to double the sinus cycle length with 20 Hz, 0.2 ms, 4–10 V at both cervical vagus nerves. Dominant frequency and area of HFC were measured in power spectrum of each electrogram.

Results: Electrograms obtained from the sinus node and crista terminalis of all dogs, left atrial appendage (3/5 dogs), and the coronary sinus (3/5 dogs) had HFC at basal state and during vagal stimulation. However, there were no significant spectrum differences between basal state and during vagal stimulation.

Conclusions: HFC of atrial electrogram during sinus rhythm seemed to be mostly resulted from the inhomogeneity of underlying structure rather than autonomic tone.

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1.2 EFFECTS OF VAGAL STIMULATION ON ACTION POTENTIAL DURATION RESTITUTION IN THE ATRIUM

*S. Oh, **Y. Zhang, **A. Natale, **T.N. Mazgalev *Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea **Center for Atrial Fibrillation, Cleveland Clinic, Cleveland, Ohio, USA

Introduction: Action potential duration restitution (APDR) is governed by multiple ion-channel kinetics, and the function of these ion channels is modulated by the autonomic nervous system. Therefore, vagal activation may affect APDR, but this hypothesis has not been evaluated. This study was designed to demonstrate the effects of vagal stimulation on the atrial electrical restitution property.

Methods and Results: Seven mongrel dogs were studied. Vagal stimulation (VS) was applied at the right cervical vagus nerve at intensities to decrease the sinus rate by approximately 50%. Typical parameters for the cervical VS trains were frequencies of 20 Hz at pulse amplitude of 1.2 ± 1.1 mA (0.5–3.5) and a pulse width of 0.2 ms. Electrocardiographic and atrial electrograms were recorded during programmed pacing and monophasic action potential recordings were performed on the epicardial surface of the appendages (RAA, LAA) and free walls (RAFW, LAFW) of both atria. The APDR curves were constructed by plotting the APD90 versus the preceding diastolic interval (DI). The major results are illustrated in the Figure. VS increased the steepness of the maximum slope (left), flattened the slope at DI > 100 ms (middle), and significantly increased the spatial dispersion of APDR curve in atrial compartments (right).

Conclusions: The reported effects might be one of the arrhythmogenic mechanisms of VS in the atrium. Changes in APDR could provide rationale for vagal denervation in AF treatment.

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1.3 CHANGES OF AUTONOMIC TONE DURING SUSTAINED VENTRICULAR TACHYCARDIA IN A CANINE MODEL

*O. Paz, *M. Swissa, *P.S. Chen *Cedars-Sinai Medical Center and David Geffen School of Medicine, UCLA, Los Angeles, California, USA

Introduction: There is growing evidence that autonomic imbalance plays an important role in the generation of ventricular arrhythmias. Recognition of specific factors contributing to VT initiation can lead to a better therapeutic intervention. We studied the relationship between the sympathetic nerve activity and ventricular tachycardia (VT) episodes in a canine model.

Methods: Five dogs underwent surgery to create complete AV block, anterior myocardial infarction (MI) and implantation of an osmotic minipump for nerve growth factor (NGF) infusion over a five week period. We also implanted a data science international (DSI) transmitter to constantly monitor electrocardiograms and bipolar atrial and ventricular electrograms for a period of up to three months. Because these animals have intacted sinus node, A-A interval was used as an estimate of the autonomic tone. We manually analyzed all DSI recordings for sustained monomorphic VT (S-MM-VT) episodes. The A-A intervals were determined prior to, during and after the termination of VT. VT that persisted for at least 30 beats defined S-MM-VT.

Results: A total of 17 S-MM-VT episodes were found. All VT episodes were preceded by atrial rate acceleration and could be recognized accurately by plotting a graph of atrial rate versus time in a one-hour window prior to the onset of VT. The mean A-A intervals immediately before and after VT were 338 ± 82 ms and 800 ± 844 ms, respectively (p = 0.05). During the sustained VT episodes the atrial rate slowed significantly (p<0.05). The magnitude of atrial rate slowly correlated positively to the VT duration. The mean maximal A-A intervals during VT were 966 ms in the 30–40 beats VT group, 1895 ms in the 41–50 beats VT group and 11867 ms in the longer VTs. The maximal pause (39 seconds) in sinus activity was found during a 66 second (185 beats) VT episode.

Conclusions: Atrial rate acceleration preceded each S-MM-VT episode and significant atrial rate slowly occurred invariably during the sustained VT episodes. The data suggests that sympathetic surge plays a role in initiating VT and the increased vagal tone may be responsible for the termination of sustained VT.

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1.4 DEVELOPMENT OF PULMONARY ARTERIAL HYPERTENSION IN RATS IS ASSOCIATED WITH ARRHYTHMIA PROPENSITY

*I. Henkens, *K. Mouchaers, *H. Vliegen, *W. Van der Laarse, *C. Swenne *Leiden University Medical Centre, Dept. of Cardiology, Leiden, the Netherlands VU University Medical Centre, Dept. of Pulmonology, Amsterdam, the Netherlands

Introduction: Sudden cardiac death in pulmonary arterial hypertension (PAH) may be understood through evaluation of developmental changes in myocardial electrical properties.

Methods: PAH was induced in 15 male Wistar rats by injection of 40 mg/kg of monocrotaline (MCT). Saline-injected rats served as controls (n = 6). One minute ECGs were recorded with a modified Frank lead system, at baseline, and 25 days after MCT/saline injection. RV systolic pressure was measured invasively before sacrifice on day 25.

Results: Baseline ECGs of MCT and control rats were similar. On day 25 RV systolic pressure was normal in controls (<25 mmHg), and elevated (>50 mmHg) in MCT rats. QRS duration, QRS amplitude and T-wave area had not changed in either group. Compared to controls, MCT rats showed important changes in spatial ventricular gradient magnitude (−31 ± 17 mV*ms vs. 0.4 ± 17 mV*ms, P < 0.001), and QRS-T spatial angle (115 ± 56° vs. −13 ± 34°, P < 0.001), signifying action potential duration heterogeneity and repolarization sequence alterations.

Conclusions: Increased arrhythmia propensity in pulmonary arterial hypertension may originate from alterations in action potential duration heterogeneity and repolarization sequence.

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1.5 EXPLORATION OF THE MECHANISMS OF PACING POSTCONDITIONING

*F.W. Prinzen, *F.A. Babiker, *,**W.Y. Vanagt, ***T.C. Baynham, ***J. Spinelli, *,**T. Delhaas *Departments of Physiology, Maastricht, the Netherlands **Pediatrics Division of Pediatric Cardiology, Cardiovascular Research Institute, Maastricht, the Netherlands ***Boston Scientific, St. Paul, USA

Introduction: We previously showed that intermittent ventricular pacing during early reperfusion induces cardioprotection (pacing postconditioning, PacePost). We tested whether PacePost can be explained by gradual reperfusion and which signaling pathways are involved in PacePost.

Methods: Isolated ejecting rabbit hearts underwent 30-minute coronary occlusion and 2-hour reperfusion. PacePost consisted of 10 × 30-sec ventricular pacing during early reperfusion. We studied: Controls (n = 5), PacePost (n = 4) and PacePost + selective blockers of mitochondrial K+ATP channel (5HD, n = 5), PKC (Chelerythrine, n = 3) and PI3K (Wortmannin, n = 4). In 5 other control and 5 PacePost hearts, myocardial blood flow (MBF, microspheres) was measured during early reperfusion.

Results: Infarct size, normalized to area at risk, was significantly smaller in PacePost (27.9 ± 1%; mean ± SD) than in Control (48.0 ± 3%). Chelerythrine, 5HD, and Wortmannin completely abrogated the protection provided by PacePost (infarct sizes: 52 ± 2%, 48.9 ± 1% and 51 ± 3%, respectively). During early reperfusion, MBF in the postischemic myocardium was not different between PacePost and Control (8.8 ± 5.3 vs. 10.0 ± 3.5 ml/min/g, respectively; p > 0.5).

Conclusions: PacePost is mediated by well-known protection pathways, and is not due to gradual reperfusion. PacePost can, therefore, be regarded as true postconditioning.

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2. CARDIAC ARRHYTHMIAS: PEDIATRIC ASPECTS

2.1 EPIDEMIOLOGY AND OUTCOME OF TACHYARRHYTHMIAS IN CHILDREN

*M. Massin, *G. Rondia, *A. Benatar *Divisions of Pediatric Cardiology, Queen Fabiola Children's University Hospital (ULB) and Academic Hospital (VUB), Brussels, Belgium

Introduction and Methods: Our aim is to describe the epidemiology, clinical presentation, diagnostic methods, treatment and outcome of a long series of children with clinically relevant arrhythmias over a period of 10 years.

Results: Thirty-eight neonates and 162 children with supra-ventricular arrhythmias and 39 with ventricular arrhythmias were identified, 60% of whom were male. Frequent initial symptoms were palpitations (n = 67) and syncope (n = 47) in older children, and monitoring of other diseases (n = 60) and heart failure (n = 45) in younger ones. The ECG was pathological in 162 cases and contributive (long QT, delta wave) in 60. Holter recording and exercise ECG were positive in 129 and 10 cases. Recurrence was noted under or after initial therapy in 71 cases, mostly in those diagnosed beyond infancy. In the long-term, 161 had no recurrence without treatment (34 required catheter ablation), 68 were treated and 10 died.

Conclusions: The clinical spectrum of pediatric arrhythmias is diverse. Younger children with supra-ventricular arrhythmias respond to anti-arrhythmic therapy and have a high incidence of resolution. In other cases, the arrhythmias are unlikely to be resolved spontaneously, and long-term medications or catheter ablation are necessary.

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2.2 SINUS NODE FUNCTION IN YOUNG ADULTS WITH D-TRANSPOSITION OF GREAT ARTERIES, AFTER CORRECTION BY SENNING ATRIAL SWITCH

*A.Z. Pietrucha, *M. Węgrzynowska, **B.J. Pietrucha, *D. Mroczek-Czernecka, **A. Rudziński, *W. Piwowarska *Coronary Disease Department, Institute of Cardiology, Medical School of Jagiellonian University, John Paul II Hospital, Cracow, Poland **Children Cardiology Department, Children University Hospital, Medical School of Jagiellonian University, Cracow, Poland

Introduction: Purpose of this study was the evaluation of sinus node long-term automaticity in asymptomatic young adults after reparation of d-transposition of great arteries repaired by Senning atrial switch. We observed 12 pts (1 female, 11 male) aged 18–21 yrs with d-transposition of great arteries after correction through Senning atrial switch, with electrocardiographic signs of sinus node dysfunction (SNA) and no syncope and/or symptomatic bradycardia history. All pts had episodic or sustained bradycardia in 12-lead and/or 24-hour ECG, 5 pts had an escape nodal rhythm, 2 had registered asymptomatic tachycardia-bradycardia syndrome. There were no RR pauses longer than 2.5 s.

Methods: All pts underwent transoesophageal atrial stimulation (RAS) to evaluate extrinsic and intrinsic sinus node recovery times (SNRT), and corrected sinus node recovery times (CNRT), sino-atrial conduction time (SACT) and atrial refractory period (ERP-A). Pharmacological blockade (PHB) of sinus node was done with iv propranolol and atropine administration and intrinsic heart rate was assessed. SNRT > 1500 ms and CNRT > 525 ms were assumed as abnormal.

Results: Prolongation of extrinsic SNRT and/or CNRT with normalization after pharmacological blockade (functional SND) was observed in 8 pts (66.6%). The remaining patients presented normal sinus node recovery time values. All patients findings decreased intrinsic heart rate. Measured values are reported in Table 1.

Conclusions:

  • I. 
    Electrophysiological parameters of sinus node automaticity might fall within normal range regardless of electrocardiographic signs of sinus node dysfunction in young adults with transposition of great arteries corrected through Senning atrial switch.
Table 1. 
 HRSNRTCNRTSACTERP-A
extrinsic64.71582.4698.7128.5280.0
intrinsic76.71113.2364.2119.3250.0
  • II. 
    Both electrocardiographic monitoring and reduced intrinsic heart rate seem to be more useful than sinus node recovery time evaluation in assessing sinus node dysfunction in this group of patients.

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2.3 PACING IN PEDIATRIC PATIENTS WITH A NEW LEAD SYSTEM

*F. Cantù, **F. Gabbarini, *P. De Filippo, ***A. Della Scala, ***T. Marotta, *A. Borghi *Ospedali Riuniti di Bergamo, Bergamo, Italy **Infant Hospital Regina Margherita, Turin, Italy ***Medtronic Italy

Introduction: Permanent pacing in pediatric patients poses certain special problems related mainly to size, growth and, in congenital heart disease, complex anatomy. The Select Secure is a new pacing system based on a 4.1-Fr, active fixation, strong lead (3830, Medtronic) that may prove useful in this population.

Methods: Thirteen pediatric patients (mean age 10 ± 4, 3–15 years, six male) were implanted with single (five) or dual (eight) chamber pacemaker. Underlying diseases were congenital heart malformation (nine), cardiomyopathy (three), heart transplantion (one) and complete AV block.

Results: The 3830 lead was implanted successfully in all patients in the targeted chamber/s. Atrial sensing and threshold were 3.5 ± 2.9 mV and 0.4 ± 0.1 V at 0.5 ms at implant and 3.6 ± 2.4 mV and 0.5 ± 0.1 V at 0.5 ms at follow-up (10 ± 7 months). Ventricular sensing and threshold were 13 ± 4 mV and 0.7 ± 0.2 V at 0.5 ms at implant and 13 ± 9 mV and 0.8 ± 0.2 V at 0.5 ms at follow-up. There are no statistically significant differences. No adverse events were reported in the FU.

Conclusions: Select Secure is a promising system for permanent pacing in pediatric patients.

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2.4 CHRONIC ALTERNATE SITE PACING PERFORMANCE OF A NEW CATHETER-DELIVERED LEAD IN YOUNG PATIENTS WITH CONGENITAL HEART

*P. Karpawich, *K. Zelin *Pediatric Cardiology, Children's Hospital of Michigan, Wayne State University School of Medicine, Detroit, USA

Introduction: Alternate site pacing (ASP) can optimize paced myocardial functions, but it is difficult in patients (pts) with congenital heart defects (CHD). This report presents chronic ASP performance of a new 4.1 Fr diameter, catheter-delivered lead (Model 3830, Medtronic, Inc), in its initial use in CHD.

Methods: A total of 34 pts, aged between 5 and 48 yrs (median 18), received 52 leads (25 atrial; 27 ventricular) and examined from 1–18 months (median 10). CHD: D-transposition (TGA)/Mustard, ASD, VSD, LTGA/VSD, single ventricle/Fontan, aortic stenosis, congenital AV block, long QT, and sick sinus. DTGA pts included 6 baffle devices. ASP sites were determined by dP/dt/TDI.

Results: Best ASP sites: high lateral or septal right atrium (n = 15), RV septum (n = 20): in DTGA pts, high left atrium (n = 10) and LV septum (n = 7). ASP sites were achieved with minimal fluoroscopy from 0.6–9 minutes (median 2). There were no complications. Follow up showed excellent chronic lead stability (Table).

Conclusions: ASP in CHD is challenging. The catheter-delivered 3830 lead facilitates implant with minimal use of fluoroscopy, and ensures stable chronic thresholds in spite of various CHD anatomies and associated implanted vascular devices.

 Lead Performance (mean ± sem)
R Wave (mV)P Wave (mV)Thr 0.5 ms (V)Imp (Ω)
Implant12.2 ± 1.53.9 ± 0.60.7 ± .05943 ± 40
F/U11.2 ± 1.53.6 ± 1.90.4 ± .05644 ± 30
p ValueNSNSNSNS

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2.5 CARDIAC RESYNCHRONIZATION THERAPY IN YOUNG ADULTS WITH CONGENITAL HEART DISEASE AND HEART FAILURE: A BRIDGE TO TRANSPLANT

*P. Gupta, **P. Karpawich *Children's Hospital of Michigan, Detroit, USA **Wayne State University, Michigan, Detroit, USA

Introduction: Cardiac resynchronization therapy (CRT) may benefit adult patients (pts) with heart failure (CHF). There is limited data on CRT in adult congenital heart disease (ACHD) and CHF. Heart transplant (HT) is not always an option.

Methods: From 1999–2005, four ACHD pts, 17–28 years (median 21.5) underwent CRT for end-stage CHF (NYHA class III-IV) instead of HT. CHD: AV canal, L-TGA/VSD/pulmonary atresia, congenital AV block. CRT pacing was optimized based on cardiac catheterization hemodynamic data.

Results: (Table) All pts were followed for one to seven years (mean four) and demonstrated clinical improvement. Hemodynamics and ECHO variables improved from 20–46% of pre-CRT values. All pts were removed from HT consideration: one pt expired following valve surgery, one pt remained in NYHA class I for seven years and is now relisted for HT due to a decline in functional status, and two other pts remain in NYHA class I.

Table 2. 
 Parameters (mean ± SEM)
dP/dt (mmHg-sec)°LVEDP (mmHg)§QRS duration (msec)Ejection fraction (%)NYHA ClassO2 consumption (%predicted)"
  1. °Change in pressure with unit change in time.

  2. §Left ventricular end diastolic pressure; "Exercise stress test.

  3. p < .05 compared to baseline.

Baseline (prior to CRT)493 ± 114.518.3 ± 2.5197.5 ± 14.4 30 ± 8III-IV60.7 ± 20.2
Acute (with CRT)672 ± 92.514.3 ± 6.7 150 ± 10.836.7 ± 7.8 
Chronic (on follow up)616 ± 72  19 ± 1153.3 ± 12 44 ± 8.5I73.5 ± 31.5

Conclusions: These pts provide long-term information about CRT as a bridge to HT for ACHD pts with end-stage CHF. Optimization of lead implant, based on hemodynamic criteria, may suggest which pts will benefit from chronic CRT.

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2.6 COMBINED INTERVENTIONAL PROCEDURES IN PEDIATRIC PATIENTS WITH ARRHYTHMIAS

*S. Termosesov, *L. Kokov, *R. Garipov, *I. Ilich *Moscow Research Institute of Paediatrics and Pediatric Surgery, Moscow, Russia

Introduction: A combination of cardiac pathology is not rare in children with arrhythmias. New technologies allow for the simultaneous use of interventional pacemakers to correct all abnormalities.

Methods: The aim of this study is to report an experience of a group of 25 children with multiple cardiac alterations (16 boys, mean age 15.5 years). Patients (pts) were divided into: group I – six pts (24%) with atrial-septal defects or PDA combined with arrhythmias, group II – 10 pts (40%) with a combination of different types of tachy-arrhythmias, and group III – nine pts (36%) with a combination of tachy- and brady-arrhythmias.

Results: In group I 5 pts underwent atrial-septal closure, and 1 pt PDA closure simultaneously with catheter ablation RFCA of different arrhythmias. No recanalization was observed during follow-up up to 48 months later. In group II 9 pts underwent RFCA of different tachy-arrhythmias (WPW, AVNRT, focal AT and VT), and 1 pt RFCA + ICD implantation. In group III 9 pts underwent RFCA + PM implantation. The efficacy of RFCA was 100%, with neither recurrences nor complications.

Conclusions: Arrhythmias associated with cardiac abnormalities with appropriate endovascular correction indicate simultaneous interventional procedures resulting in good acute and long-term effects.

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3. SUPRAVENTRICULAR ARRHYTHMIAS: CLINICAL AND ABLATION ISSUES

3.1 THE COSTS OF ATRIAL TACHYARRHYTHMIAS – 1 YEAR FOLLOW-UP OF EPICARDIA STUDY

*E. Occhetta, **P. Diotallevi, *L. Venegoni, *L. Plebani, **A. Ravazzi, *P. Marino *Ospedale Maggiore della Carità, Novara, Italy **Ospedale SS. Antonio e Biagio e Cesare Arrigi, Alessandria, Italy

Introduction: Atrial Tachy-arrhythmias (AT) represents a collective economic burden. Italian cost data with reference to AT are lacking.

Methods: EPICARDIA study was a prospective evaluation of all Emergency Room (ER) admitted patients with AT diagnosis in four hospitals. The sample enrolled in two hospitals (Novara and Alessandria) has been retrospectively investigated on healthcare costs (visits, drugs, diagnostic tests, hospitalizations and ER access) one year after the end of the enrollment.

Results: Eighty-six patients were studied (mean age: 69.2 ± 12.31; 50% male). Half of them had a recurrence of AT and 31.8% were hospitalized. Of the 86 patients, 54 (62.8%) required at least one GP visit, 30 (34.9%) required at least one specialist visit, 73 (84.9%) required drug therapy, 60 (69.8%) required at least one diagnostic test and 25 (29,1%) required a cardiac procedure. The average annual total cost per patient was € 2,535 from the Regional Health Care System perspective.

Conclusions: AT absorbs a relevant amount of National Health Care System resources and requires attention in the priority setting process.

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3.2 SUPRAVENTRICULAR ARRHYTHMIAS IN THE METABOLIC SYNDROME: HISPANIC POPULATION

*P. I. Altieri, *N. Escobales, *M.J. Crespo, *Y. Figueroa, *J. Gil de la Madrid *Departments of Medicine and Physiology, University of Puerto Rico-School of Medicine and the Cardiovascular Center, San Juan Puerto Rico, USA

Introduction and Methods: We analyzed 173 patients admitted to the Heart Center with the metabolic syndrome (MS). Fifty-seven were male and 43 female. Of these patients, 97% were diabetic type II and 3% were diabetic type I. Mean body mass was 30 Kg/m2. The lipid profile of the group evaluated was normal. No significant coronary disease or strokes were detected.

Results and Conclusions: The ejection fraction (EF) was subnormal when compared to our control group (50 ± 8 vs. 62 ± 10%, P < 0.001). The end-systolic dimension of the left atrium in the MS group was increased (46 ± 10 mm vs. 40 ± 8 mm, P < 0.005). No ventricular tachycardias were detected, while a higher incidence of atrial fibrillation was found in the MS group (12% vs. 5.9%, P < 0.001). The mechanisms inducing arrhythmias will be discussed with particular emphasis on fat infiltration at the right atrium and sinus node. In addition, the role of remodeling atrial chambers and left ventricular function on supraventricular arrhythmias will be discussed.

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3.3 ABLATION OF SUPRAVENTRICULAR TACHYCARDIA IN THE ELDERLY: RESULTS AND LONG-TERM FOLLOW UP OF 165 PATIENTS

*V. Carinci, *G. Barbato, *F. Pergolini, *G. Di Pasquale *Cardiology Unit, Maggiore Hospital, Bologna, Italy

Introduction: Treating elderly patients (>75 years) with catheter ablation can be challenging because of prevalence of underlying cardiopathy and comorbidity.

Methods: Between January 1997 and December 2006 we treated 165 patients (93 men), mean age 79 ± 3.

Table 3. 
 PtsProcedure Success
AV junctional ablation45 (27%)95%
nodal re-entry tachycardia39 (24%)100%
atrial ectopic tachycardia16 (9.7%)87.5%
typical flutter54 (33%)96.3%
atypical flutter9 (5.4%)78%
AV pathways2 (1.2%)100%

In 14 patients the procedure required transeptal puncture. Acute complications were: 2 AV block (1.1%), 1 TIA (0.5%), 1 pericardial effusion (0.5%).

Results: During a mean follow up of 4.3 years we observed new onset of atrial fibrillation in 22 patients (13.3%) and recurrences in 10 cases (6%). In 10 patients a new arrhythmia was documented and treated. No late complications were documented.

Conclusions: Comparing the acute results and follow up of patients >75 years old with the younger population treated in our centre (1135 patients), we did not find any significant difference. Treating arrhythmias with catheter ablation in the elderly appears to be safe and effective.

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3.4 SAFETY AND FEASIBILITY OF CATHETER ABLATION OF SUPRAVENTRICULAR TACHYCARDIAS IN OUTPATIENTS

*G. Barbato, *V. Carinci, *F. Pergolini, *G. Di Pasquale *Cardiology Unit, Maggiore Hospital, Bologna, Italy

Introduction: Nowadays catheter ablation for supraventricular tachycardias (SVT) requires patient hospitalization in many centres. We report our initial experience in hospital outpatients.

Methods: Twelve patients with SVT (10 typical atrial flutter, 2 AV nodal reentrant tachycardia) were selected for treatment as outpatients between 1 January 1 2007 and 1 April 2007. The mean age of the population was 53 years. In all cases, arrhythmia was tolerated well. The absence of cardiopathy was requested (mean EF 60%). The out-of-hospital treatment was discussed with the patients. In cases of atrial flutter, the procedure was performed with anticoagulation therapy.

Results: The procedure was successful in 12 cases out of 12, with a mean procedure duration of 65 ± 23 min. In all 12 cases, the patient was discharged on the day of ablation. The mean duration of observation was 08 ± 01 h. The next day an ambulatory visit was planned. At follow-up study, no patients had a clinically significant complication.

Conclusions: Some SVT, such as typical atrial flutter or AV nodal re-entrant tachycardia, can be treated safely on an outpatient basis.

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3.5 USE OF PROPOFOL IN THE ELECTROPHYSIOLOGY LABORATORY WITHOUT ANAESTHESIOLOGIST SUPPORT: RESULTS FROM 373 CONSECUTIVE PATIENTS

*G. Barbato, *V. Carinci, *F. Pergolini, *G. Di Pasquale *Cardiology Unit, Maggiore Hospital, Bologna, Italy

Introduction: In the EP laboratory patient sedation is a daily necessity. We report our experience with the use of propofol without anaesthesiologist support.

Methods: From January 2004 to December 2006 propofol was given to 373 patients, with 2 protocol: (A) continuous infusion (1–2 mg/kg/h) during long lasting procedure (246 pts) and (B) bolus (10–20 mg ev) administration for cardioversion or device testing (127 pts). O2 saturation and arterial pressure were monitored. The patients were always able to answer questions aloud. The anaesthesiologist was available on call.

Results: The groups differed from each other in mean age (54 years A, 68 years B), presence of cardiopathy (12% vs. 82%), and mean EF (55 vs. 36%). The mean propofol dose of protocol (A) was 1.8 mg/Kg/min (range 1.2–3 mg/Kg/min), of protocol (B) 50 mg (range 35–75 mg). No complications were documented. All patients recovered within a few minutes and did not report unpleasant memories. The anaesthesiologist's presence was never requested.

Conclusions: In the EP laboratory propofol can be safely administrated, even to severe patients, with an anaesthesiologist back up.

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3.6 PAIN CONTROL DURING COMPLEX RADIOFREQUENCY CATHETER ABLATION: DO ANALGESICS INTERFERE WITH ELECTROPHYSIOLOGIC PARAMETERS?

*M. Lagrotta, *F. Cantù, *P. De Filippo, *L. Lorini, *A. Gavazzi *Cardiovascular Department, Ospedali Riuniti di Bergamo, Bergamo, Italy

Introduction: Radiofrequency catheter ablation (RFCA) may evoke pain. We evaluated an analgesic mixture composed of clonidine, tramadol and the antiemetic ondansetron in 10 adults with complex supraventricular tachycardia (SVT).

Methods: Premedication: midazolam 30 minutes before the procedure. Consciousness status and pain intensity were evaluated with the sedation (SED) and verbal pain (VPS) score; and discomfort with movement score (0 = no movement; 1 = movements without interference with manouvers; 2 = restless; 3 = need for sedation). Electrophysiologic parameters, at zero and 30 minutes after infusion, were: effective refractory period, atrio-ventricular/ventricular-atrial block cycle length and sinus node recovery time. SVT induction scores ranged from one (induced without drugs) to three (not inducible under analgesics).

Results: The mean procedure duration was 4 ± 1 hours. No vomiting, respiratory or consciousness depression were observed. One patient had VPS eight. Two patients had one in scale of movements. We observed no significant changes in cardiac eletrophysiology parameters after administration of analgesic mixture and no variation in the induction of the target tachycardia.

Conclusions: Analgesic mixture seems to ameliorate complex RFCA tolerability without interfering with eletrophysiology and induction of the target tachycardia.

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3.7 ATRIAL TACHYCARDIAS ASSOCIATED WITH A GIANT LEFT ATRIAL ANEURYSM: CATHETER ABLATION AND IMAGING STUDIES

*R.M. John, *C. Wald *Lahey Clinic Medical Center, Burlington, USA

Introduction: Idiopathic or congenital aneurysm of the left atrium usually manifests with atrial arrhythmias or embolic stroke. Surgical resection reportedly cures the arrhythmia but arrhythmia mechanisms have hitherto been ill defined.

Method and Results: A 50-year-old male presented with atrial tachycardia at a cycle length of 360 msec. Cardiac gated spiral CT angiography revealed a discrete aneurysm 6.5 cm in diameter, arising from the inferior-lateral left atrium, separate from a normal-sized left atrial appendage. Voltage mapping revealed electrical silence within the aneurysm, with fragmented electrograms anteriorly. Pacing at this site entrained tachycardia with concealed fusion and post-pacing interval identical to tachycardia cycle length. Linear RF ablation to bridge the aneurysmal scar to the anterior mitral annulus terminated the tachycardia, rendering it non-inducible. A second atrial tachycardia at 230 msec on isoproterenol was localized to the left inferior pulmonary vein, where focal ablation based on pre-systolic electrograms terminated tachycardia. The patient remains symptom-free.

Conclusions: To our knowledge, this is the first report of successful catheter ablation of atrial tachycardias occurring in relation to idiopathic giant left atrial aneurysm.

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4. AV NODE REENTRY TACHYCARDIA/ATRIOVENTRICULAR REENTRY TACHYCARDIA

4.1 A COMPARATIVE ANALYSIS OF ANTEGRADE AND RETROGRADE CONDUCTION PATTERN IN SINGLE AND DUAL AV NODAL PATHWAY

*D. Tanubudi, *Y. Yuniadi, *M. Munawar *Department of Cardiology and Vascular Medicine University of Indonesia, National Cardiac Centre Harapan Kita, Jakarta, Indonesia

Introduction: The anatomy and physiology of the atrioventricular (AV) node is widely described in experimental and clinical studies. The pattern of antegrade and retrograde conduction and refractory period using His bundle electrogram recordings, incremental atrial and ventricular pacing and extrastimulus technique had already been studied. However, no clear separation has been found between people with single and dual pathways of AV nodal conduction. The aim of this study is to analyze comparatively the pattern of antegrade and retrograde conduction in people with a single and dual AV nodal pathway.

Methods: Fifty-five patients (27 men and 28 women aged from 38 to 66 years), who had undergone an electrophysiology exam due to variable arrhythmia problems, were included in this study, except those suffering from AVRT. The effective refractory period (ERP) of AV nodal antegrade and retrograde conduction in people with both a single and dual pathway were comparatively analyzed.

Results: In the single pathway group the ERP of antegrade was 277.04 ± 70.59, whereas the ERP of retrograde was 539.75 ± 148.53 (p = <0.001). In the dual pathway group the ERP of antegrade was 257.14 ± 54.83, and the ERP of retrograde was 265.61 ± 103.43 (p = 0.676).

Conclusions: In the single pathway group, AV nodal antegrade conduction was significantly better than retrograde conduction. In the dual pathway group, the antegrade conduction appeared to be equal to the retrograde conduction.

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4.2 CARDIAC MEMORY (T-WAVE MEMORY) AFTER ABLATION OF POSTEROSEPTAL ACCESSORY PATHWAY

*I. Trajkov, *D. Kovacevic, *L. Poposka, *V. Boskov, *N. Gjorgov *Institute for Heart Diseases, University Clinical Centre, University of Sts Cyril and Methodius, Skopje, Republic of Macedonia

Introduction: Cardiac memory is a phenomenon characterized by transient T-wave abnormalities occurring during normal sinus rhythm after a period of altered ventricular depolarization, where the T-wave vector has the same direction as the vector of the previous altered QRS complex (T-wave inversion). It is a form of electrical remodelling of the ventricular, where T-wave follows (“remembers”) a previously altered QRS vector.

Methods and Results: During a 6-year period (from 2002 until the end of 2006), 525 consecutive patients underwent an electrophysiological study in the Electrophysiology Laboratory of the Institute for Heart Diseases in the University Clinical Centre in Skopje, Macedonia. One hundred and one patients underwent an accessory pathway (AP) ablation for atrioventricular re-entry tachycardia (AVRT). Forty-two were without delta wave on the surface electrocardiogram (concealed accessory pathways), 58 patients had an open form of accessory pathways with delta wave present on surface EKG (Wolff-Parkinson-White syndrome), and one patient had Mahaim form accessory pathway. According to the location of the accessory pathways, 17 patients (29.3%) had an accessory pathway in the right posteroseptal region. From that region we noticed the highest proportion of T-wave inversion. Electrocardiographic changes were followed in the frontal plane (leads II, III, and aVF). Electrocardiogram (ECG) signs for cardiac memory were present in 16 out of 17 patients (94.1%) within 24 hours post AP ablation. The post-ablation T-wave inversion had the same vector as the vector of the pre-excited QRS complex (delta wave) creating inferior T-wave inversions. There was no correlation between the number or the duration of the energy application and the extent of cardiac memory post ablation. After a three-month follow up, 90% of cases of surface electrocardiogram showed complete normalization. None of the patients with T-wave inversion after ablation had a recurrence of pre-excitation or tachycardia during the 12-month follow up period.

Conclusions: T-wave inversion in leads II, III and aVF, along with disappearance of the delta wave after ablation of the accessory pathway in the patients with Wolff-Parkinson-White syndrome, can be considered a valid marker for successful ablation.

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4.3 PROSPECTIVE ANALYSIS OF NON-INDUCIBILITY PREDICTORS AFTER RADIOFREQUENCY ABLATION OF AVNRT: IMPORTANCE OF THE RELATIONSHIP BETWEEN BASAL CYCLE LENGTH AND MEAN CYCLE LENGTH OF JUNCTIONAL RHYTHM

*J. Jimenez-Candil, *J. Morinigo, *C. Ledesma, *C. Albarran, *I. Cruz, *C.M. Luengo *Arrhythmias Unit, Cardiology Department, Universtiy Hospital, Salamanca, Spain

Introduction: Radiofrequency ablation (RFAb) of atrioventricular nodal reentrant tachycardias (AVNRT) relies on non-inducibile (NI) tachycardia as a success criterion. Previous studies have shown that: 1- the achievement of junctional beats (JB) or rhythms (JR) during the applications (Ap) is sensitive but not specific to success; 2- effective Ap present more JB, but the mean cycle length (CL) of JR is similar. We propose that the CL of JR depends on basal CL pre-RF and varies widely (related to the autonomic tone and drugs used in induction). In the case of a positive correlation, the ratio pre-RF CL/CL of JR (CLratio) could be a marker of NI.

Methods: We prospectively analyzed 319 Ap performed in 69 consecutive P (mean Ap/P: 4.6 ± 2.4) with reproducible AVNRT (defined as at least 3 consecutive inductions with the same protocol). RFAb was performed by following an anatomical approach, with Ap predefined in terms of maximum duration (30 seconds), power (45 watts) and temperature (55°C). After each Ap, the induction protocol was repeated.

Results: We obtained NI in all P after the occurrence of JB or JR. There was a significant correlation between the pre-RF CL and the CL of the subsequent JR (Pearson = 0.52; p < 0.001); in effective Ap, CL of JR was longer if preRF CL>700 ms compared with <700 (621 ± 122 vs 514 ± 89; p < 0.001). Ap with NI versus those with persistent inducibility presented: similar pre-RF CL (707 ± 104 vs 705 ± 106 ms; p = 0.9), higher number of cumulative JB (CJB) (23 ± 14 vs 7 ± 10; p < 0.001), and higher CLratio (1.43 ± 0.25 vs 1.17 ± 0.21; p < 0.001). Two variables correlated adequately with NI (defined as an area under ROC-curve>0.80): CLratio (c = 0.83; p < 0.001) and CJB (c = 0.81; p < 0.001). The best cut-off points were: CLratio>1.24 (sensitivity, specificity: 88, 80%) and CJB > 10 (98, 72%). Any value of CJB presented a positive predictive value for NI higher than 70%. However, Ap with CJB>10 and CLratio>1.24 were associated with a higher frequency of NI: 89 vs 4% (95% CI: 4–17; p < 0.001) and achieved NI in 54/57 (95%) P. During follow-up (median: 10 months) there were no recurrences.

Conclusions: 1- The JR-CL identified during RFAb depends on pre-RF CL; 2- CLratio correlates with the probability of NI and increases the accuracy of CJB as a marker of success; 3- Ap with >10 CJB and CLratio >1.24 achieve NI in 95% of P.

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4.4 SAVING AV-CONDUCTION IN PRESENCE OF EXCEPTIONAL INFEROSEPTAL FAST PATHWAY-LOCATION THROUGH 3-DIMENSIONALLY GUIDED SLOW-PATHWAY-ABLATION IN PATIENTS WITH AV-NODAL REENTRY-TACHYCARDIA

*U. Backenkoehler, *O. Nemitz, *K. Wellnitz, *W. Terres *AKH Celle, Celle, Germany

Introduction: In 9% of patients with AV-nodal re*-entry tachycardia (AVNRT) the fast pathway (FP) is localized in the mid-inferoseptal regions close to the slow pathway (SP). We investigated whether in these special cases the application of a 3-dimensional mapping system (3DM) may offer significant benefits compared to ablation through endocardial (EA) map and fluoroscopy only.

Methods: Out of 257 consecutively investigated patients 26 displaying shortest stimulus-H-interval in the mid-inferoseptal region during EA-map were prospectively randomized to two different groups A and B. Group A patients (n = 13) were investigated using a 3DM (LocaLisa® or ENSITE®) in addition to conventional mapping as deployed in group B (n = 13). Primary end-point was defined as a statistically significant difference in number and total duration of RF impulses, whereas secondary end-points were defined as fluoroscopy time, radiation dose and occurrence of post-interventional AV-nodal conduction disturbances.

Results: In group A patients the use of 3DM significantly reduced the number of effective RF impulses (6.4 ± 2.5) needed for successful SP ablation as compared to group B (11.1 ± 5.2, p = 0.007, ANOVA). The total duration of impulses in group A (161 ± 108 sec) was significantly shorter compared to group B (562 ± 251 sec, p ≤ 0.0005, ANOVA). Fluoroscopy time (5.4 ± 3.5 min in group A vs 11.6 ± 5.6 min in group B, p = 0.002, ANOVA) as well as total dose of radiation (p ≤ 0.0005, ANOVA) were significantly lower in group A as compared to group B. Post-interventional conduction disturbances were not observed in any patient.

Conclusions: Application of a 3DM in patients with AV-nodal re-entry tachycardia and critical mid-inferoseptal location of the FP or the AVN close to the target ablation site of the SP may allow a significant reduction in number and duration of RF-applications, fluoroscopy time and radiation dose compared to conventional ablation techniques.

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5. SUDDEN DEATH: RISK STRATIFICATION

5.1 PROGNOSTIC VALUE OF T-WAVE ALTERNANS FOR SUDDEN DEATH RISK STRATIFICATION IN ATHLETES WITH VENTRICULAR ARRHYTHMIAS

*C. Pedrinazzi, *O. Durin, *M. Nanetti, *G. Donato, *G. Inama *Department of Cardiology, Ospedale Maggiore, Crema, Italy

Introduction: The aim of our study was to evaluate the role of TWA to stratify the risk of sudden cardiac death in athletes (Ath) with complex ventricular arrhythmias (VA), and to document a possible correlation between TWA and electrophysiological testing (EPS) results.

Methods: We studied 85 Ath with VA (61 M, mean age 32 ± 11 years). In all cases, a cardiological evaluation was performed, including TWA and EPS. The patients were evaluated during a follow-up of 30 ± 21 months. The end-point was the occurrence of Sudden Death (SD) or malignant ventricular tachyarrhythmias (VT).

Results: TWA was negative in 57 Ath (68%), positive in 15 (18%) and indeterminate in 13 (14%), with significant correlation between negative TWA and negative EPS (p < 0.001), positive TWA and positive EPS (p < 0.001), and abnormal TWA (positive + indeterminate) and positive EPS (p < 0.001). During follow up, we observed a significant difference in end-point occurrence (VT or SD) between Ath with negative or abnormal TWA (0% vs. 25%, p < 0.01) and between Ath with negative or positive EPS (0% vs. 37%).

Conclusions: TWA seems useful for prognostic stratification of Ath with VA.

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5.2 QT DYNAMICITY AND TIME TO ARTERY OPENING IN PATIENTS WITH MYOCARDIAL INFARCTION WITH ST ELEVATIONS

*T. Novotny, *M. Sisakova, *M. Poloczek, *I. Dohnalova, *I. Kyselova, *L. Dostalova, *A. Florianova, *P. Kala, *O. Toman, *P. Vit, *J. Spinar *Department of Internal Medicine and Cardiology, Department of Paediatrics II, University Hospital Brno, Brno, Czech Republic

Introduction: QT dynamicity is a marker of ventricular repolarization used in risk stratification of cardiac death. The aim of this study was to correlate QT dynamicity parameters with time to artery opening and Q wave evolution after myocardial infarction with ST elevations (STEMI).

Methods: A 24-hour ECG monitoring was performed in 112 patients 48–72 hours after acute STEMI (treated with direct angioplasty). The QT dynamicity (slope of linear QT/RR regression line) was automatically analyzed from 24-hour ECG recordings (QT Guard, MARS Unity Workstation, GE Medical). Occurrence of pathologic Q wave was assessed on 12-lead ECG 48 hours after STEMI.

Results: Infarction artery was opened in 120 minutes from beginning of symptoms in 10 patients (group A), 121–240 min in 53 patients (group B), 241–360 min in 31 patients (group C) and more than 360 min in 18 patients (group D). QT/RR slopes in all these groups were the same (A: 0.168 ± 0.045, B: 0.216 ± 0.076, C: 0.225 ± 0.095, D: 0.206 ± 0.089. A vs. B: p = 0.066, A vs. C: p = 0.058, A vs. D: p = 0.27, B vs. C: p = 0.638, B vs. D: p = 0.44, C vs. D: p = 0.258). Pathologic Q wave evolved in 86 patients (group E); in 46 patients no Q wave was observed (group F). The QT/RR slope was significantly steeper in group G compared to group H (0.229 ± 0.118 vs. 0.181 ± 0.099, p = 0.007).

Conclusions: No relationship between time at the artery opening and the QT dynamicity was found. The QT/RR slope is steeper in patients with Q wave evolution after STEMI, confirming that they are high-risk individuals.

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5.3 P-WAVE MORPHOLOGY AND SUDDEN CARDIAC DEATH AFTER ACUTE MYOCARDIAL INFARCTION

*J.S. Perkiömäki, *M. Hyytinen-Oinas, *J. Junttila, *M. Karsikas, *T. Seppänen, *H.V. Huikuri *Division of Cardiology, Department of Medicine and Information Processing Laboratory of the Technical Department, University of Oulu, Oulu, Finland

Introduction: The aim of this study is to assess whether P-wave loop based parameters predict sudden cardiac death during a follow-up of patients with AMI.

Methods: Digital high-resolution ECG recordings in orthogonal Frank leads (X, Y, Z) were obtained in 424 patients between days 5 and 14 after AMI. Using custom-made software, P-wave loop parameters, such as P-wave loop dispersion (PWLD), were analyzed.

Results: The patients were followed up for 60 months. During the follow up, 11 (3%) patients experienced a sudden cardiac death, 20 (5%) a non-sudden cardiac death, and 15 (4%) a non-cardiac death. In an unvaried comparison, PWLD had a significant association with the occurrence of sudden cardiac death (p = 0.01), but was not associated with the risk for non-sudden cardiac (p = 0.4) or non-cardiac death (p = 0.9). When age, gender, left ventricular ejection fraction (EF), NYHA class and diabetes were included in the Cox hazards model, PWLD still significantly predicted sudden cardiac death (HR = 1.3, 95% CIs from 1.06 to 1.5, for each one unit increase in PWLD, p = 0.009). PWLD showed no association with EF (r =−0.02, p = 0.7).

Conclusions: PWLD specifically predicts sudden cardiac death in post-AMI patients.

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5.4 CAN QT-DISPERSION PREDICT POST-MI COMPLICATIONS?

*S.F. Jalali, *K. Hajian, *R. Rastghar *Babol University of Medical Sciences, Babol, Iran

Introduction: Many investigators consider QT dispersion (QTd) to reflect heterogeneity of ventricular repolarization and its predictive power in arrhythmias and sudden cardiac death, after myocardial infarction (MI).

Methods: We studied the relation between QTd – as an independent factor – and hospital morbidity and post-discharge mortality in patients with acute MI. The study included 200 patients with acute MI admitted to our hospital. Information on age, sex, medical history, location and type of MI, left ventricular ejection fraction (LVEF), and duration of hospitalization was collected.

Results: QTd (maximal minus minimal QT interval) was calculated in standard 12-lead electrocardiogram. Mean QTd in all cases was 74 ± 9 ms. In 6 patients who died during 6-month follow-up, the mean QTd was 103 ± 11 ms, and was significantly higher than in survivors (QTd mean: 74 ± 8 ms) (p < 0.05). The mean QTd with complicated acute MI was 81 ± 10 ms, and showed no significant difference from that of the non-complicated group (QTd mean: 72 ± 8 ms (p > 0.05)). We divided complicated patients into four groups: bradyarrhythmia and conductive disturbance in 14 cases (QTd mean: 79 ± 9 ms), atrial tachyarrhythmia in 7 cases (QTd mean: 73 ± 14 ms), ventricular arrhythmia in 16 cases (QTd mean: 86 ± 11 ms) and acute heart failure and cardiogenic shock in 9 cases (QTd mean: 92 ± 3 ms).

Conclusions: One-way ANOVA test (p > 0.05) revealed no significant differences among these four groups. In our study there was no significant relationship between QTd and LVEF (Pearson's coefficient correlation, p = 0.78, r = 0.16). QTd can be used as a simple and easily available criterion for predicting short-term mortality after MI. In this study there was no definite relationship between QTd and other complications or LVEF after MI.

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5.5 SERUM LEVEL OF INTERLEUKINE 6 (IL-6), TNF-ALPHA AND ENDOTHELIN-1 (ET-1) AND VENTRICULAR ARRHYTHMIAS IN PATIENTS AFTER MYOCARDIAL INFARCTION

*D. Mroczek-Czernecka, *A.Z. Pietrucha, *J. Nessler, *M. Węgrzynowska, *M. Stępniewski, *W. Piwowarska *Coronary Disease Department, Institute of Cardiology, Medical School of Jagiellonian University, John Paul II Hospital, Cracow, Poland

Introduction: The aim of study was the evaluation of interleukine 6 (IL-6), TNF-alpha and Endothelin-1 (ET-1) serum level in patients after myocardial infarction in relation to the presence of ventricular arrhythmias recorded in 24-hour ECG Holter monitoring.

Methods: We observed 90 pts aged between 40 and 74 years with coronary artery disease, after myocardial infarction and ventricular arrhythmias (VA). All pts were divided into 2 groups: Group I – 40 pts with the presence of IVA and IVB VA class according to Lown scale, Group II – 50 pts with I to III VA class. An echocardiography examination with global and segmental left ventricle ejection function evaluation and 24-hour ECG Holter monitoring were performed in all pts on admission to the Department. Serum levels of IL-6, TNF-alpha and ET-1 were assessed in these pts by immune-enzymatic assay.

Results: Left ventricle ejection fraction (LVEF) ranged from 25.5% to 55% in group I (pts with IV VA class) and 35.5% to 60% in Group II (I-III VA Class). Serum level of IL-6 was significantly higher in group I – 16.2 ± 13.15 pg/ml (3.60–29.15 pg/ml) in comparison to Group II – 3.92 ± 5.92 pg/ml (0.95–10.02 pg/ml). TNF-alpha serum level was also significantly higher in Group I pts – 220.71 ± 150.4 pg/ml (0.00 to 680.550 pg/ml) than in group II – 105.1 ± 99.0 pg/ml (0.0 to 290.54 pg/ml). The highest IL-6 and TNF-alpha serum concentration was noticed in 15 pts with complex ventricular arrhythmias and significant systolic left ventricle dysfunction (LVEF 25.5–30.5%, x-28.7%) – group IA. IL-6 and TNF-alpha serum levels were also significantly higher in subgroup IA than in groups I and II (respectively: IL-6–25.2 ± 4.2 pg/ml; TNF-alpha – 521.1 ± 111.2 pg/ml). ET-1 serum level did not differ significantly between groups I and II (21.71 ± 12.15 vs. 16.71 ± 4.92 pg/ml).

Conclusions:

  • 1
    IL-6 and TNF-alpha serum levels were significantly higher in patients with coronary artery disease after myocardial infarction with concomitant IVA and IVB class ventricular arrhythmias.
  • 2
    The highest values of IL-6 and TNF-alpha were observed in patients with severe systolic dysfunction after myocardial infarction
  • 3
    ET-1 serum level did not differ significantly between post-MI patients with single ventricular premature beats and complex ventricular arrhythmias.

5.6 ADDITIONAL RISK STRATIFICATION OF ISCHEMIC PATIENTS WITH DEPRESSED VENTRICULAR FUNCTION ON THE BASIS OF EJECTION FRACTION LEVELS: DATA FROM CAMI GUIDE STUDY

*C. Vasco, *C. Battaglia, **M. Landolina, ***M. Sasselli, ****G. De Martino, †P. De Marchi, ††F. Turreni, †††G. Zaccone, ††††M. Romanò, ‡G.B. Del Giudice, ‡‡G. Arone, ‡‡G. Raciti, ‡‡‡F. Bellocci *Azienda Ospedaliera Umberto I, Enna ; **IRCCS Policlinico San Matteo, Pavia ; ***Ospedale Sandro Pertini, Rome ; ****Osp S. Camillo de Lellis, Rieti ; †A.O. SS. Antonio e Biagio e Cesare Arrigo, Alessandria ; ††Ospedale Belcolle, Viterbo ; †††P.O. San Giacomo, Novi Ligure ; ††††Ospedale Civile, Vigevano ; ‡Ospedale S. Giovanni Addolorata, Rome ; ‡‡Boston Scientific, Milan ; ‡‡‡Policlinico Agostino Gemelli, Rome; Italy

Introduction: Ischemic patients with depressed ventricular function meet indications for ICD according to current guidelines. Additional stratification based on Ejection fraction (EF) values may help to identify those patients at higher risk.

Methods: Using the CAMI GUIDE study population, proportions of patients with EF<25% and between 26 and 30% were compared for clinical characteristics and for events during one year of follow-up.

Results: Of 302 patients with EF ≤ 30%, 86 had EF < 25% and 216 had EF between 26% and 30%. With the exception of NYHA class (55% vs. 36%, p < 0.01), the clinical characteristics of these two groups were not statistically different (male gender: 89% vs. 97%; previous CABG: 27% vs. 33%; HF history: 73% vs. 65%; hypertension: 59% vs. 49%; atrial fibrillation: 17% vs. 13%; LBBB: 40% vs. 40%; age: 67 ± 9 vs. 67 ± 10; QRS: 130 ± 34 vs. 125 ± 34). Over 12 months’ follow up, mortality (11% vs. 8%), ventricular arrhythmias (14% vs. 12%) and cardiac hospitalization (9% vs. 7%) did not differ significantly.

Conclusions: Ischemic patients with EF < 25% indicated for primary prevention with ICD share similar clinical characteristics and risks to patients with EF between 26% and 30%. Further risk stratification on the basis of other parameters will be provided by the CAMI GUIDE study.

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5.7 CLINICAL AND INFLAMMATORY PREDICTORS OF OCCURRENCE OF VENTRICULAR TACHYCARDIA AND VENTRICULAR FIBRILLATION IN MADIT II-LIKE PATIENTS

*G. Giubilato, *L.M. Biasucci, *N. Vitulano, *A. Poggiaroni, *T. Sanna, *A. Dello Russo, *G. Pelargonio, *M. Casella, *F. Bellocci, *F. Crea *Institute of Cardiology, Catholic University of the Sacred Heart, Policlinico Gemelli, Rome, Italy

Introduction: Implantable Cardioverter Defibrillators (ICDs) have been proven to reduce arrhythmic death. We sought to assess whether, in patients with ICD, common clinical risk factors – the lack of revascularization and CRP levels – predict occurrence of appropriate ICD intervention for sustained ventricular tachycardia (VT) and/or ventricular fibrillation (VF).

Methods: We enrolled 65 ICD recipients with a prior myocardial infarction and a left ventricular ejection fraction ≤30% (MADIT II-like criteria of inclusion). In all patients we measured CRP during hospitalization and subsequently during a 12 ± 4-month follow-up we determined the incidence of appropriate ICD therapies for VT/FV by reviewing ICD-stored electrograms.

Results: At follow up, 18/65 (28%) patients had VT/VF triggering ICD therapy. In a logistic regression analysis, CRP was independently associated with occurrence of VT/VF (OR 3.3, CI 1–12).

Conclusions: CRP levels >3 mg/L prospectively predict recurrence of VT/VF in patients with ICD independently of common risk factors and revascularization.

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6. NON SUSTAINED VENTRICULAR ARRHYTHMIAS/ICD ISSUES

6.1 VENTRICULAR TACHYCARDIA IN NON-COMPACTION OF LEFT VENTRICLE: IS THIS A FREQUENT COMPLICATION?

‡‡‡‡G. Fazio, *G. Corrado, ***E. Zachara, **C. Rapezzi, **A.K. Sulafa, L. Utera, †C. Pizzuto, C. Stollberger, *L. Soriani, ††J. Finsterer, †††A. Benatar, G. Di Gesaro, G. Novo, ‡Y. Cavusoglu, †M. Baumhakel, ‡‡F. Drago, ‡‡‡S. Carerj, ‡‡‡‡S. Pipitone, S. Novo Department of Cardiology, University of Palermo, Italy; *Valduce Hospital, Como, Italy ; **University of Bologna and S. Orsola-Malpighi Hospital, Bologna, Italy ; ***S. Camillo-Forlanini Hospital, Rome, Italy ; ****Riyadh, Saudi Arabia ; †Krankenanstalt, Wien, Austria ; ††Krankenanstalt Rudolfstiftung, Wien, Austria ; †††Free University of Brussels, Belgium ; ††††Universitatskliniken des Saarlandes, Hamburg/Saar, Germany ; ‡Osmangazi University, Eskisehir, Turkey ; ‡‡Bambino Gesù Hospital, Rome, Italy ; ‡‡‡University of Messina, Messina, Italy ; ‡‡‡‡Casa del Sole Hospital, Palermo, Italy

Introduction: Isolated left ventricular non-compaction is the result of incomplete myocardial morphogenesis, leading to persistence of the embryonic myocardium. The condition is characterized by an excessively prominent trabecular meshwork and deep intertrabecular recesses of the left ventricle. Whether these intertrabecular recesses are a favourable substrate for ventricular arrhythmias is unclear. Some reports have found that fatal ventricular arrhythmias may occur in approximately half of the patients. In this report this association was investigated.

Methods and Results: We evaluated a continuous series of 238 patients suffering from non-compaction. Periodic Holter monitoring was performed every 6 months for 4 years. Only 11 patients had documented ventricular tachycardia, which was sustained in 2 cases and non-sustained in 9. In no cases ventricular fibrillation was observed.

Conclusions: Non-compaction alone does not seem to be a risk factor for malignant ventricular arrhythmias.

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6.2 MYOCARDITIS IN ATHLETES: EPIDEMIOLOGY, PROGNOSIS AND MEDICAL-LEGAL ASPECTS

*E. Moccia, **F. Naccarella, *D. Vasapollo, **C. Felicani, ***M. Jasonni, **D. Affinito, ****A. Casotti, **G. Lepera *Medicina Legale, Università di Bologna, Bologna, Italy **Cardiologia Azienda USL, Bologna, Italy ***Cattedra di Diritto, Università di Modena, Modena, Italy ****Medicina dello Sport, Azienda USL, Bologna, Italy

Introduction: Infective myocarditis (IM) is one cause of sudden death (SD) in athletes. Thus, a protocol including non-invasive cardiology tests (NICT) and laboratory profile (LP) was set-up.

Methods: 119 young athletes (SA) were selected in that they suffered from frequent ventricular arrhythmias (VA) and worsening of a pre-existing VA, with or without evolving STT changes. They underwent NICT and LP, including IgM, IgA and IgG versus the most common viral and bacterial infections (AI).

Results: 56 of the 119 subjects (47%) showed LP compatible with AI. Twenty-eight of the 56 subjects (50%) with positive LP also had clinical signs of an acute systemic illness (SI) with concomitant myocardial involvement (MI). In 26 of 28, SA was discontinued, but was resumed in 20 after 6–9 months. In 28 pts with LP, IM was due in 12 cases to Echo Coksackie B, Enterovirus, in 4 cases to Toxoplasmosis, of which 1 lethal and 1 evolving to dilated cardiomyopathy, in 4 cases to infectious mononucleosis, in 2 cases to flu virus or Adenovirus, in 2 cases to Mycoplasma Pneumoniae, in 2 cases to Herpes Virus or Herpes Zoster infections, in 1 case to borelliosis or Lyme disease and in 1 case to Legionellosis. We recorded 2 deaths in the acute phase and 1 death in the follow-up.

Conclusions: The signs of SI could be identified in SA (47%). Clinical pictures of an upper respiratory tract or low bowel infection, in association with a typical LP, can be regarded as SI. Signs of pericarditis and or ST changes, frequent VA or the worsening of VA can be considered highly indicative of IM involvement. SA should be discontinued for 6–9 months. Strict adherence to guidelines and to the proposed protocol for screening and follow-up of suspected myocarditis in athletes is significant with regard to eliminating medical-legal controversies.

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6.3 THREE-DIMENSIONAL ELECTROANATOMIC VOLTAGE MAPPING IN COMPETITIVE ATHLETES WITH FREQUENT NON-SUSTAINED VENTRICULAR ARRHYTHMIAS AND NORMAL ELECTROPHYSIOLOGICAL STUDY

*R. Biddau, *A. Dello Russo, *G.M. Casella Pelargonio, *M. Pieroni, *G. Trotta, *F. Marzo, *G. Bencardino, *M.L. Narducci, *A. Martino, *P. Santarelli, *P. Zeppilli, *F. Bellocci *Catholic University of Sacred Heart, Department of Cardiology and Department of Sport Medicine, Rome, Italy

Introduction: CARTO mapping may help distinguishing normal from diseased hearts in young athletes with non-sustained ventricular arrhythmias (NSVA) Methods: eleven athletes (10 males, mean age 25) with NSVA underwent a complete non-invasive work-up, electrophysiological study (EPS), Carto mapping and Endomyocardial Biopsy (EMB).

Results: Eight (72%) athletes had monomorfic ventricular premature beats (VPB), 6 of which (75%) with left bundle branch block morphology. Two had syncope, 3 had palpitations, 1 had familiar history of sudden death, 1 had clinical history of myocarditis. VPB were suppressed by exercise in 3 (27%), signal-averaged-ECG was positive in 4 (36%). All had negative EPS. Right ventricular CARTO mapping was abnormal in 6 (group A), normal (Group B) in 5. Five (83%) in Group A and 2 (40%) in Group B showed Echocardiographic or cMRI structural/functional abnormalities (p = 0.02). In group A, 4 (66%) had pathological EMB: 2 chronic inflammatory cardiomyopathies and 2 fibro-fatty replacement pathognomonic of Arrhythmogenic Right Ventricular Dysplasia. In group B no pathological EMB was found (p = 0.008).

Conclusions: In athletes with NSVA, an abnormal electroanatomic bipolar voltage correlates with structural/functional abnormalities.

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6.4 DIAGNOSTIC FUNCTIONS OF PACEMAKERS AND VENTRICULAR ARRHYTHMIAS: VAPP MONOCENTRIC STUDY

*M. Guenoun, *M. Hero *Clinique Bouchard, Marseilles, France

Introduction: The goal of this study was to evaluate the usefulness of memory functions (MF) based on EGM recordings to describe the incidence and characteristics of ventricular arrhythmias (VA) in a population of patients with pacemaker.

Methods and Results: A series of 93 consecutive pts, 66% male, mean age 75 ± 10 yrs, implanted for AVB (41%) and SD (55%) were evaluated during follow-up visits (f/u) between January and June 2006. Four hundred and ninety-seven f/u visits were analyzed during a period ranging from 2 to 81 months after implantation, and VA (defined as at least 5 consecutive QRS complexes with a rate grade >175/mn) validated by EGMs. Number of episodes, duration and heart rate of the longest arrhythmia episodes were recorded. 24 pts (26%) showed VA in 88 f/u visits (18%). The avg. number of episodes was 9 per f/u visits (1–140), avg. duration was 4 ± 4 seconds (1–27 sec), and avg. rate was 214 ± 33 bpm (174–307). All the episodes were classified as non-sustained ventricular tachycardia (NSVT). The ejection fraction was 51 ± 11%. 84% of patients showed organic cardiac disease: CAD (12), HCM (4) and DCM (4). Statistical analysis showed that age, pacing indication, pacing mode and cumulated percentage of pacing were not correlated to the occurrence of NSVT.

Conclusions: VA are observed in … of pts implanted for standard pacing indications. A major determining factor in the occurrence of NSVT is the presence of an associated organic cardiac disease. MF featuring EGM recordings are tool for reliable diagnosis and monitoring of these events. Further studies are required to evaluate the prognostic significance of these arrhythmias.

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6.5 SPECTRAL DYNAMICS EVALUATION OF VENTRICULAR FIBRILLATION (VF) IN PATIENTS WITH LOW EJECTION FRACTION (EF)

*M. Bernasconi, *G. Guenzati, *M. Marzegalli, *S. Guidotti, *T. De Santo *Unità Operativa di Cardiologia Osp. San Carlo Borromeo, Milan, Italy Medtronic Italia, Sesto San Giovanni, Italy

Introduction: Some authors have shown a correlation between high spectral power VF and successful resuscitation, suggesting a higher arrhythmia co-ordination. No data are available about early stage VF in patients with severe depression of LV function.

Methods: One hundred and twelve pts (95 M age 65 ± 14 years) were analyzed: 88 pts had ischaemic and 24 dilated cardiomiopathy. EF<30%:88 pts; >30%:24 pts. EGM were stored during VF induction test at implant: EGM1 (Vtip-Vring channel), EGM2 (Can-coil). VF episodes were divided into 2 consecutive sec segments. Peak Power Frequency (Peak) and 50% Power Frequency (Freq) were measured in each segment and channel.

Results: In all pts spectral density was concentrated in a narrow band spectrum and greater in EGM1 vs. EGM2:

 Peak (Hz)Freq(Hz)
  1. *p < 0.0001, **p = 0.001.

EGM1(all pts)5.5 ± 2.48 ± 2.8
EGM2 (all pts)4.4 ± 1.1**5.0 ± 1.4*

No Freq and Peak difference was noticed in EF < 30% vs. EF > 30%pts. In all pts, EGM2-spectral density increased between the first and second segment.

Conclusions: In low EF patients, VF early stage pattern looks like a synchronized rhythm. EGM1 Freq is greater, reflecting higher synchronization; spectral power reaches a climax in 2–3 sec. These parameters could be used to improve detection and VF ICD therapy.

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6.6 RISK STRATIFICATION OF ARRHYTHMIC EVENTS WITH MAGNETIC FIELD IMAGING AND QRS-FRAGMENTATION BEFORE ICD IMPLANTATION

*M. Goernig, **D. Di Pietro Paolo, *H.R. Figulla, ***S.N. Erne *Dept. of Cardiology, Universitätsklinikum, Univ. Jena, Jena, Germany **BMDSys GmbH, Jena, Germany ***AB Biosignals, Neurology Clinic, Universitätsklinikimum, Univ. Jena, Jena, Germany

Introduction: Recommendations for ICD implantation in primary prevention of sudden cardiac death in ischemic and non-ischemic cardiomyopathy patients are largely based on ejection fraction. Magnetic field imaging (MFI) is an entirely passive, non invasive, non stressing diagnostic method that could potentially detect high risk population for arrhythmic events with QRS-fragmentation for a more effective ICD therapy.

Methods: MFIs were recorded for 3 minutes at the Biomagnetic Centre of the University of Jena in 13 patients with ischemic and non ischemic heart diseases and EF < 30%. Over 2 years, ICD was controlled every 3 months. MFIs were also recorded for methodological testing in line with the same protocol on several patients with post-intervention metallic contamination.

Results and Conclusions: QRS fragmentation could be performed in all patients, even in the presence of artefacts induced by metallic contamination. In two out of 13 patients a high risk profile in QRS fragmentation was observed. In one of these two patients recurrent arrhythmic events were reported over the two-year follow up, which was not observed in any of the low-risk patients.

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6.7 TROPONIN-T RELEASE AFTER SPONTANEOUS OR INDUCED ICD DISCHARGES CORRELATE WITH TWO-YEAR SURVIVAL

*D. Blendea, *M. Blendea, *J. Banker, *C. McPherson *Bridgeport Hospital, Yale University School of Medicine, Bridgeport, USA

Introduction: Cardiac troponin-T (cTnT) elevation has been reported to occur after implantable cardioverter defibrillator(ICD) discharges, but its prognostic significance is unknown.

Methods:We prospectively evaluated whether cTnT elevation occurring after spontaneous and/or induced ICD discharges correlates with subsequent survival. We studied 174 consecutive patients (68 ± 12 years, 32 women): 66 who received spontaneous ICD discharges for tachyarrhythmias and in the remaining cTnT was measured after ICD testing at the time of device implant. Troponin-T was measured 12–24 h after ICD discharge.

Results: During a 1.9 year average follow-up period, 43 patients died. Patients with a post-discharge cTnT level of ≥0.05 ng/ml had worse survival than those with cTnT <0.05 ng/ml (Figure). The significant relationship between elevated cTnT and survival was present after spontaneous or induced ICD shocks. It persisted in Cox multivariate analysis adjusted for total ICD energy delivered, age, sex, left ventricular ejection fraction, and serum creatinine.

Conclusions: Troponin-T release after ICD discharge, even when it occurs following device testing, is not a random event. It is a risky factor regarding mortality that is independent from other common clinical factors that predict survival in such patients.

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6.8 PROGNOSTIC SIGNIFICANCE OF pro BNP TEST IN PATIENTS WITH CHF AND DEVICE THERAPY. HIGH VALUES ARE RELATED TO PROGNOSIS AND ICD DISCHARGES

**C. Felicani, ****E. Moccia, **F. Naccarella, *D. Vasapollo, ***M. Jasonni, **G. Lepera *Medicina Legale, Università di Bologna, Bologna, Italy **Cardiologia Azienda USL, Bologna, Italy ***Cattedra di Diritto, Università di Modena, Modena, Italy ****Medicina Legale Università di Roma, Rome, Italy

Introduction: ProBNP is currently applied in the management and risk stratification of patients with CHF, and in the effectiveness evaluation of device therapy (DT).

Methods: In the SHAPE project, two groups of CHF patients were evaluated: Group A) 160 consecutive non-selected patients, Group B) 19 patients with an ICD.

Results: In Group A, in the 20 patients with a proBNP of more than 2500–3000 pg/ml, we observed 5 episodes of HF and two CD in the following 3 months; in the group with a proBNP value betweeen 2500 and 1500, 4 recurrences of minor CHF. No problems or clinical recurrences were observed below 500 pg/ml of proBNP. In the range between 501 and 1500 pg/ml, all the patients had history of cardiac disease, CHF or abnormal EF%, but no clinical episodes were observed. In Group B, 6/19 with appropriate discharges or ATP treatments were observed with a mean value of proBNP of 2000 ± 560 pg/ml. In one patient with a low proBNP value, severe hypokalemia caused the arrhythmic storm and ICD discharges. Conversely, no discharges were observed in 13/19 with a mean value of 450 ± 550.

Conclusions: Patients, with appropriate DT interventions show higher mean values of proBNP. Thus, patients with unstable CHF, as documented by high blood peptide values, are at high risk of ventricular arrhythmias.

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7. VENTRICULAR ARRHYTHMIAS: CLINICAL ISSUES

7.1 THE IMPORTANCE OF PROARRHYTHMIC EFFECT OF FLECAINIDE IN UNMASKING HEART DISEASE

*K.G. Adamyan, *A.V. Astvatsatryan, *A.L. Chilingaryan, *S.I. Vardanyan, *T.R. Astvatsatryan *Institute of Cardiology, Myocardial Infarction, Yerevan, Armenia

Introduction: It has been shown that the proarrhythmic effect of flecainide (QRS widening on ECG) depends on coronary patency after thrombolysed Q wave myocardial infarction. We hypothesized that QRS widening on ECG (QRSW) with flecainide during treadmill testing (TT) might be a sign of coronary artery disease (CAD).

Methods: Two hundred sixty-six pts (female/male = 81/185, aged 44.7 ± 22.7 years) with chest pain and ambiguous TT after 3–5 days underwent further TT after having taken 400 mg of flecainide per os 2.5 hours before the test. Patients who developed significant QRSW during the TT were considered to be affected by CAD. Coronary angiography was then performed in all pts within 5–21 days by specialists unaware of the study aims.

Results: Seventy-nine patients (29.7%) developed QRSW during TT with flecainide, whereas 187 patients (70.3%) did not. Seventy-four patients (27.8%) had significant stenosis of coronary arteries. Sixty-nine of these patients (93.2%) had QRSW during TT with flecainide and 5 did not (6.8%).

Conclusions: QRS widening with flecainide during TT is a marker of CAD. TT with flecainide may be used to reveal patients with CAD when standard TT fails to make a diagnosis.

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7.2 ARRHYTHMIA PROPENSITY IN PULMONARY ARTERIAL HYPERTENSION

*I. Henkens, *A. Vonk-Noordegraaf, *H. Vliegen, *C. Swenne, *A. Boonstra, *M. Schalij *Leiden University Medical Centre, Dept. of Cardiology, Leiden, The Netherlands VU University Medical Centre, Dept. of Pulmonology, Leiden, The Netherlands

Introduction: Patients with pulmonary arterial hypertension (PAH) often die of sudden cardiac death. Arrhythmia propensity in PAH patients has not been studied.

Methods: ECGs of 65 PAH patients (13 male) at the time of diagnostic right heart catheterization were compared to ECGs of 253 healthy individuals (78 males).

Results: QRS duration and QTc were prolonged in PAH patients (male: 105 ± 10 ms vs. 93 ± 9 ms, and 448 ± 40 ms vs. 395 ± 22 ms; female: 94 ± 15 ms vs. 84 ± 8 ms, and 438 ± 41 ms vs. 407 ± 26 ms, all P < 0.001). Furthermore, PAH patients had lower mean T-wave amplitude (111 μV ± 73 μV vs. 257 μV ± 95 μV, P < 0.001), lower mean T-wave area (36.1 mV ±18.3 mV vs. 74.3 mV ± 25.5 mV, P < 0.001), and higher QRS-T spatial angle (105°± 35° vs. 73°± 26°, P < 0.001).

Conclusions: Patients with pulmonary arterial hypertension show unfavourable changes in QRS duration and QTc duration as well as repolarization abnormalities. Further research is needed to determine the clinical and therapeutic consequences of these findings.

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7.3 PREDICTIVE RELATIONSHIP BETWEEN MEASURES OF HRV AND TROPONIN-T IN HAEMODIALYSIS PATIENTS

*D.A. McGill, *P.E. Hickman, *G. Talaulikar, *J.M. Potter *Departments of Pathology, Renal Medicine and Cardiology at The Canberra Hospital, Canberra, Australia

Introduction: Cardiac mortality is high in chronic renal failure (CRF) patients. Heart rate variability (HRV) is often abnormal in CRF patients, and may be an independent predictor of cardiac death as is elevated troponin-T.

Methods: All haemodialysis patients (n = 29) without clinically documented cardiac disease were selected. TnI was measured on the Roche™ Elecsys 1010. Ambulatory ECG-monitors were performed 24 hrs before and after dialysis to assess HRV.

Results: The highest tertile TnT-group have significantly reduced HRV variables. Significant unvaried correlations exist between TnT levels and the same HRV measures. The strongest correlation is with minimal spectral power (MSP) (r =−0.76). MSP is the main predictor of TnT-levels in a multivariate linear-regression model. ANOVA shows diabetics have significantly higher TnT. Multinomimal regression suggests that diabetes may cause the association. However, significant correlations still exist for the same HRV variables (e.g., MSP Spearman's r =−0.72) with diabetics excluded from the analysis.

Conclusions: A negative predictive association exists between TnT and HRV, independent of diabetes. Given the ability of HRV and TnT levels to predict cardiac mortality, further investigation of the relationship is warranted.

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7.4 TRANSIENT TRIFASCICULAR BLOCK COMPLICATING MYOCARDIAL CONTUSION AFTER BLUNT CHEST TRAUMA

*M. Bortnik, *E. Occhetta, *C. Ruggeri, *P. Marino *Division of Cardiology, Università del Piemonte Orientale, Novara, Italy

Introduction: Blunt chest trauma has been associated with cardiac impulse formation and/or propagation disorders.

Methods and Results: A previously healthy 32-year-old man was admitted to our emergency department after a blunt chest injury following a car collision; a brief loss of consciousness was reported immediately after the accident. ECG showed sinus rhythm, first degree atrio-ventricular block (PR 240 ms), right bundle branch block and left anterior hemiblock. Chest radiography and transthoracic echocardiography were normal. The peak creatine kinase was 1085 U/L and troponin I 1.06 ng/mL. The day after hospitalization, spontaneous reversion of trifascicular block was observed; the patient remained asymptomatic without abnormalities on continuous cardiac monitoring and was discharged three days after hospital admission. Outpatient follow-up one month later showed the absence of atrio-ventricular and intra-ventricular conduction defects at peak heart rate during an exercise treadmill test; no ventricular or supra-ventricular arrhythmias, nor atrio-ventricular or intra-ventricular conduction disturbances were detected during a 24 hour Holter monitoring.

Conclusions: ECG monitoring and biochemical cardiac markers assessment are important to unmask myocardial contusion, diagnosis of which could otherwise be easily missed.

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7.5 HIGH SURVIVAL FROM CARDIAC ARREST IN VENTRICULAR FIBRILLATION: COMPARISON OF TWO TIME PERIODS

*R. White, *T. Bunch, *D. Hankins *Departments of Anesthesiology, Internal Medicine and Emergency Medicine, Mayo Clinic College of Medicine, Rochester, USA

Introduction: To assess the rate of survival from out-of-hospital cardiac arrest in ventricular fibrillation (VF) during two consecutive time periods (1990–1997 and 1998–2006).

Methods: Retrospective analysis of observational prospectively-acquired outcome data in a controlled population setting before (period 1) and after (period 2) transition from high-energy monophasic to low-energy biphasic waveform defibrillation (truncated exponential and rectilinear waveforms).

Results: During period 1, 39% of all VF patients survived neurologically intact discharge; during period 2, 46% survived (p = 0.30). Sustained pulses with shocks (ROSC) were only obtained in 27% in period 1 and 40% in period 2 (p = 0.04). For bystander-witnessed arrests, survival was 44% in period 1 and 52% in period 2 (p = 0.31) and ROSC was 31% and 45%, respectively (p = 0.05).

Conclusions: High survival was observed in both time periods, with a trend towards higher survival in the second period. In period 2, sustained pulses with shocks alone increased with biphasic waveform defibrillation, with no other differences to explain the increase.

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7.6 ASSOCIATION OF BODYWEIGHT WITH TOTAL MORTALITY AND ICD SHOCKS IN VENTRICULAR FIBRILLATION OUT-OF-HOSPITAL CARDIAC ARREST SURVIVORS

*T.J. Bunch, *R.D. White, *F. Lopez-Jimenez, *R.L. Thomas *Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, USA

Introduction: Studies have shown an association between obesity and total mortality in patients with and without coronary artery disease. Less is known regarding the impact of obesity after cardiac arrest. Obese survivors of ventricular fibrillation (VF) out-of-hospital cardiac arrest (OHCA) may have worse outcomes than non-obese patients due to resuscitation challenges, long-term risks of cardiomyopathy and arrhythmia, and associated comorbid disease.

Methods: All patients who presented with a VF OHCA in Rochester, Minnesota, from November 1990-September 2006 were included in the study. Patients were classified by weight (BMI <25, 25–30, >30). ICD shocks for VF/VT were determined by review of subsequent device interrogations.

Results: During the study period, EMS treated 226 patients (age 63.7 ± 13.5) for VF OHCA with an average call-to-shock time of 6.3 ± 1.8 minutes. Ninety nine patients (44%) survived to hospital discharge with neurologic recovery. Of these patients, data to calculate BMI were available in 213 (95%). There was no difference between the relative distribution of body weight between the hospital survivors [<25 (32%), 25–30 (37%), >30 (31%)] and non-survivors [<25 (32%), 25–30 (44%), >30 (28%)], p = 0.711. There was no difference in ICD implantation rates between weight groups (p = 0.251). The patients were followed for an average of 5.8 ± 4.4 years. The overall 5-year survival was 80 ± 5%. 5-year survival was lower in underweight/normal patients (<25, 71% (63–79) compared to the heavier patients (25–30: 88% (82–94), p = 0.001). Malignancy was the most common cause of death in the underweight group. The 5-year survival free of ICD shocks was 61±7% without significant difference in shocks amongst the different weight-based cohorts.

Conclusions: There was no apparent weight-based influence on resuscitation survival after VF OHCA. However, patients who are under to normal weight had a lower long-term survival and represent a high-risk population, primarily due to the risk of non-cardiac diseases such as malignancies.

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7.7 PRELIMINARY EXPERIENCE OF THE IMPLEMENTATION OF AUTOMATED EXTERNAL DEFIBRILLATORS IN A LARGE BOLOGNA CONDOMINIUM

**C. Felicani, †E. Moccia, **F. Naccarella, ††F. Iachetti, *D. Vasapollo, ***M. Jasonni, †††A.H. Wang, ††††L. Sun, ***G. Lepera *Medicina Legale, Università di Bologna, Bologna ; **Cardiologia Azienda USL, Bologna ; ***Cattedra di Diritto, Università di Modena, Modena ; †Medicina Legale Università di Roma, Rome ; ††Telbios Italia ; ††††Università di Perugia, Perugia, Italy †††Università di Pechino, Peking, China

Introduction: The highest incidence of cardiac arrest (CA) has been observed at patients’ homes. Automated external defibrillators (AED) have been implemented in large malls, airports and schools, but not in condominiums.

Methods: In collaboration with Italian Physiocontrol Medtronic, we implemented two AEDs (and one with Leardal) in three buildings of a large Bologna condominium, in which 120 families live.

Results: For two years, we used the AEDs to monitor 5 patients with acute coronary syndrome (ACS), chest pain or dizziness, while waiting for the ambulance, at the patient's house. In 2006, we monitored 2 patients, one with a stroke and one with a total AV block, while waiting for the ambulance. All patients were later transferred to the emergency department for primary PTCA. Recently, in January and May 2006, in both cases, together with the son of one of the patients we took care of subjects suffering from CA. In the first case, the subject experienced CA due to VF. He was adequately monitored and cardioverted according to AED voice information. The second patient suffered from recurrent VT. The patient was defribrillated 14 times. Both patients were later admitted to the hospital and received an ICD implantation.

Conclusions: AED can be easily implemented in a large condominium, where many subjects are ready to take the CPR course and certificate at the local first aid school. A direct telephone connection with the local emergency room should be available, to simultaneously alert the emergency ambulance. Many patients have been successfully monitored for 20 minutes while waiting for an ambulance. CA can be adequately treated by relatives and family members when AED are available close to the patient's house.

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8. HEREDITARY ARRHYTHMOGENIC SYNDROMES

8.1 CARDIAC INVOLVEMENT AND EVOLUTION IN FAMILIAL AMYLOIDOSIS ACCORDING TO MUTATION TYPE

*M.S. Slama, *V. Algalarrondo, *C. Juin, *C. Sebag, *P. Colin, *V. Plante, *L. Sarda-Mantel, *D. Adams, *D. Samuel, *D. Leguludec, *S. Dinanian *Cardiology Department, Hôpital A Beclere, AP-HP, Clamart, France

Introduction: Familial amyloidosis polyneuropathy (FAP) is a dominantly inherited disease caused by mutated transthyretin (TTR). FAP cardiopathy due to amyloid infiltration results in conduction disorders, cardiac denervation, restrictive and hypertrophic cardiomyopathy, and can cause sudden death. Liver transplantation (LT) is the only treatment that improves prognosis. We compared cardiac involvement related to val-met30 TTR mutation and other mutations.

Methods: Among 126 patients with FAP referred for cardiac evaluation before LT, we performed ECG, 24 hours Holter ECG, echocardiography, scintigraphy, haemodynamic and electrophysiological studies.

Results: Before LT, pacemaker (PM) implantation was necessary in 28.6% val-met30 patients and 33.3% others (NS). We followed 46 non-implanted patients during 19 ± 3 months (range 1 to 64) after OLT. An impairment of conduction detected by ECG or repeat EPS resulted in secondary PM implantation only in val-met30 patients (18/39 vs. 0/7 p < 0.05 χ2 test). PM implantation after LT was independent of age and first EPS data. No significant ventricular arrhythmia was detected by 24 h Holter ECG or induced by EPS, in either group.

Conclusions: Patients with val-met30 mutation FAP were younger and had less cardiac amyloid lesions than patients with other mutations when LT was clinically considered in this series. Val-met30 mutation was an independent predictive factor of secondary conduction disorders and should be considered during follow up. No significant ventricular arrhythmia was detected in either group.

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8.2 SEVERE LONG QT PHENOTYPES ASSOCIATED WITH A NOVEL MUTATION OF I313K AT THE CENTRE OF KCNQ1 POTASSIUM CHANNEL PORE

*T. Ikrar, *H. Hanawa, **H. Watanabe, *S. Okada, *S. Komura, ***Y. Aizawa, *M.M. Ramadan, *Y. Hosaka, *M. Kodama, *Y. Aizawa *Division of Cardiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata City, Japan **Division of Clinical Pharmacology, Vanderbilt University School of Medicine, Vanderbilt, USA ***Masonic Medical Research Laboratory, New York, USA

Introduction: We investigated the functional consequences following a mutation of the I313K signature sequence of KCNQ1.

Methods: LQTS genes were screened by direct sequencing in a family with clinical evidence of LQTS. Mutant and/or wild-type KCNQ1 were co-expressed with KCNE1 in COS-7 cells. The site of mutation was confirmed by a three-dimensional computer model. Plasma membrane localization of KCNQ1 was studied by means of confocal fluorescence microscopy, while IKs were recorded with the whole-cell voltage-clamp technique.

Results: Heterozygous I313K mutation in KCNQ1 was identified in 3 affected members, who demonstrated prolonged QTc intervals and repetitive episodes of syncope. A three-dimensional model of KCNQ1 structure revealed that this mutation was exactly located at the center of the channel pore, and involved the change of a neutral amino acid residue into a positively-charged one. The I313K-KCNQ1 expressed in COS-7 cells demonstrated the lack of an electric current, and appeared to be bound to plasma membrane, similar to WT-KCNQ1 expression. Co-expression with WT-KCNQ1 revealed a dominant-negative effect.

Conclusions: A novel I313K mutation at the center of channel pores of KCNQ1 resulted in a marked loss of channel function, with a dominant-negative effect leading to the long QT interval.

 val-met30 mutationother mutationsp
N9036 
age (years)41.6 +− 1.454.1 +− 1.3<0.0001
% males55.6%63.9%ns
interventricular septum (mm)10.68 +− 0.3313.17 +− 0.53<0.0001
posterior wall (mm)9.2+−0.211.2 +− 0.5<0.0001
left ventricular ejection fraction (%)68.4 +− 0.963.5 +− 1.6<0.05
% of pulmonary capillary wedge pressure > 15 mmHg after 500 ml of volumic expension31.755.5<0.05
MIBG cardiac scintigraphy (heart/mediastinum ratio)1.52 +− 0.051.24 +− 0.05<0.05

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Thumbnail image of graphical abstract

Figure. 

8.3 ELECTROCARDIOGRAPHIC TRANSMURAL DISPERSION OF REPOLARIZATION IN PATIENTS WITH INHERITED SHORT QT SYNDROME

*O. Anttonen, *J. Junttila, *H. Väänänen, *H.V. Huikuri, *M. Viitasalo *Department of Cardiology, Päijät-Häme Central Hospital, Lahti, Finland Department of Internal Medicine, University of Oulu, Oulu, Finland Department of Cardiology, University of Helsinki, Helsinki, Finland

Introduction: Short QT syndrome carries an increased risk of sudden cardiac death. However, not all patients are susceptible to ventricular arrhythmias, necessitating preferably non-invasive methods for risk stratification. In experimental models it has been shown that increased left ventricle wall transmural dispersion of repolarization (TDR) facilitates induction of polymorphic ventricular tachycardia. Therefore, TDR or T-wave peak to T-wave end interval (TPE) and TPE/QT ratio might serve as an index for the risk of pmVT in the SQTS.

Methods: We compared the behavior of the electrocardiographic analogue of TDR in three SQTS patients (18, 52 and 82 years, all HERG negative) with serious ventricular arrhythmias to their nine healthy age matched controls. We hypothesized that the TPE/QT ratio would be greater in SQTS patients than in control subjects. All individuals underwent 24 hour ECG recording and data was transferred to a PC for further analysis of the QT and TPE intervals. All QT peak, QT end and TPE intervals were computed from the recording using the method prescribed earlier by the study group.

Results: As shown in the figure, TPE/QT ratio remained high in all sub-ranges of heart rates, in opposition to the control population. These results may in part explain the increased vulnerability of SQTS patients to ventricular arrhythmias as suggested in experimental models. Quinidine did not lead TPE/QT ratio towards a favourable direction.

Conclusions: TPE/QT ratio seems to be altered in SQTS patients with high risk for serious ventricular arrhythmias and cautious use of Quinidine is advised, at least in patients who do not show mutation in HERG channel.

image

Figure. 

8.4 TWO CASES OF SHORT QT INTERVAL

*M. Moriya, *S. Seto, *K. Yano, *M. Akahoshi *Department of Cardiovascular Medicine, Course of Medical and Dental Sciences, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan

Introduction: The epidemiology of short QT interval remains unclear. We attempted to determine the incidence and clinical characteristics of short QT interval in a longitudinal cohort study.

Methods: A total of 17,361 subjects (6,663 male, 10,698 female) were enrolled in the study and all available electrocardiog rams (ECGs) were investigated longitudinally from 1958 to 2003. We defined short QT interval as QTc of less than 350 ms.

Results: Two met the criteria of short QT interval. Prevalence was 0.01% and incidence was 0.44/100,000 person-years. Case one was a 74-year-old female (height 142.5 cm) with history of ischemic heart disease who died three years later from heart failure. Case two was a 60-year-old male (height 148.2 cm) who exhibited a short QT interval for the first time when he was 26 years old. He had sick sinus syndrome as an underlying heart disease.

Conclusions: No cases were identified as having short QT syndrome with the associated risk of ventricular tachyarrhythmia. There were two short QT interval cases. These observations suggest a clinical relationship between short QT interval, organic or electrophysiological heart disease, and short stature.

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8.5 RECURRENT VENTRICULAR FIBRILLATION TRIGGERED BY INCREASED VAGAL ACTIVITY IN PATIENTS WITH BRUGADA SYNDROME

*M. Swissa, *O. Paz, *A. Caspi *Kaplan Medical Center, Rehovot, Israel

Introduction: Induction of ventricular fibrillation triggered by increased vagal activity and short coupling interval premature ventricular capture (PVC) in patients with Brugada syndrome is presented.

Methods and Results: A 42-year-old patient experienced two consecutive syncope episodes. A syncope episode was noted after urination at midnight. A CPR was immediately initiated. A few minutes later he had the second syncope episode, which resolved spontaneously. An ECG showed slow atrial fibrillation with short coupling interval PVCs. ECG in sinus rhythm was compatible with II pattern Brugada type (Figure 1). All others ECGs were normal. The patient evaluation includes: normal echocardiography, normal exercise test and 320 very short coupling interval PVCs on a 24-hour Holter monitor. Flecainide test was positive. Tilt table test showed postural orthostatic tachycardia syndrome (POTS). Very aggressive electrophysiologic study revealed HV interval of 60 ms and was non-inducible for ventricular arrhythmia with very aggressive protocol. Based on the spontaneous Brugada at the first ECG recording and very short coupling interval VPBs an AICD was implanted. Two weeks later, the patient experienced two appropriate electrical shocks (5 hours separated the 2 episodes) (Figure 2). A clear vagal trigger was noted and short coupling intervals PVC initiated the VF. Quinidine (1500 mg/day) therapy was initiated. The patient has been free of ventricular arrhythmia for more than 2 years.

Conclusions: A clear vagal trigger for VF in patients with Brugada syndrome is presented. Increased vagal tone can induce overt Brugada signs on ECG and may induce a very short coupling interval PVC leading to VF. Quinidine therapy may prevent the ventricular arrhythmias.

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8.6 CLINICAL PROFILE AND FOLLOW-UP OF PATENTS WITH NO STRUCTURAL HEART DISEASE AND IMPLANTABLE CARDIOVERTER DEFIBRILLATOR

*M. Fonseca, *V. Enes, *R. Lima, *D. Caeiro, *L. Adão, *H. Gonçalves, *J. Primo, *R. Rosas, *V. Gama Ribeiro *Department of Cardiology, Vila Nova de Gaia Medical Center, Vila Nova de Gaia, Portugal

Introduction: Our aim was to study the clinical profile of patients with no organic heart disease with criteria for implantable cardioverter defribillator (ICD).

Methods: Retrospective analysis of 8 patients with idiopathic tachyarrhythmias whose initial ICDs were implanted between January 1998 and June 2006. Their clinical history, ancillary examinations and data from the 4-year follow-up examinations were analyzed.

Results: All the patients were survivors of cardiac arrest and underwent complementary examinations (basal electrocardiogram, echocardiogram and coronary catheterisation) which showed no abnormalities. All the patients were male, and the mean age at clinical presentation was 48 years. The electrophysiological study did not induce any arrhythmia in 2 patients; monomorphic ventricular tachycardia (VT) was induced in 63%. All the patients had single-chamber ICDs. Fifty per cent are on beta-blocker therapy and 25% on amiodarone. During the follow-up examinations, half the patients presented no arrhythmic events; the others had between 1 and 18 shocks due to VT, all appropriate. A quarter of the patients had some periods of non-sustained VT. None of the patients died.

Conclusions: It is recognized that, despite careful evaluation, life-threatening arrhythmias can occur with no identifiable causal factor. Patients with documented arrhythmic events must be referred for ICD implantation, even in the absence of a demonstrable structural heart disease, and regardless of the pharmacological treatment.

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8.7 IMPLANTABLE CARDIOVERTER DEFIBRILLATOR IN ARRHYTHMOGENIC RIGHT VENTRICULAR DYSPLASIA: EXPERIENCE OF A PORTUGUESE CENTRAL HOSPITAL

*M. Fonseca, *V. Enes, *R. Lima, *D. Caeiro, *L. Adão, *H. Gonçalves, *J. Primo, *R. Rosas, *V. Gama Ribeiro *Department of Cardiology, Vila Nova de Gaia Medical Center, Vila Nova de Gaia, Portugal

Introduction: Our objective was to study the clinical profile of patients with arrhythmogenic right ventricular dysplasia (ARVD) with criteria for implantable cardioverter defribillator (ICD) in a cardiovascular referral center.

Methods: Retrospective study of 6 ARVD cases diagnosed in our hospital between January 1998 and December 2001 referred for ICD implantation. Their clinical history and echocardiographic, electrophysiologic, cardiac catheterization, and magnetic resonance imaging (MRI) results were analyzed. The mean duration of follow-up was 5 years.

Results: Four patients were male. The mean age at presentation was 40 years. The initial manifestation of the disease was ventricular tachycardia. The basal electrocardiograms showed inverted T waves in the right precordial leads and right bundle-branch block in 67%. Ventricular tachycardia with morphologic features of left bundle-branch block was inducible in 83%. Echocardiography revealed right ventricular enlargement in 4 patients; one presented left ventricular dysfunction. The coronary arteries were normal. The diagnosis was made by means of MRI. During the follow-up period, the youngest patient died during cardiomyoplasty. The remaining patients are currently receiving antiarrhythmic agents; two of them have not had any shock delivered by the ICD and 2 have had multiple episodes of ventricular tachycardia. Two of the patients developed left ventricular dysfunction and heart failure symptoms, one of whom successfully underwent RV cardiomyoplasty.

Conclusions: ARVD is quite a rare disease and represents a small percentage of the indications for ICD, most for secondary prevention purposes. The demographic characteristics of the patients are diverse, although the clinical manifestations and ancillary examination results seem very similar.

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Monday, October 8, 2007

9. ACCESSORY PATHWAYS AND ATRIAL FLUTTER

9.1 INDIVIDUAL IMPACT OF ANATOMICAL AND ELECTROPHYSIOLOGICAL FACTORS IN THE OUTCOME OF RADIOFREQUENCY ABLATION OF ACCESSORY PATHWAYS IN PATIENTS WITH EBSTEIN'S ANOMALY: A SINGLE CENTRE EXPERIENCE

*N. Namboodiri, *S.K. Dora, *S. Bohora, *A. Kumar *V. K., *J.A. Tharakan *Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India

Introduction: The individual impact of various anatomical and electrophysiological characteristics in the procedural outcome of radiofrequency ablation (RFA) of accessory pathways (AP) in patients with Ebstein's anomaly (EA) of tricuspid valve has not yet been studied.

Methods: Twelve patients with EA and history of palpitation, aged 14–37 (mean 23 ± 6.8) years underwent an electrophysiological study with intention of RFA in our institute between January 2001 and December 2006. All of them had manifest preexcitation, while nine (67%) had documented supraventricular tachycardia, including atrial fibrillation in two patients.

Results: The degree of tricuspid regurgitation (DOTR, mean 2.1 ± 0.6, range 0–4), the degree of displacement of septal leaflet (DDSL, mean 26 ± 7 mm), the location of AP (total of 16 APs; six right lateral, six right posterior, three right septal and one left-sided concealed-bypass tract) and presence of fractionated local electrograms (FLE) at tricuspid annulus were assessed in all. Four (33%) had two APs each. In nine (75%) patients, all APs could be abolished by RFA. Of the nine APs in seven patients with FLE, only six APs (in five patients) could be successfully ablated. In four patients with normal local electrograms, all six APs could be successfully ablated. Ablation was not attempted in one patient with single parahisian AP. The presence of FLE, DOTR and DDSL showed a negative correlation with successful outcome while location of AP did not predict the outcome. Among all variables studied, the absence of FLE was the most important predictor of the successful outcome. During 44 ± 15 months of clinical follow-up, one patient with successful RFA had recurrence of AP which was later ablated.

Conclusions: In patients with EA, absence of FLE at tricuspid annulus was the most important predictor of successful RFA. DOTR and DDSL predict procedural outcome in these patients, whereas location of AP does not.

Abstract

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9.2 ABLATION OF LEFT ACCESSORY PATHWAYS USING RETROGRADE AORTIC APPROACH BY NIOBE MAGNETIC NAVIGATION SYSTEM

*A.V. Ardashev, *E.G. Zhelyakov, *A.A. Shavarov, *A.V. Konev, *M.S. Rybachenko *Burdenko Head Clinical Hospital, Moscow, Russia

Introduction: The purpose is to evaluate the feasibility of retrograde aortic approach for radiofrequency catheter ablation (RFA) of left accessory pathways (APs) using NIOBE magnetic navigation system.

Methods and Results: The study was conducted on 10 consecutive patients (pts) (four women, 34.3 ± 13.6 years of age) with the apparent (seven pts) and concealed left-sided APs that were verified during electrophysiology study (left lateral APs in eight cases, left anterior-lateral in two cases). Magnetic 4-mm tip, catheter Helios was passed through aortic valve and advanced to the target positions (atrial (eight cases) and ventricular (two cases) insertion sites of AP) guided by using the X-ray examination and magnetic NIOBE system. Three step maneuver was used for catheter advancement through aortic valve: First step – catheter was advanced to aortic valve into aortic root using motor drive; second step – tip of catheter was positioned near right coronary artery ostium using uniform magnetic field; and third step – catheter was passed through aortic valve guided by catheter advancer system (Cardiodrive) while curved by itself. These maneuvers were successful in all cases (10 pts). RFA was performed (50°C, maximum 50 W, mean duration 20 ± 8 s) in all cases. There were no complications associated with catheter advancement through aortic valve and RFA.

Conclusions: Retrograde aortic approach using NIOBE magnetic navigation system is a safe and feasible technique for advancement of mapping catheter towards either left atrium or left ventricle.

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9.3 CATHETER ABLATION OF AN ATRIOVENTRICULAR BYPASS TRACT CONNECTING A FUNNEL-SHAPED ACCESSORY LOBE OF THE LEFT ATRIAL APPENDAGE WITH THE LEFT VENTRICULAR FREE WALL

*H. Servatius, *T. Rostock, *D. Steven, *B. Lutomsky, *I. Drewitz, *H. Klemm, *R. Ventura, *T. Meinertz, *S. Willems *Cardiology Department, University Heart Centre, Hamburg-Eppendorf, Germany

Introduction: Atrioventricular bypass tracts originating from the right atrial appendage (RAA) with a right ventricular insertion have been described in a few case reports. However, only a single case is reported of an accessory pathway (AP) connecting the left atrial appendage (LAA) with the left ventricle which was treated by surgical separation of the LAA after unsuccessful catheter ablation.

Methods and Results: We report a 68-year old female patient with a history of supra-ventricular tachycardia referred for interventional treatment. Electrophysiological study revealed normal anti-grade conduction via the AV node. Right ventricular (RV) pacing and orthodromic atrioventricular re-entrant tachycardia (AVRT) demonstrated an eccentric retrograde activation pattern with the earliest atrial activity recorded at the distal coronary sinus (CS) catheter placed in a persistent left upper caval vein (LUCV). The posterior mitral annulus was mapped accordingly via a transeptal approach using an irrigated-tip catheter. The earliest atrial activation at the annulus was detected at a post-superior position. Several RF applications at that site did not eliminate the AP and epicardial mapping was continued within the distal LUCV. However, RF applications did not affect the AP despite a similar precocity. Further mapping at the endocardial atrial aspect revealed the earliest retrograde activity within the LAA. Selective angiography and post-procedure computer tomography of the LAA demonstrated a funnel-shaped accessory lobe capping the left ventricular free wall. RF application within this lobe titrated up to 30 W during RV pacing led to sustained elimination of the AP.

Conclusions: This case emphasizes that epicardial APs can insert into the LAA with unusual anatomical characteristics. Therefore, mapping has to include the LAA in order to eliminate AP conduction in this rare setting. To the best of our knowledge, this is the first case reporting on a successful catheter ablation of an AP connecting the LAA with the left ventricle.

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9.4 PARTIAL SPECTRAL ANALYSIS OF ATRIAL ELECTRICAL ACTIVITY IN AF AND ATRIAL FLUTTER

*P. Larsen, *A.M. Stevenson, *N. Lever *Department of Surgery and Anaesthesia, Wellington School of Medicine and Cardiology Department, Auckland, New Zealand

Introduction: We used partial spectral analysis, a mathematical approach that removes the portion of the power spectrum from one signal that is linearly related to that of a second signal, to examine the relationship between electrogram recordings from patients in AF or atrial flutter.

Methods: Simultaneous 80-s electrograms were recorded from multiple sites within the coronary sinus and the pulmonary vein region of the left atria in patients in AF or atrial flutter.

Results: The autospectra from different atrial sites were highly correlated in atrial flutter, such that partialisation of one signal by another resulted in almost complete removal of power within the 0–25 Hz range. In contrast, autospectra from electrograms recorded in AF were largely uncorrelated, with partialisation removing little power, even when a pair of signals had autospectra that appeared to be highly similar, or were from sites physically close to each other.

Conclusions: In AF we found the frequency composition of the electrograms to be highly uncorrelated, implying that they may be the result of distinct wave-fronts of activation, even when the autospectra appear visually to be similar.

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9.5 PROLONGED TRANSIENT ATRIAL ELECTRICAL SILENCE FOLLOWING TERMINATION OF ATRIAL TACHYARRHYTHMIAS (AT)

*C. Saponieri, *D. Benson, *N. El-Sherif, *G. Turitto *The State University of New York Health Science Center at Brooklyn, New York, USA

Introduction: Atrial standstill is a rare heterogeneous arrhythmia, characterized by electrical and mechanical standstill and electrical inexcitability. A progressive form is seen with cardiac and neuromuscular diseases, and a familial form is due to coinheritance of a SCN5A mutation and connexin40 polymorphism. A transient form is associated with drug intoxication, electrolyte imbalance, inflammation, ischaemia, and post-operative states.

Methods: We investigated 3 patients manifesting prolonged transient atrial electrical silence, following termination of AT, without any reversible causes.

Results: All patients underwent AT ablation (flutter in 2 and ectopic AT in 1), with mapping of right and left atria. Atrial electrical silence was observed when, after AT termination, a junctional escape rhythm showed transient (<35 seconds) VA block. A dominant sinus rhythm returned after 30–90 minutes in 2 patients and later in the third.

Conclusions: These cases suggest that chronic overdrive of sinus and secondary atrial pacemakers may result in calcium overloading of cardiac cells, which is known to lead to increased intracellular resistance and prolonged sinus and atrial pacemaker exit block.

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9.6 TRANSOESOPHAGEAL PACING AS ATRIAL FLUTTER TREATMENT METHOD

*M. Vikmane, *O. Kalejs, *K. Jubele, *S. Sakne, *I. Zakke, *A. Maca, *J. Jirgensons, *A. Erglis *P. Stradins University Hospital, Latvian Center of Cardiology, Riga, Latvia

Introduction: The aim of this study was to establish the optimal pacing method to treat patients with paroxysmal atrial flutter [PAF]. To this purpose, six hundred and ten pts with PAF less than 7 days were included into the study between 2002 and 2006.

Methods: Transoesophageal pacing (TEP) was used in all pts to interrupt PAF. Pts were divided into two groups according to selected pacing modality: in group 1 (310 pts) ramp mode was used (3 to 5 impulses with stepwise decrements of 10 msec); in group 2 (300 pts) burst mode was used (25 to 30 impulses). TEP was performed in intensive care unit in all cases within the first 30 mins after the beginning of PAF.

Results: Group 1: in 220 pts (70.9%) sinus rhythm (SR) was immediately restored by TEP, whereas in 58 pts short (10 sec to 120 sec) AF episodes were observed before sinus rhythm restoration and in 32 pts PAF changed to fast atrial tachycardia. Group 2: in 159 pts (53%) SR was immediately restored by TEP, whereas in 140 pts fast atrial tachycardia was observed, which then converted into SR in 85 pts; in 55 pts PAF degenerated into AF.

Conclusions: 1. TEP is an effective therapeutical option to treat PAF 2. Ramp pacing mode seems to outclass burst pacing mode.

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9.7 COMPARISON OF CONVENTIONAL WITH MINIMAL CATHETER APPROACHES FOR THE MAPPING AND ABLATION OF CARDIAC ARRHYTHMIAS: A RANDOMIZED CONTROLLED TRIAL

*R. Liew, *S. Harris, *K. Rajappan, *D. Gupta, *V. Wadhera, *G. Thomas, *C. Redpath, *V. Mullan, *L. Richmond, *A. Nathan, *M. Earley, *S. Sporton, *R. Schilling *Department of Cardiology, St Bartholomew's Hospital, London, UK

Introduction: We investigated the use of minimal diagnostic catheters for ablation of regular SVTs by comparing this to a conventional approach in a randomized controlled trial.

Methods and Results: Ninety-five patients had catheter ablation of SVTs (excluding atrial tachycardia) using minimal, MIN, (2 catheters for atrial flutter, 3 for other SVTs), or conventional catheters, CON, (3 and 5 catheters respectively). Acute procedural success was similar. There were no significant differences in procedure time (95.2 ± 6.1 vs. 100.9 ± 6.6 mins, mean ± SEM), screening time (21.6 ± 2.2 vs. 23.7 ± 3.1 mins) or radiation dose (1626 ± 328 vs. 2737 ± 879 cGycm2) between the two groups (MIN and CON). The MIN group used fewer catheters (2.8 ± 0.1 vs. 4.5 ± 0.1, p < 0.0001) and was cheaper (7.9 ± 0.6 vs. 10.6 ± 0.6 units, p < 0.01; one unit being the cost of a standard quadripolar catheter). Complications included one complete heart block (MIN) and one transient second degree block (CON).

Conclusions: Use of a minimal catheter in the treatment of SVTs is effective, quick and safe as using a conventional number and is cheaper.

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10. ATRIAL FIBRILLATION: CLINICAL ASPECTS

10.1 CLINICAL SIGNIFICANCE OF DYNAMIC INTERATRIAL CONDUCTION THRESHOLD IN DETECTING ATRIAL VULNERABILITY

*D. Cozma, *C. Luca, *L. Petrescu, *S. Pescariu, *N. Radoi, *S.I. Dragulescu *Institute of Cardiovascular Medicine, Timisoara, Romania

Introduction: The aim of this study is to assess the role of dynamic interatrial conduction time (iaCT) in the onset of atrial fibrillation AF.

Methods: One hundred and twelve consecutive patients (pts) aged 43 ± 16 years referred for electrophysiologic study (EPS) were included. To examine atrial electrophysiologic properties iaCT behaviour was studied and decreasing index (DI) was calculated as previously described as maximal percentage prolongation of iaCT during atrial extra-stimulation. Left atrial (LA) surface (LAS) was measured at end-systole (maximal). Trapezoidal LA shape was defined if transverse dimension < basal dimension.

Results: iaCT ranged 42–87 ms; DI ranged 4–111%. Baseline iaCT and DI were significantly prolonged in pts with, compared to pts without AF (iaCTb: 69.4 ± 26 ms vs. 55.6 ± 19 ms, p = 0.01, DI: 51.5 ± 19.5% vs. 29.6 ± 15.6%, p < 0.0001). Inducible episodes of paroxysmal AF during EPS using programmed atrial stimulation were demonstrated in 32 pts (28%). Minimal prolongation of iaCT to induce AF was 177 ms. Using LAS>25 cm2 as a cut-off value, LA vulnerability to AF can be detected with a sensitivity of 56.2% and a specificity of 95%. Trapezoidal LA shape was found in 72% pts with LAS > 25 cm2.

Conclusions: This study supports the role of dynamic interatrial conduction disturbances and threshold in the genesis of AF. LA shape and size remodelling may be the cause and substrate of decreasing conduction properties which may lead to inducible episodes of AF.

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10.2 ATRIAL FIBRILLATION (AF) IN CHRONIC HEART FAILURE (CHF): THE BOLOGNA REGISTRY OF THE INTERNATIONAL AF-CHF STUDY

**C. Felicani, †E. Moccia, **F. Naccarella, ††F. Iachetti, *D. Vasapollo, ***M. Jasonni, †††A.H. Wang, ††††L. Sun, **G. Lepera *Medicina Legale, Università di Bologna, Bologna ; **Cardiologia Azienda USL, Bologna ; ***Cattedra di Diritto, Università di Modena, Modena ; †Medicina Legale Università di Roma, Rome ; ††Telbios Italia ; ††††Università di Perugia, Perugia, Italy †††Università di Pechino, Peking, China

Introduction: Atrial fibrillation and chronic heart failure are recognized as major epidemics in the 21st century. The treatment of AF in CHF patients remains to be determined.

Methods: We enrolled 40 consecutive pts in the Bologna registry, similarly to the Canadian AF-CHF study. The patients were randomly assigned to the two therapeutical strategies (TS) for AF in CHF patients: rhythm control (RHYC) or rate control (RAC). Clinical features, associated TS and prognosis are reported.

Results: Etiology was CAD (55%), followed by DCM (15%), and valvular diseases (12.5%). 21/40 pts were randomized to RHYC and 19/40 pts to RAC. EF% was 30% in the entire group, and 31% and 28% in the RHYC and RAC groups, respectively. The majority of pts were in NYHA class 3 (57.5%) and NYHA class 4 (22.5%). B-blockers and ACEi were administered in 85% and 82% pts in both groups. Electrical ablation (EA), pacing or CRT, CABG and valvular operations were more frequently undertaken in RHYC than RAC. The 1-year prognosis showed a significantly higher mortality in RAC: 6/19 (39.5%) versus RHYC 2/21 (9.5%). Only 9/21 (42.8%) in RHYC were in SR, as against 0/19 in RAC. 38/40 received OAT.

Conclusions: CHF patients with AF are characterized by severely reduced EF and advanced NYHA classes. Optimal drug therapy should be instituted, including non-anti-arrhythmic agents and OAT. Of the two available therapeutical strategies, RHYC is justified in patients in whom AF is associated with severe hemodynamic deterioration. Frequently, non-pharmacological treatment, including cardiac surgery (CS) and/or EA needs to be applied in order to maintain SR. Conversely, RAC should be used when AF is not clearly associated with a worsening of CHF symptoms. On applying these guidelines, including CS and/or EA, RHYC seems to be superior to RAC in the long-term prognosis of AF-CHF patients.

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10.3 HEART FAILURE MORTALITY AND SUDDEN DEATH MORTALITY IN THE BOLOGNA DATABASE OF THE EURO HEART SURVEY ON CHRONIC HEART FAILURE II

**C. Felicani, †E. Moccia, **F. Naccarella, ††F. Iachetti, *D. Vasapollo, ***M. Jasonni, †††A.H. Wang, ††††L. Sun, **G. Lepera *Medicina Legale, Università di Bologna, Bologna ; **Cardiologia Azienda USL, Bologna ; ***Cattedra di Diritto, Università di Modena, Modena ; †Medicina Legale Università di Roma, Rome ; ††Telbios Italia ; ††††Università di Perugia, Perugia, Italy †††Università di Pechino, Peking, China

Introduction: Acutely decompensated heart failure (ADHF) patients were enrolled in the EURO HEART FAILURE SURVEY II (EHFII). They had a severe prognosis on discharge and during follow-up (FU).

Methods and results: In EHFII, 60 patients were enrolled in Bologna. The clinical characteristics of these patients and the occurrence of heart failure death (HFD) and sudden death (SD) was evaluated during 3–6–12-month FU. Twenty-eight per cent suffered a new episode of ADHF, while 72% were decompensated CHF patients. 63% had acute pulmonary edema. The mean age was 77.0, and 51% were males. Cardiomegaly was documented in 83%. Thirty showed concomitant renal failure, and diabetes was present in 20. Fifty-eight per cent underwent cardiac catheterization and coronary arteriography. 10% were on permanent pacing and CRT, and 3% already had an ICD. Almost 100% were already on diuretic agents, 62% on ACEi, 88% on beta-blockers. Fifteen patients had an ACS as the cause of ADHF; the remaining 45/60 were patients with an already known CHF. The best non-pharmacological treatment (NPT) was instituted; 4 patients underwent CRT treatment, and another two ICD therapy. On discharge, we lost 10/60 patients, mainly as a result of ACS; at 3 months, we lost another 7 patients, and at 6 months another 8 patients. We lost 26/60 (43.3%) of the patients. During 12 months’ FU, 3 SD were observed (5.2%) + 2 appropriate ICD shocks (15%).

Conclusions: ADHF bears an ominous prognosis, mainly for patients with already documented CHF and for patients suffering ACS. More aggressive treatment, including primary PTCA and CABG or cardiac surgery, when indicated, is required. For CHF with a new ADHF episode, a further approach, with an NPT may be required, after stabilisation of the clinical picture.

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10.4 LEFT ATRIAL FRUSTUM VOLUME IN PATIENTS WITH PAROXYSMAL ATRIAL FIBRILLATION

*D. Cozma, *C. Luca, *L. Petrescu, *C. Mornos, *S.I. Dragulescu *Institute of Cardiovascular Medicine, Timisoara, Romania

Introduction: We hypothesized that the underestimation of real left atrial (LA) volume by means of the ellipse model in patients (pts) with atrial fibrillation (AF) may be explained by a different pattern of dilatation.

Methods: Sixty-eight pts aged 51 ± 17 years with paroxysmal AF were included. Parameters: LA dimensions (LAd = M-mode, parasternal long axis, LAt and LAl are the measurements of short- and long-axis apical four-chamber view), and LA surface (LAS). Two new measurements were introduced: basal and annular dimension of LA (LAb/LAa) this latter being the maximal transverse distance at the base/mitral annulus of the LA in the apical four-chamber view. LA measurements were calculated at end-systole (maximal). Trapezoidal LA shape was defined as transverse dimension < basal dimension. LAv was calculated using both the ellipse formula π/6 (LAdxLAlxLAt) and the truncated-cone (frustum) formula πLAl/12(LAa2+ LAb2+ LAa × LAb).

Results: LAS ranged from 16.5 to 34.5 cm2. Trapezoidal LA was found in 48 pts. LAS was 18 ± 2.7 cm2 in pts with ellipsoidal shape and 24.5 ± 6.5 cm2 in patients with trapezoidal shape (p < 0.0001). In the subgroup with ellipsoidal shape, LAv was 47.7 ± 6.7 cm3(using the ellipse formula) and 51.5 ± 7.8 cm3 (using the truncated-cone formula, p = 0.08). In the subgroup with trapezoidal shape, LAv was 62.3 ± 8.6 cm3 (ellipse formula) and 87.3 ± 15.7 cm3 (truncated-cone formula, p < 0.0001). Trapezoidal LA with atrialization of the pulmonary veins and predominant dilatation of the basal atrium rather than the annular side may explain underestimation of LA volume by means of the ellipse formula.

Conclusions: Complete characterization of LA remodeling in patients with AF should include shape definition and LAb, and LAS (a parameter independent of geometrical assumption); LAv calculation by means of the truncated-cone formula may be more accurate.

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10.5 THE 2D SINGLE-PLANE VOLUME IS A SIMPLE AND ACCURATE ESTIMATE OF ACTUAL LEFT ATRIAL SIZE. A 3D ECHO STUDY

*R. Marinigh, *L.P. Badano, *N. Pezzutto, *M. Cinello, *D. Pavoni, *P. Gianfagna, *P.M. Fioretti *Department of Cardiopulmonary Sciences, Azienda Ospedaliero-Universitaria “S Maria della Misericordia”, Udine, Italy

Introduction: Left atrial (LA) size has shown prognostic importance in several valvular and arrhythmogenic conditions. Various M-mode and 2D echocardiography approaches are used to estimate LA size. However, M-mode and 2D measures of LA size rely on various geometrical assumptions and their accuracy remains to be determined.

Methods: Routine LA dimensions at end-systole were obtained in 85 patients (58% males, 63 ± 15 years, range 22 to 87). All these measurements were compared with LA end-systolic volume (LAV) obtained by means of a real-time multi-plane 3D method.

Results: The mean 3D LAV was 88 ± 62 ml (range 24–458). Correlations with various M-mode and 2D measurements are reported in the table.

3D LA Volume vs.r95% CI for rp Value
2D 4-chamber LA Sup-In Diam. (cm)0.700.57–0.79<0.0001
M-mode LA Diam. (cm)0.760.65–0.84<0.0001
2D 4-chamber LA Medio-Lat Diam. (cm)0.860.79–0.90<0.0001
2D 4-Chamber LA Area (cm2)0.920.88–0.96<0.0001
2D 4-Chamber LA Volume (ml)0.980.94–0.97<0.0001
2D Biplane LA Volume (ml)0.970.96–0.98<0.0001

Bland-Altman analysis demonstrated a bias of −1.7 ml between 3D and bi-plane 2D LAV (limits of agreement were ± 30 ml), and a bias of −0.4 ml between single-plane 2D LAV and 3D LAV (limits of agreement were ± 35 ml).

Conclusions: Since 2D single-plane 4CH LAV is just as accurate as biplane LAV, and less time-consuming and more feasible than 3D LAV, it may be used in daily clinical practice to assess LA size.

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10.6 A STATISTICAL ANALYSIS OF FACTORS RELATED TO ATRIAL FIBRILLATION RECURRENCE IN A POPULATION OF 47 PATIENTS WHO UNDERWENT ELECTRICAL CARDIOVERSION

*L. Santini, *L.P. Papavasileiou, *A. Panella, *V. Romano, *M. Sgueglia, *G. Magliano, *M. Vellini, *M. Borzi, *F. Romeo *Department of Cardiology, Policlinico Tor Vergata, Rome, Italy

Introduction: The efficacy of electrical cardioversion in restoring sinus rhythm (SR) in atrial fibrillation (AF) patients is extremely effective but is limited by a high number of arrhythmia recurrences within 2 weeks after cardioversion (CV).

Methods: We performed electrical cardioversion (ECV) in 47 consecutive patients from July 2006 to November 2006 (17 female, 30 male, mean age 70.3 ± 6.6 years, left atrium diameter 45.8 ± 5.4 mm, LVEF 56.6 ± 5.4%) affected by persistent atrial fibrillation (mean duration 9.4 ± 15.6 months), 30/47 pts were at the first episode of AF. 37 pts were affected by hypertension, 21 pts presented hypercholesterolaemia, 6 were affected by ischemic heart disease. All patients received effective anticoagulant therapy. The antiarrhythmic treatment was: 7 pts flecainide, 10 propafenone, 11 amiodarone, 12 amiodarone+ flecainide, 5 sotalol and 2 without antiarrhythmic therapy. We evaluated patients at one week after ECV, 1 month, 3 and 6 months. We performed unvaried logistic regression analysis.

Results: One week after successful ECV, 15/47 pts (31.9%) presented AF recurrence. In 8 patients we preferred rate control strategy. In the others 7 pts antiarrhythmic therapy was increased, restoring SR. At the 1-, 3- and 6-month follow ups no patient presented AF recurrence. The statistical analysis showed that the use of AT2 blockers and the presence of I degree AV block are correlated with SR at one week after ECV, whereas duration of arrhythmia, presence of left anterior fascicular block and number of previous AF episodes correlate with AF recurrence.

 PODDS RATIO95% CI
  1. At one, three and six months none of the evaluated parameters resulted to be statistically significant, as there were no AF recurrences.

No. AF0.0540.250.06 ± 1.02
AT20.0350.100.01 ± 0.85*
I° AV block0.0400.220.05 ± 0.93*
LAFB0.0530.120.01 ± 1.02
AF duration0.0571.061.0 ± 1.12

Conclusions: AF recurrence is very high in the first week after ECV (31.9%); it thereafter decreases and becomes more constant over time. The presence at the ECG immediately after successful ECV of I degree AV block is correlated with a low rate of AF recurrence. The use of AT2 blockers as non-antiarrhythmic treatment can help maintain SR. The duration of atrial fibrillation or the presence of left anterior fascicular block is correlated negatively with arrhythmia recurrence. The evaluation of a larger population will help identifying factors related to early and late AF recurrence.

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10.7 ELECTROANATOMIC CHARACTERISTICS OF THE ELECTROPHYSIOLOGIC SUBSTRATE IN PERSISTENT/PERMANENT ATRIAL FIBRILLATION

*E. De Ruvo, *L. Sciarra, *A. Sette, *G. Navone, *F. Nuccio, **T. Di Camillo, *R. Cioè, *A.M. Martino, *G. Carlino, *E. Lioy, *L. Calò *Divisione di Cardiologia, Policlinico Casilino, Rome, Italy **Divisione di Cardiologia, Ospedale Mazzini, Teramo, Italy

Introduction: Complex fractionated electrograms (CFAEs) and rapid atrial activity (RAA) recorded during atrial fibrillation (AF) have been proposed as target sites for catheter ablation in patients with persistent and permanent AF.

Methods: Eighteen patients (4 females; mean age, 59 ± 11 years) with refractory AF (9 persistent, 7 permanent) underwent non-fluoroscopic electroanatomic mapping (CARTO) during AF, before radiofrequency ablation. Areas associated with CFAEs and RAA were identified using a software that enables both types of electrograms to be tagged. In order to improve the accuracy of electroanatomic mapping, the software was customized to recognize: a) atrial electrograms with a very short cycle length and b) atrial electrograms composed of two or more deflections or with continuous activity. The mapping window for each point was performed over a 2.5-second recording period.

Results: The maps were composed of a mean of 116 ± 22 points for the left atrium (LA) and 96 ± 32 points for the right atrium (RA). CFAEs were found in both atria, but were mainly confined to LA septum (94%), LA posterior wall close to the superior pulmonary veins (PVs) (88%), LA floor above the coronary sinus (CS) (83%), RA septum (77%) and CS os (66%). RAA was mainly localized inside and around the pulmonary veins and around and inside the CS os.

Conclusions: AF substrate is an important target in persistent and permanent AF ablation. CARTO with CFAE software allows rapid recognition of the areas in which CFAEs and RAA are represented more.

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11. ATRIAL FIBRILLATION: DRUG THERAPY

11.1 ANALYSIS OF THE MEDICAL CARE OF PATIENTS WITH ATRIAL FIBRILLATION BY LOCAL CARDIOLOGISTS IN THE CZECH REPUBLIC

!*V. Bulkova, **M. Fiala, **J. Chovancik, ***D. Wichterle, **M. Branny, ***J. Kautzner*Faculty of Medicine, Palacky University, Olomouc, Czech Republic**Department of Cardiology, Hospital Podlesi, Trinec, Czech Republic**IKEM, Department of Cardiology, Prague, Czech Republic

Introduction: Retrospective 2-year medical data obtained from local cardiologists were analyzed in 306 patients (pts) (94 F, 64 ± 11 years).

Methods and Results: AF was paroxysmal, persistent and permanent in 141 (46%), 77 (25%), and 88 (29%) pts. Hypertension was present in 220 (72%) pts, and both CAD and DM in 83 (27%) pts respectively. Symptoms were present in 122 (39%) pts. LV ejection fraction (LVEF) was 55 ± 11%, (permanent vs. paroxysmal AF: 51 ± 13 vs. 58 ± 9%, P < 0.001). Left atrial diameter was 47 ± 7 mm. Warfarin was taken by 230 (75%), and ASA by 43 (14%) pts. Antiarrhythmic (AA) drugs were used by 275 (90%) pts; no pt with impaired LVEF was treated with class I AA drugs. Amiodarone-related complications occurred in 24 pts. Electrical cardioversion was performed in 167 (55%) pts. AF-related hospitalization (4.2 ± 3.2 days) was reported in 144 (47%) pts. Embolic complication required 29 hospitalizations (8.2 ± 2.9 days) in 25 (8%) pts. Stroke, TIA, and systemic arterial embolism in other sites were observed in 8, 16, and 5 pts respectively. Heart failure occurred in 13 (4%) pts.

Conclusions: Good quality of medical care, particularly regarding anticoagulation and AA drug use, was found in patients treated by local cardiologists.

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11.2 ANTIARRHYTHMIC DRUGS: EVALUATION OF PRESCRIPTIONS IN ITALY AND THE VENETO REGION IN YEARS 2004–2006

*A. Dorigo, **L. Furlanetto, **F. Zanardi, *N. Burlon, *R. Foffano *Pharmacy Service, Umberto I Hospital, Az. ULSS 12 Veneziana, Venice-Mestre, Italy **Territorial Pharmaceutical Service, Az. ULSS 12 Veneziana, Venice-Mestre, Italy

Introduction: The monitoring of drug prescriptions is very important to estimate the fluctuations of prescriptions and costs. The aim of this study is to monitor the prescriptions of antiarrhythmic drugs in Italy and the Veneto Region; this facilitates the quantification of patients with cardiac arrhythmias in comparison with the whole population.

Methods: The study area is the Veneto Region, with about 4 700 000 inhabitants, and Italy with 58 500 000 inhabitants. Data are obtained from public health data base for the years 2004–2006. Drugs are quantified both as number of prescriptions and defined daily doses per 1000 inhabitants a day (DDD/1000 inhabitants/die), indicators accepted from the World Health Organization.

Results: The DDD/1000 inhabitants/die of antiarrhythmic drugs in Italy (8 800 000 prescriptions) are 7.30, 7.42 and 7.55; in Veneto (870 000 prescriptions) they are 9.07, 9.10 and 9.13, in 2004, 2005 and 2006 respectively. Propafenone is the most consumed – 3.5 average in Italy and 4.25 in Veneto. Prescriptions of Fleicainide are increasing remarkably (Italy:+13.5%; Veneto:+9%).

Conclusions: The total prescriptions of antiarrhythmic drugs are in light increase (Italy: +1.7%; Veneto: +0.4%). Proportionally, there are more patients treated with antiarrhythmics in Veneto (about 0.91% of population) than in Italy (about 0.75%).

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11.3 COMPARING ANTIARRHYTHMIC DRUGS IN PREVENTING ATRIAL FIBRILLATION RECURRENCE

*L.P. Papavasileiou, *L. Santini, *A. Panella, *M. Sgueglia, *L.E. Di Battista, *V. Romano, *G. Magliano, *M. Borzi, *F. Romeo *Cardiology Department, Policlinico Tor Vergata, Rome, Italy

Introduction: The efficacy of electrical cardioversion in restoring sinus rhythm in persistent atrial fibrillation (AF) is limited by a high relapse rate in spite the use of antiarrhythmic therapy. It is reported that in more than one third of cases, AF recurs within 2 weeks after ECV. Thereafter the probability of recurrence decreases and becomes more constant over time.

Methods: We performed electrical cardioversion (ECV) in 65 consecutive patients from July 2006 to November 2006. 14 pts were lost at follow up, the remaining 51 pts (10 female, 41 male, mean age 69 ± 4 years, mean weight 79 ± 4 kg, left atrium diameter 45 ± 4 mm, LVEF 57 ± 5%) were affected by persistent atrial fibrillation (mean duration 12.7 ± 50 months) and hypertension. All patients received effective anticoagulant therapy. The antiarrhythmic treatment was: 8 pts flecainide, 10 propafenone, 12 amiodarone, 15 amiodarone+ flecainide, 3 sotalol and 3 without antiarrhythmic therapy. We evaluated AF recurrence at one week after ECV, 1 month, 3 and 6 months.

Results: At one week after successful ECV 16/51 pts (31%) presented AF recurrence (8 pts on amiodarone treatment, 2 pts on amiodarone and flecainide, 1 pt on sotalol, 1 pt on flecainide, 4 pts on propafenone). In 8 patients we chose rate control strategy. In the 8 pts in treatment with amiodarone, 150 mg/die of flecainide were added restoring sinus rhythm within a week. In the 2 pts on IC drugs the dose of anti-arrhythmic was increased and restored SR in both within a week. The 3-month follow up showed AF recurrence in 2 more pts, one on amiodarone and flecainide and one on sotalol (2/43, 4.6%). The six months follow-up, performed in 37/41 pts, did not show new episodes of AF. Statistical analysis (X2) of the antiarrhythmic treatment one week after ECV showed: amiodarone vs. amiodarone+ flecainide (p = 0.004), amiodarone and flecainide vs. sotalol, propafenone, flecainide (p = ns). At 3 months the combination of amiodarone and flecainide still results superior to amiodarone alone (p = 0.004).

Conclusions: The combination of amiodarone and flecainide proved to be effective and safe and results superior to amiodarone treatment alone both at the 1-week and 3-month follow ups. In our study, adding flecainide in pts on amiodarone treatment and AF recurrence one week after cardioversion was shown to be to be highly effective in restoring and maintaining SR.

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11.4 CANDESARTAN REDUCES VULNERABILITY IN BURST-INDUCED ATRIAL FIBRILLATION AND MYOCARDIAL INTERSTITIAL FIBROSIS IN GOATS

*S.I. Chrysostomakis, *I.K. Karalis, *E.N. Simantirakis, *A.V. Koutsopoulos, *H.E. Mavrakis, *K.G. Parasyri, *P.E. Vardas *Cardiology Department, Heraklion University Hospital, Heraklion, Crete, Greece

Introduction: Using a goat as a model, we tested the hypothesis that candesartan reduces AF induction susceptibility and fibrotic degeneration of both atria and ventricles.

Methods: We examined 3 groups of 5 goats for 6 months. Groups A and B were implanted with a pacemaker capable of burst-maintaining AF. Group A goats were administered candesartan. Group C animals served as controls. Animals were periodically tested for AF induction and vulnerability. At the end of the study, all four heart chambers were examined and fibrosis quantified.

Results: All A and B group goats developed tachy-cardiomyopathy. Although AF vulnerability significantly increased in group B over time (p = 0.045), this was not the case in group A (p = 0.23). Histology revealed a significant increase in fibrous tissue in AF goats, in all four heart chambers, in comparison with controls. Moreover, fibrosis was significantly lower in animals on candesartan.

Conclusions: Our study indicates that candesartan reduces susceptibility to AF in goats and favorably affects atrial structural remodeling. In addition, we demonstrated a beneficial effect of candesartan on tachyarrhythmia-induced ventricular fibrosis.

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11.5 NON-ANTIARRHYTHMIC PHARMACOLOGICAL TREATMENT WITH RAA INHIBITORS HELPS PREVENT THE RECURRENCE OF ATRIAL FIBRILLATION AFTER SUCCESSFUL ELECTRICAL CARDIOVERSION

*A. Panella, *L.P. Papavasileiou, *L. Santini, *V. Romano, *M. Sgueglia, *G. Magliano, *M. Vellini, *M. Borzi, *F. Romeo *Department of Cardiology, Policlinico Tor Vergata, Rome, Italy

Introduction: ACE inhibitors and AT2 blockers have a IIa class of recommendation with a B level of evidence as non-antiarrhythmic pharmacological treatment for prevention of recurrences. Many studies in the literature have shown a lower AF recurrence rate in patients treated with RAA blockers in addition to a traditional antiarrhythmic therapy. Sinus rhythm is hard to be maintained due to the electrical and mechanical modifications of atria that occur during AF.

Methods: We evaluated the efficacy of the therapy with ACE inhibitors or AT2 blockers in addition to traditional antiarrhythmic treatment for the prevention of recurrence of AF six months after successful DCS. Fifty-one consecutive patients (10 female, 41 male, mean age 69 ± 4 years, mean weight 79 ± 4 kg, left atrium diameter 45 ± 4 mm, LVEF 57 ± 5%) affected by persistent atrial fibrillation (mean duration 12.7 ± 50 months) and hypertension underwent an oesophageal electrical cardioversion. All patients were on a proper anticoagulant therapy. Thirteen patients were treated with amiodarone after DCS, 8 patients with flecainide, 15 patients with amiodarone and flecanide, 10 patients with propafenone, 3 patients with sotalolo. Twenty-five patients received ACE inhibitors, 14 AT2 blockers and 12 did not receive any RAA inhibitor. A follow up was performed six months after DCS.

Results: Within 6 months, AF relapsed in 15 patients (28.4%), while SR was still present in 36 patients (71.6%). In the group of patients receiving therapy with ACE inhibitors, 11/25 (44%) had AF, 14/25 patients still were in SR; in the group treated with AT2 blockers,14/14 were in SR. In patients that did not take any RAA system blocker, 4/12 had FA recurrence (33%) while 8 patients (67%) were in SR. X2 test was used to compare data of ACE inhibitors vs. no therapy (p = ns), AT2 blockers vs. no therapy (p = 0.01), AT2 blockers vs. ACE-inhibitors (p = 0.003).

Conclusions: Efficacy of electrical cardioversion is limited by the high rate of AF recurrence despite the use of traditional antiarrhythmic therapy. Non-antiarrhythmic pharmacological treatment with RAA inhibitors helps to prevent the recurrence of atrial fibrillation. In our series, AT2 blockers were shown to be more effective in preventing AF recurrences compared to ACE inhibitors or no therapy.

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11.6 AMBULATORY ELECTRICAL CARDIOVERSION AND PRE-TREATMENT WITH ACE INHIBITORS, ANGIOTENSIN RECEPTORS BLOCKERS AND STATINS IN PATIENTS WITH PERSISTENT ATRIAL FIBRILLATION

*G. Marchetti, *R. Roncuzzi, *P. Grazi, *A. Grepioni, *G. Labanti, *P. Passarelli, *M.A. Ribani, *S. Urbinati *Ospedale Bellaria, Bologna, Italy

Introduction: Rhythm control strategy in atrial fibrillation (AF) can be managed with electrical cardioversion (ECV). In persistent AF less than one third of patients (pts) remain in sinus rhythm (SR) after a one-year follow up. An approach with pre-treatment beta-blockers (BB), Amiodarone (AM), plus Angiotensin Converting Enzyme inhibitors (ACEi) or Angiotensin Receptors Blockers (ARBs) and statins can be applied to improve SR maintenance, repeating ECV in case of symptomatic AF. The aim of our study was to investigate the short- and long-term success rates in restoring SR in unselected pts pre-treated with these agents.

Methods: We conducted an observational study over a year period of 42 consecutive patients (30 males, 12 females) referred to our Day Hospital for ECV of persistent AF. Mean age was 69.9 years. An international normalized ratio of 2–3 was achieved and continued until 1 year of follow up. AF duration was 30–60 days in 4 pts, 60–90 days in 4 and 120 days-2 years in 34 pts. Hypertension was present in 14 pts, ischaemic heart disease in 6 pts, valvular heart disease in 7 pts, “lone” atrial fibrillation in 23 pts. Atrial fibrillation rate (AFR) as an index of remodelling was estimated in V1. ECV was performed with R wave synchronized biphasic direct current shocks, using a step up protocol of 70–100–150 joules in an antero-posterior paddles configuration, under general light anaesthesia. All patients received BB, AM, ARBs or ACEi and statins 1 month before ECV, continuing during follow up. In 4 pts ECV was repeated in the first month for AF recurrence and in 2 pts between the 4th and 6th months.

Results and Conclusions: Rates of maintenance of SR were 90.4% and 62% respectively at 1 month and 1 year. Long atrial fibrillation duration before cardioversion was not a strong predictor of subsequent AF recurrence. A reduction in AF relapse was more evident in pts with left ventricular dysfunction or left ventricular hypertrophy. Adding ARBs or ACEi and statins to amiodarone to prevent AF recurrences is useful in patients with persistent AF through several mechanisms that reverse electrical remodelling (shortening of refractoriness due to the high atrial rate) and inhibit AF induced structural atrial remodelling (fibrosis, myocite hypertrophy and degeneration). An “aggressive” approach repeating early ECV in symptomatic AF is useful for obtaining stable SR at follow up. AFR was indicative of electrical remodelling during the first hours after AF relapse in patients pre-treated with these pharmacological agents.

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12. ATRIAL FIBRILLATION: NONPHARMACOLOGICAL THERAPY

12.1 MANAGEMENT AND RATE OF ATRIAL FIBRILLATION RECURRENCES EARLY AFTER ELECTRICAL CARDIOVERSION

*L.P. Papavasileiou, *A. Panella, *M. Sgueglia, *V. Romano, *M. Di Luozzo, *L. Santini, *G. Magliano, *M. Borzi, *F. Romeo *Department of Cardiology, Policlinico Tor Vergata, Rome, Italy

Introduction: The efficacy of electrical cardioversion in restoring sinus rhythm in persistent atrial fibrillation (AF) is limited by a high relapse rate. It is reported that in more than one third of cases, AF recurs within 2 weeks after ECV. Thereafter the probability of recurrence decreases and becomes more constant over time.

Methods: We performed electrical cardioversion (ECV) in 65 consecutive patients from July 2006 to November 2006. 14 pts were lost at follow-up, the remaining 51 pts (10 female, 41 male, mean age 69 ± 4 years, mean weight 79 ± 4 kg, left atrium diameter 45 ± 4 mm, LVEF 57 ± 5%) were affected by persistent atrial fibrillation (mean duration 12.7 ± 50 months) and hypertension. All patients received effective anticoagulant therapy. The antiarrhythmic treatment was: 8 pts flecainide, 10 propafenone, 12 amiodarone, 15 amiodarone+ flecainide, 3 sotalol and 3 without antiarrhythmic therapy. We evaluated AF recurrence at one week after ECV, 1 month, 3 and 6 months.

Results: One week after successful ECV 16/51 pts (31%) presented AF recurrence (8 pts on amiodarone treatment, 2 pts on amiodarone+ flecainide, 1 pt on sotalol, 1 pt on flecainide, 4 pts on propafenone). In 8 patients we preferred rate control strategy. In the 8 pts in treatment with amiodarone, 150 mg/die of flecainide were added restoring sinus rhythm within a week. In the 2 pts on IC drugs SR was restored within a week increasing the dose of antiarrhythmic. At the 3 month follow-up AF recurrence was showed in 2 more pts 2 (2/43, 4.6%). The six-month follow up was performed in 37 pts and did not show new episodes of AF.

Conclusions: In our study, we can confirm that the relapse rate of AF within a week after ECV is as high as 31% of the cases. A more aggressive antiarrhythmic treatment in the first weeks after ECV can help maintaining SR or in the case of AF recurrence, can restore SR.

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12.2 RECURRENT ARRHYTHMIAS AFTER SUCCESSFUL ELETRICAL CARDIOVERSION OF ATRIAL FIBRILLATION IN PATIENTS WITH HYPERTENSION

*J. Makmur, **M. Mariani, ***E. Arosio, *M. Ivaldi *Casale Monferrato Hospital, Novara, Italy **Ivrea Hospital, Ivrea, Italy ***Vercelli Hospital, Vercelli, Italy

Introduction: Hypertension is a well known common cause of atrial fibrillation (AF). Electrical cardioversion (ECV) is currently the most effective way to convert persistent AF to sinus rhythm (SR). After successful ECV the recurrent arrhythmias may occur for weeks or months. The aim of the study is to evaluate the factors that might influence this phenomenon.

Methods: Ninety-six patients (pts) (67 men, 51–86 years) with persistent AF were included in this study after electrical conversion to SR. All pts underwent an echocardiographic (ECHO) study and electrocardiographic (ECG) evaluation. The following ECHO parameters were determined: ventricular end-systolic (LVES) and end-diastolic (LVED) diameters, septal (SIV) and posterior wall (PW) thickness, ejection fraction (EF), and left atrial diameter (LAD). The presence and type of biphasic P-wave in V1 and inferior leads and duration of P-wave were assessed on ECG.

Results: Twenty-two of 96 pts (22.9%) had recurrence of AF. This occurred in 55%, 35% and 10% of pts with EF<40%, EF of 40–50% and EF>50% respectively. All pts had increased diameter of left atrium. The SIV and PW thickness had higher values in pts with AF recurrence than in those without. There was no statistically significant difference between the two groups regarding electrocardiographic parameters.

Conclusions: Recurrent arrhythmias after successful ECV in hypertensive pts is more highly correlated to diastolic than systolic dysfunction.

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12.3 BACHMANN BUNDLE INVOLVEMENT AND THE MANAGEMENT OF PERSISTENT ATRIAL FIBRILLATION WITH INTRACARDIAC LOW-ENERGY DIRECT CURRENT ELECTRICAL SHOCK

*N. Gjorgov, *D. Kovacevic, *L. Poposka, *I. Trajkov, *V. Boskov *Institute for Heart Diseases, University Clinical Centre, University of Sts Cyril and Methodius, Skopje, Republic of Macedonia

Introduction: The Bachmann bundle is considered the predominant and preferred route for electrical impulse conduction from the right atrium towards the left atrium during sinus rhythm.

Methods: We present a report of a patient with a normal structured heart and no underlying heart disease in persistent atrial fibrillation referred for conversion. On three occasions he was unsuccessfully managed with transthoracic direct current electric cardioversion, and was then referred for an attempt at sinus rhythm restoration with low-energy intracardiac direct current electrical cardioversion. Patient was adequately anticoagulated, and his anti-arrhythmic medication (Propafenone 150 mg tid) was not discontinued. He did not take any other medications. Electrophysiological study was performed for the purpose of restoring normal sinus rhythm. One fixed curve decapolar electrode catheter with 5 mm interelectrode spacing was introduced from the left cubital vein and positioned in the coronary sinus. Another similar fixed curve decapolar catheter was introduced from the right femoral vein and positioned in the right atrium. An additional quadripolar electrode catheter (introduced through the right femoral vein) was positioned in the right ventricular apex for synchronizing the low-energy shock to the R-wave.

Results and Conclusions: Intracardiac electrogram revealed atrial fibrillation in the left atrium and fast atrial flutter in the right atrium. Low energy shocks were delivered between the two decapolar catheters in 1 Joule increments. Patient successfully converted to sinus rhythm with 6 J. After overnight observation the patient's surface electrocardiogram revealed a prolonged and notched P wave, indicative of Bachmann bundle conduction abnormality as a potential cause of the atrial fibrillation. We conclude that intracardiac low-energy direct current electrical shock is a procedure that should be attempted when traditional transthoracic direct current cardioversion is unsuccessful for the management of atrial fibrillation. Our case report also suggests that Bachmann bundle conduction block may be the underlying mechanism of atrial fibrillation when external electrical cardioversion fails.

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12.4 EFFECTIVENESS OF DIFFERENT RIGHT VENTRICULAR PACING SITES AFTER AV NODE ABLATION IN PERMANENT ATRIAL FIBRILLATION

*O. Kalejs, *N. Nesterovics, *M. Blumbergs, *M. Vikmane, *K. Jubele, *P. Sipacevs, *G. Kamzola, *J. Ansabergs, *M. Stabulniece, *J. Jirgensons, *A. Lejnieks *Riga Stradins University, P. Stradins University Hospital, Riga, Latvia

Introduction: The aim of this study was to evaluate the effects of different sites of right ventricular (RV) pacing after AV node ablation in pts with permanent drug refractory atrial fibrillation (PAF).

Methods: From December 2003 to December 2005, 44 pts with highly symptomatic PAF longer than one year and high ventricular rate not controlled by drugs, underwent AV node ablation and VVIR PM implantation. The left ventricular ejection fraction (LVEF) was <50% (mean 43%± 7%) in all pts. Twenty-four pts had a heart failure with a NYHA class III without a clear indication for CRT in any (QRS >100 ms, mean 120 ms ± 20 ms). As optimal pacing site we selected in some patients (group A) the high RV septum and in the other patients (group B) the RV apex. Then we compared the outcome of group A and group B patients during the follow-up.

Results: In the whole group A and group B population, pacing threshold decreased from 1.8 ± 0.6 V intraoperative to 1.1 ± 0.3 V 2–4 hours after implantation, and >1 V 24 h after implantation in 85% of cases. The pacing threshold remained stable during the subsequent follow-up. NYHA improved in twenty of the 24 patients who were initially in class III. The mean LVEF increased to 46 ± 5% after 1 month and to 51 ± 5% after 6 months. QRS duration was 110 ± 20 ms in group A vs 210 ± 30 ms in group B. Group A patients showed a greater and faster increase in LV function, NYHA class, quality of life and walking test (p < 0.05 for all).

Conclusions: High RV septal pacing seems to be superior to RV pacing in patients with atrial fibrillation who undergo ablate and pace therapy.

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Thumbnail image of graphical abstract

Figure 1. BMI vs. ADFT

12.5 PREDICTORS OF TRANSTHORACIC BIPHASIC ATRIAL DEFIBRILLATION THRESHOLDS

*G.G. Bashian, **M.J. Niebauer, *M.K. Chung, *M.S. Lauer, *P.J. Tchou *Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, USA **Section of Cardiology, Internal Medicine, Nebraska Medical Center, Omaha, USA

Introduction: Initial energy requirements for transthoracic DCCV remain undefined. Excessive energy can cause post-shock myocardial dysfunction, brady-arrhythmias, pain, and cutaneous burns. Inadequate energy may result in multiple shocks with associated discomfort, time, and total energy delivered. The aim of our study was to examine the effects of clinical and echocardiographic factors on atrial defibrillation thresholds (ADFT) using biphasic external defibrillators.

Methods: Biphasic-DCCV was performed in 158 patients with persistent AF using a step-up energy protocol (5–200 J) until patients were cardioverted. BMI, age, sex, AF duration, LVEF, LA size, CAD, hypertension, valvular disease, IDCM, and anti-arrhythmic use were evaluated in a multivariate linear regression model using restricted cubic splines.

Results: Four variables demonstrated statistically significant direct correlation to ADFT: BMI (p < 0.001), hypertension (p = 0.019), amiodarone use (p = 0.039), and AF duration (p = 0.041). BMI (Figure 1) showed the greatest effects (F = 15.14 vs. 5.57, 4.33, and 3.29 respectively). There was no interaction between these variables.

Conclusions: These results demonstrate that BMI, hypertension, amiodarone use, and AF duration each independently affect ADFT, with BMI having the strongest correlation. These data may be clinically useful to choose the optimal initial shocking energy when cardioverting AF.

image

Figure 1. BMI vs. ADFT

12.6 ARRHYTHMOGENIC POTENTIAL OF A PERCUTANEOUS IMPLANTED OKKLUDER IN PATIENTS WITH ATRIAL SEPTAL DEFECT OR PERSISTENT FORAMEN OVALE

*H. Neuser, *A. Langbein, *F. Von Hoch, *S. Kerber, *B. Schumacher *Center of Cardiovascular Medicine, Bad Neustadt/Saale, Department of Cardiology, Bad Neustadt/Saale, Germany

Introduction: The percutaneous closure of a secundum atrial septal defect (ASD) or a persistent foramen ovale (PFO) with cryptogenic stroke is well established. Safety and efficacy have been demonstrated in several studies, but there are limited data concerning the risk of arrhythmias caused by the device itself or during the tissue healing process.

Methods: Patients (pts) with PFO and cryptogenic stroke or hemodynamically relevant ASD underwent catheter closure after ascertainment of the initial arrhythmia status. During follow-up after 3, 6 and 12 months, we interrogated all patients with regard to symptomatic rhythm disorders (including paroxysmal disorders) and aimed to document the arrhythmias by ECG, Holter-ECG or event-recording.

Results: We implanted different types of okkluders (occlusion – obstraction?) (35xAmplatzer®; 98x Helex®; 5x Premere®; 6x Cardiastar®) in 144 pts (70 males, mean age 49,7 yrs) and followed up 95 of them. 7 (7.4%) pts suffered from various arrhythmias before the procedure (4 permanent atrial fibrillation (AF), 2 paroxysmal AF, 1 atrial flutter). Two pts with PFO developed AF during the procedure; both episodes terminated spontaneously. In 8 pts (8.4%) we registered new arrhythmias during follow-up: 6 paroxysmal AF (1 ASD, 3 PFO); 2 pts developed typical atrial flutter and 2 pts supra-ventricular bigemini. Six of the 8 episodes occurred in the first 3 months after implantation. In 4/8 pts an Amplatzer® (mean diameter 24.8 mm) had been used, in 2 pts a Helex®-system (diameter 20 resp. 25 mm) and in 2 pts a Cardiastar-Okkluder (30 mm). We found no sustained atrial or ventricular arrhythmias. All pts with AF were treated successfully with anti-arrhythmic drugs (5 ß-blocker, 1 flecainide); 1 pt with atrial flutter requested ablation of the cavotricuspid isthmus. A significant inter-atrial shunt was excluded in all pts.

Conclusions: Atrial-septal defects or patent foramen ovale with cryptogenic stroke are associated with a higher prevalence of paroxysmal atrial fibrillation. Thus, interventional (ablative) therapy should be considered before okkluder (occlusion – obstraction?) implantation. Post-procedural arrhythmias occur more often when bigger systems are used and in the early phase after implantation. These might be caused by mechanical stress.

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12.7 ATRIOVENTRICULAR NODE ABLATION: IS IT STILL AN OPTION?

*I. Nault, *G. O'Hara, *F. Molin, *M. Gilbert, *F. Philippon, *L. Blier, *M. Gilbert *Institut de Cardiologie de Québec, Québec, Canada

Introduction: Therapeutic options for refractory atrial tachyarrhythmia include atrioventricular (AV) node ablation with pacing. The literature reports a deleterious effect of right ventricular (RV) apical pacing. We sought to study long term effects of pacing following AV node ablation on ventricular function.

Methods: We retrospectively revised 161 charts of patients with AV node ablation and follow up: data on ventricular function, co-morbid conditions and length of follow up were collected.

Results: Mean age was 63 ± 11 years. EF was 55% before ablation and 53% (p = 0.048) at follow up (55 ± 38 months).

EF≥50%40–49%30–39%<30%
Baseline73%9%10%8%
Follow-up68%14%11%7%

Left ventricular end diastolic diameter and left atrial diameter did not change significantly. Within the follow up, 5 patients underwent upgrade to a CDI and 2 to a CDI-BiV. During the follow up, 29 patients suffered from an acute exacerbation of heart failure, although in most cases, co-morbid conditions contributed to the episode.

Conclusions: After a follow up of 5 years in patients with conventional pacing following AV node ablation, a small decrease in EF is observed, mostly from normal to mildly depressed EF. In patients with normal EF, AV node ablation with conventional pacing can be a safe option with a possibility of upgrade to biventricular pacing if clinical deterioration occurs.

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12.8 OUTCOME OF HYBRID THERAPY OF CAVO-TRICUSPID ISTHMUS ABLATION AND ANTI-ARRHYTHMIC DRUGS IN ATRIAL FIBRILLATION WITHOUT DOCUMENTED ATRIAL FLUTTER

*P. Van Der Voort, *A. Meijer *Department of Cardiology, Catharina Hospital, Eindhoven, the Netherlands

Introduction: Right atrial ablation does not cure AF. However, patients who demonstrate atrial flutter after initiation of class IC drugs or amiodarone may benefit from ablation of the Cavo-Tricuspid isthmus. For AF patients without documented atrial flutter, the outcome of isthmus ablation in combination with these drugs is not known.

Methods: In 55 patients with paroxysmal (42) or persistent (13) drug refractory, symptomatic AF, a diagnostic EP study and isthmus ablation was performed. Antiarrhythmic drugs used were amiodarone (n = 14), disopyramide (n = 8) and flecainide (n = 29). Before and after ablation, patients kept a symptom diary, recording onset and end of all AF episodes during 4 weeks, from which we calculated the number of AF episodes, episode duration and total AF duration.

Results: AF recurred in all patients except 2, who remained free using amiodarone. Time to recurrence of AF ranged from 9 to 511, median 44 days. After ablation, there was no change in reported Total AF duration (median 2.845 to 2.656 min) or episode duration (median 184 to 165 min). However, the number of AF episodes decreased from 16 ± 17 to 9 ± 10 (p = 0.004). Comparison of patients with early or late recurrence of AF did not show differences in clinical and electrophysiological parameters.

Conclusions: Hybrid therapy of antiarrhythmic drugs and Cavo-Tricuspid ablation do not eliminate AF. However, selected patients may have prolonged AF free periods and a reduction in the number of AF episodes.

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13. ICD: PRIMARY PREVENTION OF SUDDEN DEATH

13.1 PROPORTION OF PATIENTS WITH IDIOPATHIC DILATED CARDIOMYOPATHY AND SCDHEFT CHARACTERISTICS ON DIAGNOSIS AND DURING FOLLOW-UP

†M. Zecchin, *D. Gregori, †A. Di Lenarda, †A. Pivetta, †M. Merlo, †G. Sinagra †Azienda Ospedaliero-Universitaria “Ospedali Riuniti,” University of Trieste, Trieste, Italy *Department of Public Health and Microbiology, University of Turin, Turin, Italy

Introduction: Aim: to evaluate how the proportion of candidates for ICD changes on diagnosis and during regular follow-up on optimal medical treatment, and to identify candidates for early implantation.

Methods: Patients with idiopathic DC enrolled in our Registry from 1988 to April 2006 were evaluated on diagnosis and after 6, 12, 24 and 60 months (mo) to assess the number of candidates for ICD implantation according to SCDHeFT criteria.

Results: 605 patients (age 45 ± 14, LVEF 0.32 ± 0.11, 23% in III-IV NYHA class) were evaluated. During this period, 80% were treated with β-blockers and 86% with ACE-inhibitors. The proportion of patients with SCDHeFT criteria dropped from 47% (on diagnosis) to 20% after 6 months, but remained stable afterwards (20% at 12 mo, 18% at 24 mo and 20% at 60 mo).

On multivariable analysis, LVEF (OR 0.42, 95% CI 0.26–0.66, p < 0.001 for interquartile increase), ystolic blood pressure (OR 0.64, 95% CI 0.43–97, p = 0.034) and the presence of mitral regurgitation > ¼ (OR 1.84, 95% CI 0.97–3.50, p = 0.06) were associated with a higher risk of maintaining SCDHeFT characteristics.

Conclusions: The proportion of patients with DC and SCDHeFT characteristics dropped significantly after 6 months on optimal medical treatment, but remained stable afterwards; pts with lower LVEF, lower systolic blood pressure and mitral regurgitation were more likely to maintain SCDHeFT characteristics despite optimal medical treatment. These data should be considered when choosing the timing of implantation.

Abstract

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13.2 GENDER DIFFERENCES AMONG ISCHEMIC PATIENTS IMPLANTED WITH ICD FOR PRIMARY PREVENTION: DATA FROM CAMI GUIDE STUDY

*M. Landolina, *A. Vicentini, **A. Castro, ***S. Orazi, ****P. Diotallevi, †M. Sassara, ††L. Padeletti, †††A. Pozzolini, ††††F. Accardi, ††††G. Raciti, ‡L.M. Biasucci, ‡F. Bellocci *IRCCS Policlinico San Matteo, Pavia ; **Ospedale Sandro Pertini, Rome ; ***Osp S. Camillo de Lellis, Rieti ; ****A O SS. Antonio e Biagio e Cesare Arrigo, Alessandria ; †Ospedale Belcolle, Viterbo ; ††A.O.Univ. Careggi, Florence ; †††Osp. S.Croce, Fano ; ††††Boston Scientific, Milan ; ‡Policlinico Agostino Gemelli, Rome; Italy

Introduction: Ischemic patients with depressed ventricular function meet indications for ICD according to current guidelines. Gender related differences may illuminate a different epidemiology and assist in risk stratifications.

Methods: From the CAMI GUIDE study population, which enrolled post MI patients with EF≤30, a proportion of male and female patients was analysed for clinical characteristics and compared to other large trials.

Results: Of 302 patients, 35 were female (11.5%), compared to 16%, 23% and 33% from MADIT II, SCD-HeFT and COMPANION trials, respectively. Clinical characteristics of female vs. male groups did not differ significantly for the following variables: HF history (70% vs. 66%), diabetes (36% vs. 29%), stroke (6% vs. 11%), hypertension (57% vs. 50%) and QRS (120 ± 39 vs. 126 ± 33). Women were older (71 ± 7 vs. 67 ± 7 years; p < 0.05), had more advanced NYHA class (50% vs. 41%; p < 0.05), more LBBB (48% vs. 39%; p < 0.05), less atrial fibrillation (2% vs. 15%, p = 0.05) and underwent less CABG (14% vs. 33%; p = 0.02).

Conclusions: Compared to previous large trials, women are under-represented among the patients indicated for ICD for primary prevention in the CAMI GUIDE study. Significant epidemiological differences related to gender may have relevant clinical implications in risk stratification scenarios.

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13.3 DO PATIENTS IMPLANTED WITH ICD FOR PRIMARY PREVENTION MATCH THE CHARACTERISTICS OF THE POPULATION OF CLINICAL TRIALS? INSIGHTS FROM THE CAMI GUIDE POPULATION STUDY

*F. Bellocci, *L. M. Biasucci, *G. Giubilato, **A. Vicentini, ***A. Castro, ****S. Orazi, †P. Diotallevi, ††M. Sassara, †††A. Kheir, ††††G. Zuin, ‡F. Achilli, ‡‡G. Raciti *Policlinico Agostino Gemelli, Rome ; **IRCCS Policlinico San Matteo, Pavia ; ***Ospedale Sandro Pertini, Rome ; ****Osp. S. Camillo de Lellis, Rieti ; †Az. Osp. SS. Antonio e Biagio e Cesare Arrigo, Alessandria ; ††Ospedale Belcolle, Viterbo ; †††Policlinico S. Pietro, Bergamo ; ††††Ospedale Umbeto I, Venice-Mestre ; ‡Osp. A. Manzoni, Lecco ; ‡‡Boston Scientific, Milan; Italy

Introduction: Patients implanted with ICD for primary prevention in current clinical practice may display different clinical characteristics to those found in large population trials and may be exposed to different risks.

Methods: The aim of the analysis is to test whether, in post-MI patients with low ejection fraction (≤30%) selected for ICD implantation in the CAMI GUIDE study, clinical characteristics match those of MADIT II and SCD-HeFT trials.

Results: Three-hundred and two patients were analysed, 36% of whom were implanted with a CRT device. All values (median or percentage) in subsets implanted with ICD and CRT are tabulated below with respect to MADT II and SCD-HeFT data.

 Cami GuideMadit IICami Guide (ICD)SCD HeFTCami Guide (CRT)
Age6864676068
Male8884877788
LVEF2623262526
NYHA>II4130403041
Diabetes2833273129
Hypertension5353545652
AF129111613
Ace inhibitors6468568369
B-Blockers6670706960
Diuretics8572868285
Statins4667393850

Conclusions: Patient characteristics correlate well to the population of major primary prevention trials, with the exception of age, gender and functional class. Although the results of these trials have been incorporated into current guidelines, the tendency to implant patients with worse functional class may indicate the need for an additional risk stratification.

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13.4 DO ISCHEMIC PATIENTS TREATED FOR PRIMARY PREVENTION WITH ICD SHARE THE SAME RISK AS PATIENTS WITH CRT-D? INSIGHTS FROM THE CAMI GUIDE STUDY POPULATION

*P. Diotallevi, *P. De Marchi, **M. Landolina, ***A. Castro, ****F. Evangelista, †A. Achilli, ††M. Piacenti, †††O. Bramanti, ††††R. Massa, ‡C. Indolfi, ‡‡F. Accardi, ‡‡G. Raciti, ‡‡‡F. Bellocci *A. O. S. S. Antonio e Biagio e Cesare Arrigo, Alessandria ; **IRCCS Policlinico San Matteo, Pavia ; ***Ospedale Sandro Pertini, Rome ; ****Osp S. Camillo de Lellis, Rieti ; †Ospedale Belcolle, Viterbo ; ††Istituto di Fisiologica Clinica C.N.R., Pisa ; †††Az Univ. Policlinico G. Martino, Messina ; ††††Osp. S. Giovanni Battista, Turin ; ‡Azienda Ospedaliera Mater Domini, Catanzaro ; ‡‡Boston Scientific, Milan ; ‡‡‡Policlinico Agostino Gemelli, Rome; Italy

Introduction: Ischemic patients with depressed ventricular function implanted with ICD for primary prevention may also meet the indication for CRT. These two groups of patients may show different risk profiles.

Methods: Proportions and clinical characteristics of these two groups from the CAMI GUIDE study are compared and their risk of ventricular arrhythmias, cardiac hospitalizations and total mortality are analyzed over follow-up.

Results: Of 302 patients 36% were implanted with a CRT device. Excluding parameters used to select patients for CRT (QRS, NYHA class and LBBB), clinical characteristics of CRT and ICD patients were no statistically different for any parameters considered (previous CABG: 29% vs. 31%; diabetes: 29% vs. 29%; stroke: 10% vs. 9%; hypertension: 59% vs. 49%; AF: 12% vs. 15%; age: 69 ± 9 vs. 67 ± 10; EF: 26 ± 4 vs. 26 ± 4). Over a 12 month follow-up, mortality (13% vs. 9%) and ventricular arrhythmias (19% vs. 13%) did not differ significantly while no case of cardiac hospitalization was observed in CRT group (0% vs. 12%; p < 0.01).

Conclusions: Ischemic patients indicated for primary prevention implanted with ICD share similar clinical characteristics and risks as those meeting indications for CRT, except for a higher rate of cardiac hospitalization post implantation.

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13.5 ROLE OF ICD IN PRIMARY PREVENTION PATIENTS: PREDICTIVE PARAMETERS OF APPROPRIATE ICD PROCEDURES (AURA STUDY)

*C. D'Agostino, **G. Campanale, ***A. Iuliano, ****P. Gallo, †G. De Fabrizio, *M. Palella, **E.G. Campanale, ***P. Guarini, ††C. Ciardiello, ***G. Stabile *P.O. Di Venere, Carbonara di Bari, Bari ; **Ospedale Regionale F. Miulli, Acquaviva delle Fonti, Bari ; ***Laboratorio di Elettrofisiologia Clinica Mediterranea, Naples ; ****Casa di Cura Villa Dei Fiori, Acerra, Naples ; †Ospedale G. Moscati, Avellino ; ††Boston-Guidant; Italy

Introduction: Purpose of the study is to assess the rate of appropriate ICD procedures among primary prevention patients in specific subgroups selected by clinical parameters.

Methods: Seventy nine patients (male 86%, mean age 66 ± 10 years, with NYHA functional class II (22%) and III (72%), 62% ischemic (CAD), 38% idiopathic dilated cardiomyopathy (IDIO)) received an ICD due to LVEF<35%. ICD were programmed with Ventricular Tachycardia (VT) and Ventricular Fibrillation (VF) (160–200 and >200 bpm) zones, with shock therapy in VT and FV and anti-tachy pacing in VT. We tested gender, age, LVEF, CAD, NYHA class and presence of atrial fibrillation at implant as possible predictive parameters of appropriate ICD procedures.

Results: At 18 month median follow-up an appropriate ICD procedure was reported in 40.2% of patients (26.4% in VT and 19.4% in VF zone). No statistically significant difference was observed for all parameters. At VT zone a higher rate of appropriate procedure was found for IDIO group compared with CAD (40.7% vs 17.8% p = 0.013).

Conclusions: Although IDIO patients received nearly as many ICD interventions as CAD patients, many more therapies were applied at VT.

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13.6 ICD PROCEDURES IN PRIMARY PREVENTION OF SUDDEN CARDIAC DEATH: TIME AND FREQUENCY ANALYSIS IN AURA STUDY

!*G. De Fabrizio, **A. Iuliano, ***P. Gallo, ****G. Campanale, †C. D'Agostino, **A. De Simone, ***P. Guarini, ****E.G. Campanale, †C. Ciardiello, **G. Stabile*Ospedale G. Moscati, Avellino; **Laboratorio di Elettrofisiologia Clinica Mediterranea, Naples; ***Casa di Cura Villa Dei Fiori, Naples, ****Ospedale Regionale F. Miulli, Acquaviva delle Fonti, Bari; †P.O. Di Venere, Carbonara di Bari, Bari; ††Boston-Guidant; Italy

Introduction: The objective of this study is to assess the frequency and time distribution of ICD delivered therapies in primary prevention patients.

Methods: Seventy-nine patients (male 86%, mean age 66 ± 10 years, with NYHA functional class II (22%) and III (72%), ischemic 62%, primitive dilated cardiomyopathy 38%) received an ICD due to LVEF <35%. ICD was programmed with Ventricular Tachycardia (VT) and Ventricular Fibrillation (VF) (160–200 and >200 bpm) zones. Shock therapy was programmed in VF and VT zones whereas anti-tachy pacing in VT zone only.

Results: At 18 month median-follow-up a correct ICD xxx was reported in 40.2% of patients (26.4% in VT and 19.4% in VF zone), whereas 26% of patients received multiple therapies. Seven patients died at follow-up stage. The percentage of patients who received the first appropriate intervention at 6, 12 and 18 month follow-up was 15.3, 29.2 and 33.3 respectively.

Conclusions: Seventy-five per cent of patients with appropriate ICD procedure received therapy within the first 12 months after implant. These findings suggest that special care is needed in device management in the first period after ICD implantation.

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13.7 INCIDENCE, CAUSES, TIMING, AND CLINICAL IMPLICATIONS OF INAPPROPRIATE THERAPY IN PATIENTS RECEIVING ICDS USING MADIT I AND MADIT II IMPLANTATION CRITERIA

*K. Sonne, *J.C. Geller, *S. Reek, *J. Mittag, *H. Klein *Zentralklinik Bad Berka, Division of Cardiology, University Hospital Magdeburg, Bad Berka, Germany

Introduction: There is limited information about the incidence, causes and timing of inappropriate therapy after ICD implantation for primary prevention of sudden cardiac death regarding different implantation criteria during long-term follow up.

Methods: Age-matched patients who received a prophylactic ICD (111 patients) at our institution between May 1996 and December 2002 using MADIT I (57 patients, group I) and II (54 patients, group II) criteria were compared.

Results: During a mean (±SD) follow-up time of 41 ± 25 months, 30 patients (27%) experienced appropriate and 18 patients (16.2%) received inappropriate ICD treatments. The mean time (range) to the first inappropriate treatment was 20 ± 16.7 (0.5–66.5) months. The main cause of inappropriate therapy was atrial fibrillation in 10 patients, followed by lead failure in four patients, sinus tachycardia in one patient and atrial tachycardia in three patients. There were no significant differences between Group I and Group II.

Conclusions: Inappropriate treatment remains a significant problem in ICD patients resulting in reduction in quality of life. Careful programming of available enhanced detection criteria could result in a lower number of inappropriate shocks.

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13.8 PROGNOSTIC RISK OF SLOW VENTRICULAR TACHYCARDIA IN PATIENTS AFTER AICD IMPLANTATION

*T. Higuchi, *K. Kaitani, *J. Sakamoto, *M. Miyake, *M. Motooka, *T. Izumi, *H. Gen, *C. Izumi, *Y. Nakagawa *Department of Cardiovascular Medicine, Tenri-Yorozu Hospital, Tenri, Japan

Introduction: The incidence of haemodynamically tolerated slow ventricular tachycardia (VT) in ICD patients remains largely unknown. The present study aimed at determining the impact on clinical outcome of slow VT in patients after ICD implantation.

Methods: We analyzed retrospective data of 24 patients who underwent ICD implantation between January 2001 and December 2006. All cases were implanted for secondary prevention. We calculated the incidence of sustained or non-sustained slow VT(s), defined as a mean VT Cycle Length≥450 ms through the ICD telemetry data. We also evaluated the outcome of patients with/without slow VT(s).

Results: During the follow-up (26 ± 16 months), 7 patients experienced documented slow VT (sVT group) and 17 patients did not (fVT group). The mean Cycle Length of slow VT was 496 ms. Sudden cardiac death occurred in 3 of the 7 patients in sVT group compared with only one of the 17 patients in fVT group.(43% vs. 6%; p < 0.01).

Conclusions: In patients with ICD, the occurrence of slow VT seems to be associated with increased subsequent mortality.

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14. CRT: IMPLANTATION ASPECTS AND IMPORTANCE OF INTERATRIAL AND INTERVENTRICULAR DELAY

14.1 A NEW LEFT VENTRICLE PACING LEAD WITH ACTIVE FIXATION: THE NIGUARDA HOSPITAL EXPERIENCE

*G.B. Magenta, *G. Cattafi, *M. Paolucci, *M. Schirru, *M.R. Vecchi, **V. Burrone, *M. Lunati *De Gasperis Department, Niguarda Ca’ Granda Hospital, Milan, Italy **Medtronic Italia spa

Introduction: LV dislodgements are the primary cause of lead related complications in CRT implants. The Medtronic Attain StarFix 4195 is a new lead for LV stimulation with deployable lobes on the distal end of the lead to provide stable placement inside a branch of coronary sinus.

Methods: From November 2006 to March 2007, 26 patients (pts) were implanted with a 4195 lead as a first or a second choice of a selection based upon the venous anatomy. Data on the leads’ electrical performance was collected at implant.

Results: We successfully implanted a 4195 lead in 25 (mean age 62.5 ± 8.48, 70% males) out of 38 pts who underwent CRT implant and in one pt who had a prior device. The lead position caused diaphragmatic stimulation in only one pt. However, the implant was successfully performed using bipolar LV lead (Attain Bipolar OTW 4194). LV pacing threshold (at 0.5 ms), sensing (mV) and impedance (Ω) were respectively 0.7 ± 0.5 V, 16.2 ± 6.7 mV, 758 ± 242 Ω.

Conclusions: The Attain StarFix lead improves stability across a range of vein sizes, with trackability and electrical performance comparable to the Attain OTW family.

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14.2 LONG-TERM PERFORMANCE OF CORONARY SINUS LEADS USED FOR CARDIAC RESYNCHRONIZATION THERAPY: POLARITY AND AETIOLOGY ANALYSIS

!*E. Bertaglia, **V. La Rocca, ***F. Solimene, **A. De Simone, *F. Zerbi, *P. Pascotto, ****M. Accogli, **A. Iuliano, †G. Marras, **G. Stabile*Ospedale Civile, Mirano**Casa di Cura San Michele, Maddaloni (CE)***Clinica Montevergine, Mercogliano (AV)***Azienda Ospedaliera Pia Fondazione Cardinale G. Panico Tricase (LE)†Boston-Guidant, Italy

Introduction: To date little is known regarding long-term coronary sinus (CS) leads performance. We evaluated the correlation between lead polarity and aetiology of patients with CS leads performance at long-term follow-up.

Methods and Results: Between February 1999 and July 2004, 188 patients (143 male; mean age: 68±9 years, NYHA class III: 68%; left ventricle ejection fraction (LVEF): 26.6±7.2; 48% idiopathic dilated cardiomyopathy, 47% ischemic, 5% other) underwent CRT implantation. The leads used were unipolar (85 Guidant Easytrak 1, 15 and 14 Medtronic Attain LV and OTW) and bipolar (64 and 10 Guidant Easytrak 2 and 3). We compared the pacing energy (μJ) expressed by median and interquartile range at implant (unipolar: 0.96–2.03, bipolar 0.62–1.80, idiopathic: 0.64–1.70 and ischemic: 0.76–2.0) and at median 37 month follow-up (unipolar: 3.63–8.68, bipolar 1.05–3.67, idiopathic: 1.50–7.63 and ischemic: 1.21–5.16). Stimulation energy increased more in idiopathic patients but only the unipolar leads showed a significant statistical increase in energy (non parametric test p = 0.012).

Conclusions: At long-term follow-up, bipolar leads showed a better electrical performance in comparison with unipolar leads and regardless of aetiology.

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14.3 ECG OPTIMIZATION OF CRT THROUGH SINGLE-SITE LV PACING IN PATIENTS WITH HF, LBBB AND SR

*L. Gianfranchi, *K. Bettiol, *F. Pacchioni, *P. Alboni *Department of Cardiology, Hospital of Cento, Cento, Italy

Introduction: In CRT patients with SR, HF and LBBB, we hypothesize that electrical fusion between LV pacing and spontaneous RV activation, evaluated through ECG, leads to mechanical resynchronization.

Methods: We enrolled 12 patients (7 males, 63±12 yrs) treated with CRT. ECG was recorded at each programmable AV delay, starting from the one that leaves native LBBB unaltered. On shortening the AV interval, we obtained a series of ECG showing, mainly in V1, progressive transition in morphology from LBBB to a completely left pre-excited RBBB, passing through intermediate QRS of “fusion”. The “fusion band” was defined as the range of AV intervals within which ECG shows intermediate morphology between the LBBB pattern and the fully paced RBBB pattern. The upper limit of the band was set at 40 ms shorter than the intrinsic interval (atrium-VD). The lower limit was set at the AV interval that yielded an RBBB-like morphology. Two intermediate AV intervals were also evaluated. We evaluated: diastolic filling time, Tei index, indexes of asynchrony by TDI (Ts-12-ejection, Ts-SD-ejection), and inter-ventricular delay .

Results: Data related to the fusion band show the average of the 2 intermediate AV intervals.

Results (12 pts)LBBBFusion bandp
Tei index0.81 ± 0.190.53 ± 0.110.006
Ts-12-ejection (ms)166 ± 36 88 ± 220.037
Ts-SD-ejection (ms) 66 ± 17 29 ± 80.046
Interventricular delay (ms) 42 ± 11 13 ± 80.017
Filling time (ms)413 ± 55471 ± 630.062

Conclusions: Tailoring myocardial resynchronization with LV pacing alone from ECG criteria seems feasible and effective. LV pacing could be proposed as a valid option in patients with sinus rhythm.

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14.4 COMPARISON OF P WAVE DURATIONS AS ASSESSED BY THE BIPOLAR AND UNIPOLAR ATRIAL INTRACARDIAC ELECTROGRAMS: APPLICABILITY TO THE QUICKOPT PV DELAY TESTS

*X. Min, *P. Demers, *D. Muller, *J. Snell, *P.A. Levine, *E. Ostrow *CRMD St. Jude Medical, Sylmar, California, USA

Introduction: Studies have shown that inter-atrial conduction time (IACT) can be used to estimate optimal PV delays. SJM QuickOpt utilizes the atrial EGM (AEGM) and measures P-wave duration (PW) to estimate the IACT. This study compares PW between bipolar (Bi) and unipolar (Uni) AEGM in patients (pts) with a pacemaker and a CRT-D.

Methods: Bi and Uni AEGMs were obtained from 42 pacemakers (PP) and 18 CRT-D pts.

Results: In the PP, PW of Bi and Uni AEGMs were close (114 ± 19 ms vs. 110 ± 20 ms). Intra-patient difference was 3.9 ± 8.7 ms and 95% confidence intervals for the difference was (1.2, 6.6) which is within 10 ms criterion. With CRT-D, PW were 79 ± 18.4 ms and 81 ± 14 ms for Bi and Uni sensing. The intra-patient difference was -1.19 ± 14.9 ms and 95% confidence intervals for the difference was (-9.1, 6.8) which is within 10 ms criterion. In 18 PP pts, the difference between ECG and bipolar PW was 4.8 ± 17.8 ms.

Conclusions: PW were similar between unipolar, bipolar atrial IEGMs, and surface ECG indicating that bipolar and unipolar AEGMs can be used as a surrogate for the IACT.

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14.5 ENDOCARDIAL ELECTRIC PARAMETERS IN NORMAL HEARTS AND DILATED CARDIOPATHY

†D. Vaccari, *R. Mantovan, *V. Calzolai, †G. Masaro, †G. Valente, **P. Silvestri, **A. Mantesso, **L. Michelotto, †M. Raccanello, †G.F. Neri †Division of Cardiology, Montebelluna, Treviso, Italy *Cardiovascular Department, Treviso, Italy **St Jude Medical, Italy

Introduction: The aim of our study is to compare the electrical conduction differences between a group of heart failure patients that were candidates for CRT and a group of patients with standard indication for ventricular pacing in normal hearts.

Methods: Group one was composed of 76 patients (23 female, 53 male, mean age 69 ± 9 years) undergoing CRT therapy for advanced heart failure (NYHA class III or IV, ejection fraction (LVEF) ≤35%, QRS interval >120 msec). The control group was composed of 19 patients with normal LVEF and LV dimension and with standard indication for ventricular pacing due to AV conduction defects, but implanted with biventricular devices following the criteria of Biopace (SJM) Study randomization. All patients were implanted with left endocardial lead positioned in the anterolateral, lateral or posterolateral segment. We measured the interval between the spontaneous electrical signal obtained by Right and Left ventricular lead (Rsensed-Lsensed), the interval between spike and opposite ventricular signal (Rpaced-Lsensed and Lpaced-Rsensed), and the correspondent 12 leads QRS width. Echocardiographic resynchronization data was also collected.

Results:

 GR 1 – CMP – 76 ptsGR 2 – NORM – 19 ptsP
  1. AF = atrial fibrillation, LVEF = left ventricular ejection fraction, LVEDVi = left ventricular end diastolic volume index, LVEDD = left ventricular end diastolica diameter, IEGM = intraventricular electrocardiogram, Rpac/Rsen = pacing or sensing from right ventricular catheter, Lpac/Lsen = pacing or sensing from left epicardial catheter.

AGE (y) 69 ± 9 74 ± 90.011
SEX (female%)  30.3  32.00.867
NYHA class  3.0 ± 0.5  1.3 ± 0.60.0001
ISCHEMIC CMP (%) 40 10.50.0001
AF (%)    20  26.30.756
LVEF (%) 27.2 ± 5.6 63 ± 60.0001
LVEDVi (ml/mq)103.9 ± 30.1 45.6 ± 9.90.0001
LVEDD (mm) 68.1 ± 7 50.8 ± 5.30.0001
PQ (msec)181.3 ± 33245.7 ± 500.0001
QRS (msec) 161 ± 26 118 ± 250.0001
IEGM Rsen-Lsen (msec) 87 ± 44 32.4 ± 230.0001
QRS left paced (msec) 191 ± 40 191 ± 281.000
IEGM Lpac-Rsen (msec)123.8 ± 33.9101.4 ± 210.006
QRS right paced (msec) 203 ± 35182.7 ± 210.019
IEGM Rpac-Lsen (msec)130.2 ± 38.0105.3 ± 270.008
QRS biventricular (msec) 141 ± 24 133 ± 190.181
Q-Po (msec) 94.0 ± 43.0 75 ± 200.033
Q-Ao (msec) 131 ± 41 77 ± 210.007
Q-Ao – Q-Po (msec) 37.5 ± 38 −2.3 ± 5.60.002
Q-PL (msec)179.3 ± 53.7 79 ± 270.0001
Q-Siv (msec) 121 ± 59.5 70 ± 200.001
Q-PL – Q-Siv (msec) 58.4 ± 51.8  −9 ± 100.0001

Conclusions: Symptomatic dilated cardiopathy with severe impaired left ventricular systolic function, as well as interventricular desynchronization with prolonged QRS duration, significantly prolong spontaneous intraventricular conduction time (measured by endocardial leads) and paced conduction time, not always revealed by surface QRS. There is a critical minimum value of resynchronized QRS duration of about 130 msec.

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14.6 ELECTRICAL PARAMETERS AS PREDICTIVE INDEXES OF CARDIAC RESYNCHRONIZATION THERAPY RESPONDERS IN CONGESTIVE HEART FAILURE PATIENTS: AN ANALYSIS OF SENSIBILITY AND SPECIFICITY

*L. Santangelo, **C. La Rosa, ***C.D. Dicandia, *E. Ammendola, **S. Vitanza, ***E. Pellegrino, *I. De Crescenzo, ****L. Prato, ****C. Ciardiello *Seconda Università di Napoli, Naples ; **Casa di Cura Villa Verde, Taranto , ***Casa di Cura Città di Lecce (GVM), Lecce ; ****Boston-Guidant; Italy

Introduction: The objective of this study was to analyze different electrical indexes that are potentially predictive of responders in Heart Failure (HF) patients implanted with CRT.

Methods and Results. Seventy-nine patients (gender: 68% male; age: 67 ± 10 years; NYHA class III: 84%; LVEF 24.6 ± 5.9% dilated cardiomyopathy aetiology: idiopathic (IDIO) 50%, ischemic (CAD) 47%, other 3%; QRS duration: 161±29 ms) were implanted with CRT defibrillator with distinct sensing channels (Guidant Contak Renewal IV®). During a 12 month follow-up we defined as responders patients alive without HF hospitalizations who improved the NYHA class of at least one unit (A) or who improved the LVEF of at least 30% (B). Delay (ms) between right and left ventricle signal (VVD) and QRS duration: (spontaneous: QRSs and paced: QRSp) were used to calculate the following parameters: VVD, VVD/QRSs, VVD/QRSp, QRS shortening (QRSs-QRSp). VVD/QRSs>50% was the most sensible index to identify responders (both A and B), for the whole population, CAD and IDIO. VVD>90 ms was the most specific.

Conclusions: VVD and QRS assessments can be of use during procedure to better identify CRT responders.

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14.7 LACK OF PREDICTORS OF OPTIMAL RV-LV DELAY AS ESTABLISHED BY THREE DIMENSIONAL ECHOCARDIOGRAPHY AND AORTIC VELOCITY TIME INTEGRALS

*A. Fischer, *R. Hansalia, *W. Lane Duvall *Divisions of Electrophysiology and Echocardiography, Cardiovascular Institute, Mount Sinai Medical Center, New York, USA

Introduction: The purpose of this study was to evaluate whether there are predictors of optimal RV-LV delay in patients with cardiac resynchronization (CRT) devices. Despite the ability to successfully implant CRT devices, 20–30% of patients will have an inadequate response after implantation. To improve the response rate, optimization of RV-LV delay has been proposed. The precise means to optimize RV-LV delay remains undefined with little data to predict the appropriate sequence of activation of the RV and LV.

Methods: Using three-dimensional echocardiography and aortic velocity time integrals, we evaluated 19 patients to assess the optimal RV-LV delay as determined by dyssynchrony indices and global LV performance. Patients were evaluated after device implantation using multiple RV-LV delays to identify the presence of dyssynchrony and quantitate global LV function.

Results: Of the patients evaluated, seven (37%) had an ischemic cardiomyopathy and twelve (63%) had a non-ischemic cardiomyopathy. The pre-implant QRS was 166 ± 32 ms and post-implant QRS was 137 ± 26 ms. LBBB was present in 53%, paced rhythm in 26%, IVCD in 11% (RBBB was excluded). LV-RV 40 ms produced the best LV performance in 42% of patients, followed by simultaneous LV and RV stimulation in 26% of patients. Less frequently, LV-RV 30(16%), LV-RV 20(11%) and RV-LV 20(5%) led to optimal resynchronization of the RV and LV. None of the clinical variables tested predicted optimal RV-LV delay as determined by echocardiography. A Pearson correlation coefficient for pre-QRS duration and optimal RV-LV delay revealed r2= 0.17. Univariate analysis and a multiple regression model revealed that pre-implant QRS duration, post-implant QRS duration, ΔQRS, QRS morphology and etiology of cardiomyopathy did not predict optimal RV-LV delay (p = 0.8).

Conclusions: We found no features predictive of optimal RV-LV delay in patients with CRT devices. The lack of predictors suggests that echocardiographic evaluation is necessary to obtain optimal resynchronization. Further evaluation of the clinical benefits of RV-LV optimization is warranted in larger clinical trials.

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14.8 INTERVENTRICULAR DELAY IN CRT DEVICES AT IMPLANT AND THEIR RELATION WITH ANATOMICAL LEFT VENTRICULAR LEAD POSITION

*C. La Rosa, **C. Cavallaro, ***C.D. Dicandia, *S. Vitanza, **S. De Vivo, ***E. Pellegrino, ****C. Ciardiello, ****G. Russo, **A. D'Onofrio *Casa di Cura Villa Verde, Taranto ; **A.O. Monadi, Naples ; ***Casa di Cura Città di Lecce (GVM), Lecce ; ****Boston-Guidant; Italy

Introduction: The purpose of this study was to assess the correlation between LV lead position and inter-ventricular delay measured during implantation in heart failure patients implanted with CRT.

Methods and Results: We enrolled 98 patients (gender: 71% male; mean age: 65±11 years; NYHA class III: 83%; mean LVEF 25 ± 5%; aetiology: idiopathic 52%, ischemic 46%, other 2%; mean QRS duration: 158 ± 28 ms) with CRT distinct sensing channels defibrillator devices (Guidant Contak Renewal IV®). During implant the electrical delay (ms) between right and left ventricular leads (VVD) was measured. 61 patients had left ventricular lead implanted in lateral position (L), 20 in posterior or posterior-lateral (P) and 17 in anterior or anterior-lateral (A). Comparing both VVD and VVD/QRS values among different LV lead locations, the anterior position resulted in significantly inferior values for both variables with respect to all other sites. (VVD; L:91 ± 38 ms; P:87 ± 38 ms; A:35 ± 22 ms: p < 0.001) (VVD/QRS; L: 0.56 ± 0.22; P: 0.56 ± 0.24; A: 0.25 ± 0.16: p < 0.001).

Conclusions: Sensed inter-ventricular delay values are associated with left ventricular lead site. Due to known association between lead site and CRT response, effective resynchronization should take into account these measurements and their evolution at follow-up stage.

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Tuesday, October 9, 2007

15. ATRIAL FIBRILLATION: VALUE OF DIFFERENT MAPPING SYSTEMS AND ABLATION TECHNIQUES

15.1 MAPPING SYSTEMS FOR ATRIAL FIBRILLATION ABLATION: A PROSPECTIVE RANDOMIZED STUDY

†R. Mantovan, †M. Crosato, †V. Calzolari, *L. Sacchetti, **L. Montagna, ***A Favaro, †D. Favarato, †V. Rizzato, †Z. Olivari †Cardiovascular Department of Treviso, Treviso, Italy *St Jude Medical **Biosense Webster ***Boston Scientific

Introduction: Three-dimensional mapping systems are useful tools for atrial fibrillation (AF) ablation. More timely fluoroscopy and easier catheter navigation are the main benefits of these devices. The aim of this study is to compare in a prospective, random manner, procedural findings of AF ablation performed either with Carto (Biosense) or NavX (St Jude) mapping systems.

Methods: Sixty consecutive patients (pts) (mean age 55 ± 8 years, female 21; 35%) affected by drug refractory paroxysmal (38), persistent (18) and permanent (four) AF underwent a pulmonary veins (PV) ablation. AF history lasted for 6.3 ± 4 years; arterial hypertension was present in 20 pts (33.3%), tachy-cardiomyopathy was present in two pts (3.3%), previous dysthyroidism due to amiodarone usage had occurred in 16 pts (27%), and six pts (10%) had experienced ischemic cerebral accidents. All pts underwent a PV disconnection with an integrated approach performed by the same operator. Wide encircling lesions were performed around all PVs ostia using irrigated tip catheter. Electrical disconnection was confirmed by circumferential catheter. Thirty pts (mean age 52 ± 10 years, female nine) were randomized to Carto (C group) and 30 pts (mean age 57 ± 7 years, female 12) to Navx (N group). Open irrigation catheters (Thermo Cool, Biosense) were employed in C group, while pts in N group were further randomized to open irrigation catheters (Coolpath, St jude-IBI) and internal irrigation catheters (Chilli II, Boston). The following procedural and fluoroscopy times were evaluated: I – mapping time (time to create the anatomical reconstruction), II – radiofrequency (RF) time (time to achieve all PVs disconnection), III – total procedural time. Other linear lesions and/or lesions performed at fragmented potentials were excluded from this analysis. Finally, the time for electrical isolation of PVs with each catheter was evaluated.

Results: Clinical basal characteristics were comparable in both groups. A median of four PVs were disconnected in all pts. Procedural and fluoroscopy mapping times were 34 ± 8 and 9.6 ± 3 min (C group), 38 ± 8 and 9.8 ± 4 min (N group) respectively (ns). Procedural and fluoroscopy RF time were 110 ± 6 and 25 ± 4 min (C group), 105 ± 10 and 24 ± 10 min (N group), respectively (ns). Total procedural and fluoroscopy time were 185 ± 13 and 43 ± 9 min (C group), 181 ± 16 and 41 ± 13 min (N group), respectively (ns). Mean time for electrical isolation of PVs was 37 ± 9 min with Thermo Cool open irrigation catheter, 38 ± 10 min with Coolpath open irrigation catheter and 39 ± 11 min with Chilli II internal irrigation catheter (ns). One patient developed cardiac tamponade (N group, Coolpath catheter).

Conclusions: Three dimensional Carto and Navx mapping systems are equally effective in PVs isolation for AF ablation. Moreover, both internal and open irrigation catheters seem equally efficacious and safe.

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15.2 INTEGRATION OF THREE-DIMENSIONAL LEFT ATRIAL MAGNETIC RESONANCE IMAGE INTO REAL-TIME ELECTROANATOMIC MAPPING SYSTEM: VALIDATION OF A NEW REGISTRATION METHOD TO GUIDE CATHETER ABLATION OF ATRIAL FIBRILLATION

*G. Brancolino, *F. Zoppo, *F. Zerbo, *P. Pascotto *U.O. di Cardiologia, Ospedale Civile, Mirano-Venice, Italy

Introduction: Image integration techniques have recently been introduced to catheter ablation of atrial fibrillation (AF). The aim of the study is to assess the accuracy of a new simplified technique for the superimposition of 3D magnetic resonance left atrial image on real time left atrial electroanatomic map obtained with 3D mapping system (registration process).

Methods: Magnetic resonance data of left atrium from 40 patients with drug-refractory AF was imported into the new CartoMerge™ electroanatomic mapping system. Registration was obtained from a combination of both “visual alignment” of one endocardial point and “surface registration” of a limited number of points sampled from the posterior wall of the left atrium.

Results: The average registration surface-to-point distance and the average ablation surface-to-point distance resulted in a mean of 1.33 ± 0.96 mm and 1.47 ± 1.15 mm respectively. Upon completion of the circumferential anatomical ablation around the pulmonary veins (PVs), electrical isolation was confirmed by a multipolar circular mapping catheter in 129/146 PVs (89%).

Conclusions: Our simplified registration strategy allows us to isolate almost 90% of PVs by means of an anatomic-based catheter ablation approach.

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15.3 INTEGRATION OF 3D CT IMAGES AND ELECTROANATOMIC MAPPING SYSTEM TO GUIDE ATRIAL FIBRILLATION ABLATION: ACCURACY OF PV OSTIA ALIGNMENT IS DEPENDENT ON THE REGISTRATION STRATEGY

*R. Marazzi, *R. De Ponti, *G. Bartesaghi, *S. Rogiani, *L. Panchetti, *P. Antognazza, *J.A. Salerno-Uriarte *University of Insubria, Department of Cardiovascular Sciences – Circolo Hospital & Macchi Foundation, Varese, Italy

Introduction: The precise identification of pulmonary veins (PV) ostium is possible through integration of CT scan, whereas electroanatomic mapping (EAM) images allow real-time navigation of the ablation catheter. The aim of this study was to compare two different registration strategies in pts undergoing atrial fibrillation (AF) ablation.

Methods: We considered 26 consecutive pts (23 males; age 58 ± 7 years) with drug-resistant AF submitted to ostial PV electrical isolation (EI). Three-D left atrium (LA) image of a 64-slice CT scan was imported into the EAM system (Cartomerge™, Biosense Webster). Image registration was first achieved superimposing the CT image on the EAM of the LA and PV by using a single LA landmark. Then, surface registration to gain the smallest average distance of the two datasets was performed in all the pts by two ways: A – considering both the LA and PV EAM points; B – considering the LA EAM points alone (“active only”). The accuracy of superimposition was defined at each PV ostium in 3 axes (antero-posterior, super-inferior and along the PV trunk axis): the match was excellent when the maximum distance (MD) was ≤2 mm, acceptable when 2 < MD < 5 mm, unacceptable when MD was ≥ 5 mm.

Results: In 26 pts, 102 PVs were evaluated. An excellent match was observed in a significantly greater number of PV (79/102 vs. 42/102 PV; p < 0.05) when the “A” surface registration way was used for alignment vs. the “active only” registration way. The match was unacceptable in 15/102 (15%) PV, mainly in left ones (10/15 PVs), after “A” surface registration way, in 29/102 (29%) PV after “active only” registration way, without prevalence in right or left PV. The mismatch was independent from the type of rhythm during CT scan and EAM, the number of LA/PV EAM points and the LA volume. The “A” surface registration way then adopted for ablation, provided in 21/26 (81%) pts an excellent and/or acceptable match in at least 3 PV ostia and an average distance, calculated by the system, of 2 ± 0.3 mm between the whole EAM and CT surfaces. EI was successful in all the targeted PV without complications.

Conclusions: In our study the registration strategy is crucial for the image integration process. Utilizing both LA and PV EAM points during surface registration, an excellent match was achieved for most PV (77%), allowing a real-time navigation during ablation with minimum fluoroscopy use in the majority of pts (81%). The mismatch, mainly in left PV after this registration strategy, could be related to respiration during CT scan acquisition, with larger excursions on left “free” LA side.

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15.4 SEGMENTAL OSTIAL CATHETER ABLATION (SOCA) OF ATRIAL FIBRILLATION USING VIRTUAL GEOMETRY RECONSTRUCTION WITH NAVX SYSTEM: THE TERNI (TERNI EVALUATION OF PULMONARY VEINS ISOLATION WITH ENSITE SYSTEM) REGISTRY

*S. Nardi, *C. Esposito, *M.M. Pirrami, *C. Marini, *G. Ranalli, *V. Borghetti, *A. Pardini, *G. Ambrosio, *G. Rasetti *Arrhythmia Electrophysiologic Center, Cardiac Pacing Unit, Thoracic Surgery, Cardiovascular Department, Division of Cardiology, AO S. Maria, Terni, Italy

Introduction: EnSite NavX™ is a navigation system that allows for the possibility to create a three-dimensional geometry of cardiac chambers. We hypothesized that this tool may help to guide segmental ostial catheter ablations (SOCA) of atrial fibrillation (AF).

Methods and Results: From July 2004 to September 2006, 145 consecutive patients (64 ± 15) symptomatic of paroxysmal (PaAF 91) or persistent (PeAF 54) AF, despite two or more different anti-arrhythmic drugs (AADs) used alone or in association, underwent SOCA. The ablation procedures were guided both anatomically, by NavX™, and electrophysiogically, with SOCA. After a complete PV isolation (PVI), adjunctive radiofrequency pulses were applied at specific points where electrical disconnection was observed, in order to consolidate efficacy over the time. A complete PVI was reached in 134/149 patients; after a mean FU of 12 months, the overall freedom from AF was 66% (PaAF 72% and PeAF 58%), without AADs and 79% (PaAF 84% and PeAF 70%) with previous ineffective AADs.

Conclusions: In patients undergoing SOCA, a three-dimensional view enabled by NavX™ system is not only reliable but may also bring about new interesting insights for the cure of AF.

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15.5 RADIOFREQUENCY CATHETER ABLATION FOR DRUG-REFRACTORY ATRIAL FIBRILLATION: SEGMENTAL PULMONARY VEIN ISOLATION VERSUS ANTRAL PULMONARY VEIN ISOLATION THROUGH ELECTROANATOMIC CARTOMERGE OR NAVX VERISMO APPROACH

*M.T. Lucciola, *M. Casella, *A. Dello Russo, *G. Pelargonio, *R. Biddau, *M.L. Narducci, *A. Sparagna, *C. Bisceglia, *P. Zecchi, *F. Bellocci, *A. Martino, *F. Perna, *P. Santarelli, *M. Vaccarella, *A. Ricco, *P. Rinaldi, *L. Bonomo *Cardiovascular Medicine Department, Catholic University of the Sacred Heart, Rome, Italy

Introduction: Different strategies are performed in catheter ablation of paroxysmal atrial fibrillation (PAF). Aim of our study was to compare the efficacy of segmental pulmonary vein (PV) ostial ablation and combined approach PV isolation (PVI) plus electroanatomic mapping (CartoMerge or Navx Verismo).

Methods: We performed catheter ablation of PAF in 52 pts (42 males, mean age 56 ± 11 years). Patients were divided in 3 groups: segmental PVI with decapolar ring catheter (group A, 19 pts); antral PVI using a combined technique with decapolar ring catheter/CartoMerge™ (group B, 25 pts) or Navx Verismo (group C, 8 pts). All patients had Holter-ECG follow-up at 3, 6, 12 months.

Results: A complete PVI was achieved in 74% in group A, 82% in group B and 100% in group C. After a 19 ± 17 months mean follow-up, overall arrhythmia free survival was 79% at 1 year, 79% in group A, 78% in group B and 86% in group C, with no statistically significant differences.

Conclusions: PVI plays a major role in paroxysmal atrial fibrillation ablation efficacy. The combined approach did not show a higher rate of complete PVI.

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15.6 UTILITY AND SAFETY OF MESH MAPPER CATHETER FOR PULMONARY VEIN DISCONNECTION IN PAROXYSMAL ATRIAL FIBRILLATION

*A. Sparagna, *A. Dello Russo, *M. Casella, *G. Pelargonio, *M.L. Narducci, *R. Biddau, *G. Bencardino, *C. Bisceglia, *M.T. Lucciola, *P. Zecchi, *F. Bellocci *Catholic University of Sacred Heart, Department of Cardiovascular Medicine, Institute of Cardiology, Rome, Italy

Introduction: Pulmonary vein (PV) isolation is one of the current strategies in paroxysmal atrial fibrillation (AF) treatment. To improve the detection of PV potentials we evaluated the utility and safety of a new high-density mapping catheter during AF ablation.

Methods: three patients with drug-refractory paroxysmal AF underwent PV isolation. The electrophysiological endpoint was the complete disconnection of each vein, first assessed with standard circular catheter and then with a 32-poles HD Mesh Mapper catheter (Bard, USA). All the PV ostia except one (RIPV) were mapped with Mesh catheter.

Results: all veins appeared disconnected with standard circular catheter, but the Mesh catheter showed presence of venous potentials in 4 veins (2 LSPV, 1 RSPV, 1 LIPV). The PV isolation was completed with additional RF pulses. There were no adverse events.

Conclusions: The mesh mapper catheter allowed a stable mapping of the PV ostium, consequently allowing the complete disconnection of each vein.

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15.7 ISOLATION OF PULMONARY VEIN WITH A NOVEL MESH CATHETER DELIVERING PULSED RADIOFREQUENCY

*P. De Filippo, **S. Giovannoni, *M.V. La Grotta, *A. Gavazzi, *F. Cantù *O.O.R.R. Bergamo, Bergamo, Italy **Bard, Italy

Introduction and Methods: Pulmonary veins (PV) isolation is the standard interventional approach for paroxysmal atrial fibrillation (AF) and the first step in the ablation of persistent AF. The MESH ablator is a new device able to record bipolar signal and deliver pulsed radiofrequency (RF) from a circular band of poles. The purpose of this study is to determine the safety and efficacy of MESH ablator for PV isolation.

Results: In five patients with paroxysmal (three) persistent (two) AF, PV isolation was performed with the MESH ablator. The left superior, left inferior and right superior were targeted in all patients, and the right inferior PV was isolated in three patients. Eighteen of 18 (100%) targeted PVs were isolated with a mean of xx±xx min of pulsed RF energy applied at a maximum power of 100 W under a temperature control of four thermocouples. Within a 30 minute check no PV recovery was observed. Complications were absent in all patients.

Conclusions: From this preliminary data, MESH ablator is a safe and efficacious device for PV isolation that may significantly improve the efficiency of this procedure.

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Thumbnail image of graphical abstract

Figure. 

15.8 COMPARISON OF TWO METHODS FOR IDENTIFYING COMPLEX FRACTIONATED ATRIAL ELECTROGRAMS

*D. Wichterle, *V. Kremen, *R. Cihak, *J. Kautzner *Institute for Clinical and Experimental Medicine, Prague, Czech Republic

Introduction: Complex fractionated atrial electrograms (CFAEs) represent the electrophysiologic substrate for atrial fibrillation (AF). Progress in signal processing algorithms for identifying CFAE sites is crucial for the development of AF ablation strategies.

Methods: We compared two methods for discriminating atrial electrograms (A-EGMs) with different degree of fractionation. The first method (M1) assessed the average interval between discrete A-EGM spikes detected based on peak-to-peak voltage sensitivity, signal width and refractory interval criteria (algorithm previously implemented in commercially available mapping system). The second method (M2) employed the simple non-parametric description of distribution of peak-to-peak signal differences. Head-to-head comparison of both methods was performed using a representative set of 1.5 s A-EGMs (n = 113) ranked by an expert into 4 categories: 1 – organized atrial activity; 2 – mild; 3 – intermediate; 4 – high degree of fractionation.

Results: Although input parameters of M1 method were carefully optimized with respect to a particular experimental dataset, the discriminative power of M1 method to detect CFAEs was inferior to that provided by the newly introduced M2 algorithm. Correlations between A-EGM categories and M1 and M2 indices of fractionation are shown in the Figure.

Conclusions: The novel method of A-EGMs classification offers robust and operator-independent definition of electrogram complexity. It may easily be incorporated into real-time mapping systems to facilitate CFAE identification and guide the AF substrate ablation.

image

Figure. 

16. ATRIAL FIBRILLATION ABLATION: IMPACT OF DIFFERENT STRATEGIES AND CATHETER TECHNOLOGY

16.1 A NEW ANATOMICAL APPROACH TO THE TREATMENT OF ATRIAL FIBRILLATION: CATHETER ABLATION OF LEFT ATRIAL GANGLIONATED PLEXI

*E. Pokushalov, *A. Turov, *P. Shugayev, *S. Artyomenko *State Research Institute of Circulation Pathology, Novosibirsk, Russia

Introduction: Radiofrequency ablation (RF) of pulmonary vein ostia does not provide for the complete and long-term elimination of atrial fibrillation (AF). Combining this procedure with local radiofrequency (RF) applications on sites with strong vagal reflexes results in partial parasympathetic denervation and increases the anti-arrhythmic effect. However, ablation intended only to create vegetative denervation of the left atrium (LA) has not yet been used in medical practice and its effect is unknown.

Methods: The study included 58 patients (mean age, 52.1 ± 1.9 years; men, 67.2%) with drug-refractory AF. The disease was chronic in 21 patients (36.2%; mean duration of 14.3 ± 2.9 months; range, from five to 39 months). The mean left atrial volume was 93.1 ± 6.1 mL. The patients underwent an ablation of four GP areas (GP-ablation) in the left atrium with no circumferential ablation of pulmonary veins.

Results: Intra-operational AF termination effect was observed in 94.1% of the cases. Vagal bradycardia was seen in 93% of the cases (4.3 ± 0.9 episodes per procedure). During 7.2 ± 0.4 months after the procedure, 86.2% of the patients were free from arrhythmia and no antiarrhythmic drugs (AAD) were administered. After the RF ablation, SDNN, rMSSD and HF variables were decreased, while HRmin, HRmean and LF/HF variables were increased. Patients with AF relapses had higher SDNN values (97.5 +− 22.3 and 79.3 +− 27.8 ms < 0.001) and less pronounced vagal reflexes during ablation (2.3 +− 1.1 and 4.8 +− 0.8 episodes respectively, p < 0.01).

Conclusions: GP-ablation is a novel and efficient approach within the field of treatment of AF. Vagal bradycardia intensity during RF ablation and the degree of autonomic HRV modification after a procedure are important predictors of the subsequent clinical effect.

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16.2 BACKGROUND TACHYCARDIA AND AF-NEST ABLATION. NEW ASPECTS OF ATRIAL FIBRILLATION PHYSIOPATHOLOGY AND SPECTRAL ABLATION

*J.C. Pachon M, *E.I. Pachon, *T.J. Lobo, *M.Z.C. Pachon, *J.C. Pachon, *R.N.A. Vargas, *L.S. Piegas, *A.D. Jatene *Sao Paulo Heart Hospital-HCor & Dante Pazzanese Cardiology Institute, Sao Paulo, Brazil

Introduction: Using spectral mapping (SM) in sinus rhythm (SR), we found 2 kinds of atrial myocardium: the compact form, with a smooth spectrum, and the fibrillar form, with a segmented spectrum (AF-Nest-[AFN]). During AF, AFN displayed a highly disorganized frequency-[resonant], while the compact form had a lower, well-organized frequency [passive]. AFN resonance re-feeds the AF. On ablating the AFN during AF, we observed a residual regular fast tachycardia with entry block: background tachycardia-(BT). We describe BT and its role in AF physiopathology and ablation.

Methods: Ninety refractory patients (AFp, 51 ± 12 yrs) were studied. AFN catheter RF-ablation [4/8 mm-60°/30 J/30 s] by SM in SR outside PV. BT induction by fast atrial pacing after SR AFN ablation. BT ablation(G1) or reversion(G2).

Results: Forty-seven BT (52%) were found: 18 treated by focal ablation (G1) and 29 reverted (G2). BT features: protected micro-reentry, high frequency: 256 ± 34 bpm, difficult induction and very difficult reversion by pacing. AF/BT recurrence(10 ± 6 m): G1-5.5%× 27%-G2, p < 0.01.

Conclusions: Overt AF is caused by at least one BT+AFN resonance. Entry block protects the BT, preventing its reversion. BT high frequency keeps AFN resonating. AFN ablation enables BT to be induced/visualized. BT should be ablated in order to increase the success of AF ablation.

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16.3 OUTCOME OF A NEW AF MAPPING AND ABLATION APPROACH PROVIDING IMPROVED CATHETER NAVIGATION, CATHETER STABILITY AND LA WALL CONTACT

*S. Kircher, †C. Piorkowski, *H. Kottkamp, *P. Sommer, *J.H. Gerds-Li, *G. Hindricks †Department of Cardiology/Electrophysiology, Leipzig, Germany *University Leipzig, Heart Center, Leipzig, Germany

Introduction: Lack of stable access to ablation sites is one major limitation for the efficacy of LA pulmonary vein (PV) ablation.

Methods: In this case-control analysis, 245 patients treated with conventional PV ablation were matched with 105 patients ablated with a similar line concept, although mapping and ablation were performed with a steerable sheath catheter navigation. Finally, 166 patients were selected to be included in 83 matched pairs. Success rate (freedom from AF) was measured by serial 7-day Holter ECGs.

Results: Using steerable sheaths increased the success rate from 56% to 77% (p = 0.026). The rate of re-ablations was reduced from 28% to 7% (p = 0.0001). No differences were found concerning procedure time, fluoroscopy time, irradiation dose, radiofrequency burning time and complication rate.

Conclusions: An AF mapping and ablation approach using a steerable sheath for catheter navigation improved the outcome at similar intervention times.

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16.4 EFFECTS OF SERUM IRRIGATION RADIOFREQUENCY ABLATION TECHNIQUE ON ATRIAL NATRIURETIC PEPTIDE AND HEMODYNAMICS

*H. Ustunsoy, *C. Kayiran, *M.A. Celkan, *H. Kazaz, *O. Burma *Gaziantep University, School of Medicine, Cardiovascular Surgery Department, Gaziantep, Turkey

Introduction: In recent years, serum irrigation radiofrequency ablation technique has been used for the surgical treatment of atrial fibrillation (AF) with 80–90% efficiency. The effects of SIRFA technique on atrial natriuretic peptides and hemodynamics were investigated.

Methods: Between May 2005 and April 2006, 22 patients (15 females, 7 males) who underwent SIRFA (Cardioblate TM. Medtronic Minneapolis, USA) treatment and 30 patients (19 females, 11 males average) with normal sinus rhythm who did not undergo the SIRFA treatment were accepted to our hospital for the study. Their effort capabilities were classified according to the New York Heart Association. Patients’ pre-operative and post-operative plasma atrial natriuretic peptide (ANP) levels were measured. Plasma ANP and hemodynamic parameters were compared to those of the control group. Early post-operative transthoratic echocardiographic parameters were compared. Mann-Whitney U, chi-square or Fisher's exact tests were performed for statistical analysis.

Results: Post-operative plasma ANP level was found to remain high in the test group and plasma levels tended to rise on the fifth day. Other than right atrium in the second post operative day and urine output in the first day, no other significant differences were detected in hemodynamic parameters. TTEko comparison revealed a significant difference in the mitral valve gradient for the test group.

Conclusions: Along with its effectiveness in AF surgery, serum irrigation radiofrequency ablation does not have negative effects on plasma ANP levels and hemodynamics in the early post-operative period. Metabolic effects can be also taken into consideration in ANP level follow-ups. Studies that will include mid- and long-term plasma ANP level measurements rather than early period measurements might be more useful.

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16.5 ISOLATION OF THE PULMONARY VEINS WITH CRYOENERGY: RESULTS WITH A SINGLE CRYOBALLOON CATHETER

*H. Neuser, *M. Koller, *St. Fröhner, *M. Schneider, *B. Schumacher *Centre for Cardiovascular Medicine, Department of Cardiology and Department of Radiology, Bad Neustadt/Saale, Germany

Introduction: Pulmonary vein isolation (PVI) is well accepted as ablative therapy in eliminating highly symptomatic atrial fibrillation (AF). Due to potential disadvantages of radiofrequency, a novel ballon-based catheter has been developed using cryoenergy as alternative energy source. Effective ablation with the cryoballoon requires correct positioning at the ostium of each PV. Due to the variant anatomy and the number of the PV, the use of a single device might be insufficient.

Methods: In our study we included a consecutive series of patients with paroxysmal or persistent AF, who were treated with a new percutaneous balloon-based cryothermal ablation catheter (ARCTIC FRONT®, CryoCath Technologies Inc.). The device is available in 2 sizes (23 or 28 mm diameter). The balloon selection was based on the anatomy of the PV, which could be pre-assessed from 3D reconstructions of magnetic resonance angiography or spiral computed tomography. Isolation of the PV was proved with a multipolar LASSO catheter.

Results: During a period of 8 months 42 pts (32 m; 56.6 ± 11.3 y) underwent cryothermal ablation for AF. The diameter for the PV were 15.3 ± 7.2 mm (right superior PV), 13.9 ± 6.9 mm (right inferior PV), 14.8 ± 7.6 mm (left superior PV), 12.7 ± 6.2 mm (left inferior PV). In 12 pts accessory PV were found (mean diameter: 6.7 ± 2.9 mm), 4 pts demonstrated a common ostium (3 left-sided PV: diameter 26.1 ± 1.5 mm; 1 right-sided PV: diameter 25 mm). Cryoenergy was applied with a single 28 mm balloon in 26 pts and with a 23 mm balloon in 13 pts, and both balloon types were used in 3 pts. In 2 of these pts the 28 mm balloon was selected as first-line device, and in 1 pt there was a crossover from the 23- to the 28 mm balloon. In 39/42 pts a complete isolation of all veins could be achieved; in 3 pts we found three PV isolated.

Conclusions: Preoperatively aquired CT or MR images provide detailed information about the number and the anatomy of pulmonary veins. This is helpful for selecting the best suitable device in cryothermal ablation for pts with atrial fibrillation. In a large majority the procedure can be effectively performed with a single cryoballoon. This may improve efficacy and reduce procedure time and costs.

Table 1.  Univariate analysis for comparisons between procedural and clinical data of CONVENTIONAL group and COOLED group
VariablesGROUP CONVENTIONAL 8 mm catheter N = 86GROUP COOLED Cooled catheter N = 905p
  1. Data are presented in mean terms (SD), unless otherwise indicated.

  2. AF = atrial fibrillation; CTI = cavo-tricuspidalic isthmus; ICE = intracardiac echocardiography; LA = left atrium; PV = pulmonary vein; RF = radiofrequency; REDO = patients who had already undergone PVs RF catheter ablation; TEE = transesophageal echocardiography.

Male gender (%)77.973.70.4
Age (years)60.7 (10.7)57.8 (10)0.01
Duration of AF History (years)1.2 (1.8)4.9 (4.1)0.000
Left atrial size (mm)33.4 (10.5)44.1 (6.2)0.000
Left ventricle ejection fraction (%)48 (8.6)57.5 (6.6)0.000
Persistent/permanent AF (%)27.941.20.01
History of cerebrovascular accident (%)3.814.50.002
Arterial hypertension (%)18.934.30.002
Valvular heart disease (%)5.87.20.6
Coronary artery disease (%)9.38.30.7
Dilated cardiomyopathy (%)11.6200.06
Tridimensional mapping technique10097.40.8
Pre-procedural TEE (%)25.675.70.000
“REDO” patients (%)7.014.30.058
CTI ablation (%)83.770.30.008
LA Roof linear ablation added (%)3.529.60.000
Duration of RF delivery (minutes)43.1 (9.2)42.7 (15.3)0.8
Duration of procedure (minutes)85.2 (58)207.2 (70.8)0.000
Fluoroscopy time (minutes)15.6 (12)36.5 (20.1)0.000
Learning curve level (<50 procedures) (%)59.311.20.000

16.6 OPEN IRRIGATED VERSUS CONVENTIONAL LARGE TIP CATHETER IN ATRIAL FIBRILLATION ABLATION IMPACT ON PROCEDURAL SAFETY

F. Zoppo, E. Bertaglia, *C. Tondo, **A. Coltella, ***R. Mantovan, ****G. Senatore, †N. Bottoni, ††G. Carreras, †††L. Corò, ††††P. Turco, ‡M. Mantica, ‡‡G. Stabile Multicenter Prospective Italian Observational Registry on Atrial Fibrillation Ablation Procedural Safety, Cardiology Department of Ospedale Civile Mirano, Venice ; *Ospedale San Camillo, Rome ; **Ospedale Careggi, Florence ; ***Ospedale Ca’ Foncello, Treviso ; ****Ospedale Civile di Ciriè, Turin ; †Ospedale Civile Santa Maria Nuova, Reggio Emilia ; ††Ospedale Santa Maria di Loreto, Naples ; †††Ospedale Civile di Conegliano, Treviso ; ††††Casa di Cura Villa Maria Cecilia, Cotignola, Ravenna ; ‡Ospedale Sant’Ambrogio, Milan ; ‡‡Casa di Cura San Michele, Maddaloni, Caserta; Italy

Introduction: The question of whether cooling catheters should be preferred in left atrium (LA) ablation during atrial fibrillation (AF) is not yet defined. Data are available on efficacy, whereas there are no consistent data concerning safety.

Methods: From April 2005 to October 2006, 991 (74% males) consecutive pts were prospectively collected for AF ablation in 10 Italian centres. Electroanatomic mapping was used in 80% of cases. Not cooled large 8 mm tip catheter was used in 86 patients (pts) (9% conventional group) and cooled tip catheter in 905 pts (91% cooled group).

Results: The mean age of the conventional group was 60.7 +− 10.7, vs cooled group 57.8 +− 10 (p = 0.01). Cooled group patients had a longer history of AF (4.9 +− 4.1 vs 1.2 +− 1.8 years, p = 0.000), a previous history of cerebrovascular accident (14.5 vs 3.8%, p = 0.002), were most often affected by long lasting permanent or persistent AF (41.2 vs 27.9%, p = 0.01), had a larger LA size (44.1 +− 6.2 versus 33.4 +− 10.5 mm; p = <0.0000) and had most frequently arterial hypertension (34.3 versus 18.9%; p = 0.002). Moreover they underwent a longer procedure (207.2 +− 70.8 vs 85.2. +− 58 min), with longer fluoroscopy time (36.5 +− 20.1 vs 15.6 +− 12 min; p = <0.0000 for both). The conventional tip was found to be most often used in less experienced laboratories (59.3% vs 11.2%% of use in laboratories with less than 50 procedures already performed). Besides, ablation strategy was significantly different: linear lesions at LA roof, to substrate modification were added more frequently in the cooled group (29.6 vs 3.5%%; p < 0.000). The cumulative complications rate of the entire study population was 4%. Cerebral thromboembolism, pulmonary veins stenosis,

Table 2.  Univariate analysis for comparisons between complications of CONVENTIONAL group and COOLED group
VariablesCONVENTIONAL GROUP 8 mm catheter N = 86COOLED GROUP Cooled catheter N = 905p
Pericardial effusions/tamponade (cumulative rate 1.3%)1.21.51.0
Pulmonary veins stenosys (cumulative rate 0.4%)00.51
Cerebral embolism (cumulative rate 0.4%)00.41
Cumulative complication rate (cumulative rate 4%)4.73.80.7
Vascular groin complications (cumulative rate 2%)4.72.00.10

pericardial effusions, cardiac tamponade and groin vascular complications rates were 0.5%, 0.4%, 0.8%, 0.6% and 2% respectively. In the unvaried comparison for such complications occurring, no difference was found between the two study groups. Among the clinical and procedural covariates subjected to further multivariate model (logistic regression), a longer procedure time (OR 1.018, CI 95% 1.009 to 1.027; p = 0.000), a longer history of AF (OR 1.311, CI 95% 1.063 to 1.616; p = 0.01), and the presence of a previous anamnestic cerebrovascular accident (OR 4.394, CI 95% 1.202 to 16.065; p = 0.02) characterised the patients treated with irrigated tip catheter which underwent a more complex procedure not limited to PV isolation but even oriented to substrate modification with linear lesions at LA roof added (OR 16.847, CI 95% 4.288 to 66.190; p = 0.000).

Conclusions: In the present registry both systems of catheter ablation showed a similar safety procedural profile. The irrigated system was most often used in more experienced laboratories and in patients with clinical surrogates of atrial electric and anatomical remodelling such as long lasting AF with larger LA sizes, therefore justifying longer times in more complex procedures not limited to PV isolation.

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16.7 HIGH SUCCESS RATE IN CRYOISOLATION OF PULMONARY VEIN OSTIA AND ANTRUM WITH THE NEW 28/23 MM BALLOON IN PAROXYSMAL ATRIAL FIBRILLATION

*J. Vogt, *A. Dorszewski, *J. Heintze, *U. Scholz, *H. Buschler, *L. Luong Thanh, *D. Horstkotte *Department of Cardiology, Heart and Diabetes Center North Rhine-Westphalia, Ruhr, Germany University Bochum, Bad Oeynhausen, Germany

Introduction: In the treatment of paroxysmal atrial fibrillation (AF), circumferential substrate modification of the antrum of pulmonary veins (PV) seems to be superior to segmental methods. However, radiofrequency energy carries a risk of PV stenoses and esophago – left atrial fistula. This study reports the success rate in isolating PV ostia and parts of the antrum by means of the cryoballoon technique.

Methods: After PV angiography, isolation was performed with the best-fitting 28/23 mm balloon (Arctic Front, Cryocath, Canada). The wire balloon occludes the venous ostium and parts of the venous antrum, and freezes down to −50 to −75°C for 6 minutes, twice per vein, with nitrous oxide. Lasso mapped rest potentials were eliminated by means of additional balloon freezes or the 9 French Freezer Max catheter. Patients were examined for three months through 7 day-Holter monitoring.

Results: We treated 94 pts (30 women, mean age 59 ± 10 years: 84 with paroxysmal, 10 persistent AF – left atrium 42 ± 4 mm – 41 with lone AF, 37 hypertension, 16 mild structural heart disease) with 23/28 mm balloons. The mean vein diameter was 18.9 ± 4 mm angiographically. With a mean number of 2.4 ± 0.6 impulses, we increased PV isolation up to 93% of the left PV and the right upper PV, and to 84% of the right lower PV and 60% of all 4 PV by means of balloon only. After adjusting the remaining potentials, we isolated 100% of all PV. The duration of the procedure was 195 ± 36 min, the x ray burden 36 ± 9 min. We observed phrenic nerve palsy in 4 pts treated with the 23 mm balloon; these recovered within 6 months. During a mean follow-up of 6 months and 1.1 procedures per pt (8 redos) in 58 pts controlled by means of serial 7-day Holter and symptoms, 77% (39 p) were free of AF without blanking time! 29% (17 p) showed marked reduction in AF burden. In the 8 redos, 76% (16) of the 21 reconducting veins were initially isolated with the 28 mm balloon.

Conclusions: Cryoisolation of ostia and antrum of the PV by means of the 23/28 mm balloon is safe and showed a favourable outcome. Its superiority over substrate modification by means of RF suggests that it could be an early, first-line therapy for left atrial disease. Avoiding phrenic nerve lesions and focusing on the differential efficacy of balloon diameter may be essential.

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16.8 PULMONARY VEIN ISOLATION WITH BALLOON-BASED CRYOENERGY: IS THERE A RISK FOR THE CORONARY ARTERIES?

*H. Neuser, *M. Schneider, *St. Fröhner, *M. Koller, *B. Schumacher *Centre for Cardiovascular Medicine, Department of Cardiology and Department of Radiology, Bad Neustadt/Saale, Germany

Introduction: Pulmonary vein isolation (PVI) is widely accepted as a curative technique for the treatment of patients (pts) with highly symptomatic atrial fibrillation (AF). Due to potential disadvantages of radiofrequency, new alternative energy sources have been developed. Novel balloon-based cryogenic catheter systems may improve the success rate of AF ablation achieving more transmural and deeper lesions, but increases the concern about cryo-induced damage of the adjacent structures such as the coronary arteries.

Methods: We report our first experience with a new percutaneous balloon-based cryothermal ablation catheter (ARCTIC FRONT®, CryoCath Technologies Inc.), which was used for ostial PVI in paroxysmal AF. During application of the cryoenergy at the left-sided PV, we performed a simultaneous angiography of the left coronary artery. 3 ± 1 h and 12 ± 6 h after the procedure, the myocardial enzymes (CK, troponin) were measured, together with a 12-lead ECG at this time.

Results: During a period of 6 months 45 pts (34 m, 11 f; mean age 56.2 y) underwent a cryothermal ablation for AF. The anatomy of the PV was assessed using 3D reconstructions of magnetic resonance angiography or spiral computed tomography. Cryoenergy was applied with a 28 mm balloon in 29 pts and with a 23 mm balloon in 13 pts; both balloon types were used in 3 pts. A relevant coronary artery disease had been excluded before ablation either by angiography (14 pts) or by non-invasive exercise tests. In 35/45 pts the result of cryoablation was documented by mapping the PV ostia with a multipolar LASSO catheter. In 32/35 pts a complete isolation of all veins could be achieved; in 3 pts we found three PV isolated. The coronary angiography during the ablation showed no fixed narrowings or spasms in all 45 pts. Accordingly, we did not find ischaemia- or infarct-related ECG signs or a significant increase in CK or troponin after all of the procedures.

Conclusions: Notwithstanding the neighbourhood of left atrium and left coronary artery and the deepness of cryothermal ablation, we found no myocardial ischaemia or lesion of the adjacent vessels. Even with bigger balloons cryoablation is not associated with damage of the coronary arteries.

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17. ATRIAL FIBRILLATION ABLATION: CLINICAL OUTCOMES

17.1 PREDICTORS OF SUCCESSFUL OUTCOME OF CATHETER ABLATION FOR CHRONIC ATRIAL FIBRILLATION

*M. Fiala, *J. Chovancik, *R. Moravec, *D. Wojnarova, *H. Szymeczek, *R. Neuwirth, *R. Nevralova, *O. Jiravsky, *L. Sknouril, *M. Dorda, *J. Januska, *I. Nykl, *M. Branny *Department of Cardiology, Heart Centre, Hospital Podlesí, Trinec, Czech Republic

Introduction: Predictors of successful ablation of chronic atrial fibrillation (CHFS) were evaluated.

Methods: Ablation of CHAF was performed in 100 patients (pts) (21 F; 55 ± 10 years). Ablation consisted of complex left atrial (LA) and CS ablation. Sinus rhythm (SR) restoration was the procedure within the end-point.

Results: First procedure: SR was restored in 38 pts, 32x via converting LA tachycardia (LAT). Following first ablation, 52 (52%) pts have stable SR. The groups did not differ in age (56 ± 9 vs. 54 ± 12 years), LVEF (%) (53 ± 8 vs. 53 ± 9), LA volume (ml) (156 ± 34 vs. 155 ± 37), or LA volume/BSA (ml/m2) (75 ± 15 vs. 75 ± 15) (acquired from Carto). Pts with SR had shorter CHAF duration (21 ± 18 vs. 33 ± 32 months, P= 0.01), lower proportion of LA points <0.02 mV (Carto) (26 ± 18 vs. 36 ± 21; P < 0.01), and higher proportion of points >1 mV (18 ± 13 vs. 12 ± 10; P= 0.01), and more frequent SR restoration (31 vs. 7 pts, P < 0.001). After re-ablation (34 pts) (F-U 20 ± 13 mo), SR is present in 81 (81%) pts, of whom SR was restored in at least one procedure in 51 (63%) pts, while in none of 19 pts with AF/AT (P< 0.001).

Conclusions: SR restoration by ablation, duration of chronic AF, and higher LA voltage were the major determinants of long-term clinical success.

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17.2 USEFULNESS OF ATRIAL FIBRILLATION BURDEN AND LEFT ATRIAL SIZE AS PREDICTORS FOR OUTCOME AFTER PULMONARY VEIN ISOLATION WITH CRYOBALLOON

*A. Berkowitsch, *S. Zaltsberg, *M. Kuniss, *J. Schmitt, *K. Kurzidim, *J. Sperzel, *C. Hamm, *H.F. Pitschner *Kerckhoff Heart Centre, Dept. of Cardiology, Bad Nauheim, Germany

Introduction: Clinical success of PVI with cryoballoon is under-investigated.

Methods: The aim of this study was to evaluate the usefulness of AF burden (AFB) (total duration of all AF episodes) at baseline and left atrial size (LAS) as predictors for long-term PVI outcome. Fifty-nine patients with paroxysmal AF (37 male, Age: 58: (49–64) y, LVEF: 60 (55–65)%, 38 Hypertension, 4 CAD, AF-duration 72 (29–120) months [the data are given as median and IQR]) were enrolled in the study. AFB prior to ablation was 180 (90–355) hours/3 months. LAS was 53 (48–57) mm measured at a long axis (LA) mm and 38 (36–41) mm measured at a short axis (SA).

Results: The primary endpoint (PE) of the study was first AF recurrence >30 s. The secondary endpoint (SE) was first recurrence amounting to AFB ≥12 hours/3. The first three months after PVI were allowed as a blanking period. During follow-up at 6 (range: 4–24) months, 31 (52.5%) patients had recurrences, 19 (32%) of whom reached SE. The multivariate analysis revealed AFB and LA to be independent predictors for the PE (p < .02 for both) and for the SE (p < .001 for both). After performing ROC-curve-analysis, AFB and LA were dichotomized on 500 hours and on 60 mm, respectively. The PPA of AFB ≥ 500 h was 87.5% for PE and SE. The NPA was 53% and 76.5% respectively. The PPA and NPA of LA ≥ 60 mm were 70% and 51% for PE and 60% and 73.5% for SE.

Conclusions: This study demonstrated that assessment of AF burden and LAS at baseline helps estimate clinical success probability after PVI with cryoballoon.

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17.3 IMPROVEMENT OF PATIENTS WITH IMPAIRED LEFT VENTRICULAR FUNCTION AFTER PULMONARY VEIN ISOLATION: EVALUATION OF LEFT VENTRICULAR EJECTION FRACTION IN MAGNETIC RESONANCE IMAGING

*B. Lutomsky, *A. Koops, *D. Ueberschaer, *T. Plagemann, *R. Ventura, *T. Rostock, *T. Risius, *D. Steven, *S. Willems *Cardiac Centre, Department of Cardiology, University Hospital Hamburg-Eppendorf, Hamburg, Germany

Introduction: Pulmonary vein isolation (PVI) is a safe and effective treatment in patients with paroxysmal atrial fibrillation (PAF) and mainly performed in patients without structural heart disease. A beneficial effect of PVI has been demonstrated in patients with congestive heart failure and impaired left ventricular function (LVEF). However, the different impact of PVI on cardiac function in patients with mild and significant impaired LVEF has not yet been proven.

Methods: Seventy patients with PAF were scanned on a 1.5-T MRI and 6 months after PVI during sinus rhythm. Enddiastolic volume (EDV), endsystolic volume (ESV) and LVEF were determined and shortening fraction (SF) was calculated. Patients were categorized into two groups regarding cardiac function prior to the procedure assessed by MRI: group 1 (n = 18) – patients with a LVEF <50% and group 2 (n = 52) – patients with a LVEF >50%. All patients underwent PVI of all pulmonary veins and atrial defragmentation in case of persistent inducibility of AF after PVI.

Results: MRI in group 1 patients revealed a significant improvement in cardiac function after AF ablation (41.3 ± 6.5% vs. 51.5 ± 12.3%, P = 0.004) whereas group 2 patients did not show an improved LVEF (60.4 ± 6.1% vs. 58.6 ± 9.2%, P = 0.22) after a follow-up period of 6 months.

Conclusions: Catheter ablation of AF improves cardiac function in patients with PAF and mildly to moderately impaired LVEF. However, patients with normal LVEF and an ejection fraction >50% do not benefit from an AF ablation procedure regarding left ventricular function. These data suggest that minor degrees of depression of cardiac function are less likely to be caused by the existence of PAF and are therefore less likely to be influenced by the elimination of it.

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17.4 EARLY RECURRENCES OF ATRIAL FIBRILLATION AFTER CATHETER ABLATION: IMPORTANCE FOR LONG TERM ARRHYTHMIA CONTROL

*E.B. Saad, *F. Ferriera, *I.P. Costa, *F. Veronese, *P. Maldonado, *L.E. Camanho *Cardiac Arrhythmia Service, Center for Atrial Fibrillation, Hospital Pró-Cardíaco, Rio de Janeiro, Brazil

Introduction: Early recurrence of atrial fibrillation (AF) after catheter ablation is currently considered a transient phenomenon with no implications for long-term arrhythmia control. The present study assessed whether early recurrences of AF after ablation (< 6 weeks) could predict AF recurrences during long-term follow-up after catheter ablation.

Methods: 121 pts (mean age 64 ± 10 years, 28 (23%) female) with recurrent AF refractory to at least 2 anti-arrhythmic drugs for 4 ± 3 years. Mean left atrial size and LV ejection fraction were 4.4 ± 0.6 cm and 52 ± 4%, respectively. 33 pts (28%) had significant structural heart disease; 77 pts (63%) presented with paroxysmal AF, 34 (28%) with persistent AF and 11 (9%) with permanent AF. Extensive LA lesions were created by means of an 8 mm tip catheter, the power being controlled on the basis of micro-bubble formation as visualized by ICE. PV antrum isolation was confirmed by using a decapolar circular mapping catheter.

Results: After 21 months of follow-up, late recurrences were documented in 25 pts (20%). Early recurrences occurred in 37 pts (30%). Of these, 19 (51%) also had late recurrences. No procedure-related complications were observed in the population studied.

Conclusions: Early recurrences (< 6 weeks) of AF after pulmonary vein atrum isolation are associated with a high risk of arrhythmia recurrence. In the event of early AF recurrence, the patient should be closely monitored for subsequent AF recurrences, and the use of anticoagulation therapy should be prolonged after an apparently successful catheter ablation procedure.

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17.5 NEW INSIGHTS INTO LONG-TERM FOLLOW UP OF ATRIAL FIBRILLATION: FULL DISCLOSURE BY AN IMPLANTABLE PACEMAKER DEVICE

†M. Martinek, †J. Aichinger, †H.J. Nesser, *P.D. Ziegler, †H. Purerfellner †Department of Cardiology, Public Hospital Elisabethinen, Academic Teaching Hospital, Linz, Austria *Medtronic Inc., Minneapolis, USA

Introduction: This study sought to evaluate various aspects of very long-term follow ups (FU) through the properties of an implantable device.

Methods: Fourteen patients with an implanted pacemaker device (Medtronic AT500) were selected for radiofrequency catheter ablation (RFA).

Results: With a mean FU of 41.4 ± 15.1 months we could achieve continuous monitoring for more than 400,000 hours after RFA. Based on symptomatic episodes, simulated every 24 hours, 48 hours or 7-day Holter, 57–71% of patients were classified as RFA responders. With permanent FU provided by the implanted device, 43% exhibited a positive treatment effect and only 21% had no tachyarrhythmic episode at all. With a mean of 1.7 ± 0.7 RFA per subject, atrial tachyarrhythmia burden (ATB) was significantly reduced from a median of 3.6 to 0.3 hours per day (p < 0.001). Two out of 14 patients developed AF recurrences after a tachyarrhythmia-free period of more than 12 months.

Conclusions: ATB is decreased significantly by (repeated) RFA over a very long-term FU. Continuous monitoring provided by an implantable device is able to detect more AF episodes than routine FU. AF may reoccur after long-lasting episode-free intervals.

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17.6 PREVALENCE OF PULMONARY VENOUS POTENTIALS AFTER CATHETER ABLATION OF ATRIAL FIBRILLATION: A PROBABLE MECHANISM FOR ARRHYTHMIA RECURRENCE

*E.B. Saad, *F. Ferreira, *I.P. Costa, *F. Veronese, *P. Maldonado, *L.E. Camanho *Cardiac Arrhythmia Service, Centre for Atrial Fibrillation, Hospital Pró-Cardíaco, Rio de Janeiro, Brazil

Introduction: Circumferential ablation around the pulmonary veins (PV) is the most commonly performed procedure for treatment of drug-refractory atrial fibrillation (AF). Depending on the technique utilized, the PVs are isolated from the left atrium (LA). Arrhythmia recurrence may be related to persistence or recurrence of PV potentials at sites previously ablated. Herein is described the prevalence of PV potentials in pts presenting for a second procedure with recurrence of AF after an initial catheter ablation procedure.

Methods and Results: 120 pts underwent AF ablation using the PV antrum isolation technique guided by intracardiac echocardiography (ICE). 100% had documented isolation of all PVs. 7 pts (6%– group I) underwent a second procedure using the same technique (2 female (29%), 5 with paroxysmal AF (71%), 1 with persistent AF (15%) and 1 with permanent AF (15%)). All pts had PV potentials at the right inferior PV, 4 (57%) had potentials at the right superior PV, 2 (29%) at the left superior PV and 2 (29%) at the left inferior PV (mean 2.2 ± 0.7 PVs with potentials/pt). A second procedure using the PV antrum isolation technique and ICE was also performed in 8 pts who had previously undergone ablation guided by electroanatomical landmarks (Group II). PV potentials were found in all pts; 6 pts (75%) had potentials in all PVs. Isolation was found in the left inferior PV in 1 pt and the left superior PV in 1 pt (mean 3.5 ± 0.3 PVs with potentials/pt; p = 0.0034 Chi2). A total of 15 pts underwent a second procedure with PV isolation; after a mean follow up of 12 months, 13 (87%) are AF-free without the use of drugs.

Conclusions: PV reconnection is frequently observed in pts presenting for a second procedure for AF ablation. The good clinical response to PV isolation after the redo procedure suggests that lack of isolation is an important mechanism of recurrence.

  1. #: number of PVs whose parameter was measurable. Values expressed as median and (IQR).

LA-PV SR (#38)1:1 PV-LA (#15)ERP (#38)FRP (#38)ΔPV-LAmax/PV-LAb (#38)
62 (40–80) ms190 (160–220) ms155 (125–180) ms187 (158–220) ms88 (55–110) ms

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17.7 ELECTROPHYSIOLOGICAL PROPERTIES OF PULMONARY VEINS WITH LATE CONDUCTION RECOVERY AFTER ELECTRICAL ISOLATION

†P. Moretti, †M. Tritto, †G. Spadacini, *L. Di Biase, †M. Dulbecco, *R. Bai, *J.A. Salerno-Uriarte †Istituto Clinico Mater Domini, Castellana, Varese, Italy *Dipartimento di Scienze Cardiovascolari, Università dell’Insubria, Varese, Italy

Introduction: Late left atrial (LA) to pulmonary vein (PV) conduction recovery is common after PV electrical isolation, however, the electrical properties (EPs) of re-conducting (RECO) PV have not yet been fully investigated. We prospectively evaluated the EPs of RECO PVs in 22 consecutive patients (pts) (three female, mean age: 55 ± 11 yrs) with drug-refractory atrial fibrillation (AF; 13 pts paroxysmal) undergoing repeat PV electrical isolation (9 ± 11 months after the first procedure).

Methods: LA-PV re-conduction was assessed by multielectrode catheters (64 pole “basket”: two pts, 20 pole “lasso”: 20 pts) inserted into previously isolated PVs. In RECO PVs, decremental and premature electrical stimulation (S1S2; 400 ms basic drive cycle length; pacing output at twice the pacing threshold) was performed from a couple of electrodes of the reference catheter. The following parameters were evaluated: 1) LA-PV conduction time in sinus rhythm (LA-PV SR); 2) PV-LA 1:1 conduction (1:1 PV-LA); 3) PV effective (E) and functional (F) refractory periods (RPs); 4) the difference between maximum and baseline PV-LA conduction time evaluated on the reference catheter during extra-stimulation and basic drive, respectively (ΔPV-LAmax/PV-LAb); and, 5) AF induction by electrical stimulation.

Results: LA-PV conduction recovery occurred in 39/61 (64%) previously isolated PVs. The EPs (Tab) were measured in 38/39 PVs (incessant AF starts from one PV after each cardioversion), and AF was inducible in 30/38 (79%) PVs. EPs did not differ according to PV distribution or AF presentation (paroxysmal vs. persistent), but vulnerable PVs had significantly shorter median ERP [150 (IQR: 120–160) ms vs. 180 (IQR: 170–205) ms; p: 0.006] and longer median ΔPV-LAmax/PV-LAb [92 (IQR: 60–134) ms vs. 52 (IQR: 32–75) ms; p: 0.012].

Conclusions: In pts with recurrent AF after PV electrical isolation, RECO PVs have very short RPs, fast and decremental PV-LA conduction capabilities, and marked vulnerability to programmed stimulation. These EPs are similar to those reported during electrophysiological evaluation before PV ablation and they highlight the role of LA-PV conduction recovery in AF recurrence after PV electrical isolation.

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17.8 PROXIMAL CORONARY SINUS AS A CRITICAL PART OF ATRIAL FLUTTER DURING RE-DO ABLATION OF ATRIAL FIBRILLATION PATIENTS

*A.V. Ardashev, *E.G. Zhelyakov, *D.A. Mangutov, *A.V. Konev *Burdenko Head Clinical Hospital, Moscow, Russia

Introduction: The study assesses the role of coronary sinus (CS) as a component of atypical atrial flutter (AAF) reentry circuit after radiofrequency ablation (RFA) of atrial fibrillation (AF) in patients (pts).

Methods: The study was conducted on 102 consecutive pts (44 women, 54.3 ± 13.6 years of age) with the paroxysmal (51%), persistent (22%) and chronic (27%) AF who underwent a circumferential radiofrequency ablation (RFA) procedure guided by CARTO system. AAF manifested in 22 (22%) pts after primary RF-ablation session in the period of 23 ± 15 days. Electrical and/or drug cardioversion was effective in 13 pts. Repeated RFA was performed in nine (9%) pts with sustained drug-refractory AAF.

Results: Activation mapping guided by CARTO system revealed reentry circuits (cycle length, 220 and 230 ms) at the vicinity of right pulmonary veins in two pts and atrial perimitral reentry with mean cycle length of 240 ± 15 ms in seven pts. Left mitral isthmus-dependent AAF was verified by entrainment technique and successfully ablated in those seven cases. Distal CS RF-isolation (12–1 to 3 clock on LAO projection) was performed in all cases as the first step without any corresponding cycle length changes of AAF. As a second step AAF was terminated during left mitral ablation in only two pts. As a third step linear RF-lesions from right pulmonary vein ostium to mitral annulus was performed and was found to be associated with an increase of AAF cycle length (from 240 ± 10 ms to 340 ± 20 ms, p<0.001) in five cases. Additional RF-application applied inside the proximal CS roof (fourth-step) terminated AAF in five pts. There was no arrhythmias induction while the control left auricular burst and programmed stimulation. The follow-up was 6.7 ± 2.4 months. There were neither atrial fibrillation nor atrial flutter during the follow-up period observed.

Conclusions: Structures of proximal coronary sinus corresponding to low common pathway insertions could be critical components of reentry circuit in some cases of atypical atrial flutter after RFA within atrial fibrillation pts.

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18. ATRIAL FIBRILLATION ABLATION: COMPLICATIONS

18.1 FREQUENCY OF UNSUSPECTED LUNG PARENCHYMA LESIONS ASSESSED BY CT-ANGIOGRAPHY PERFORMED BEFORE ATRIAL FIBRILLATION ABLATION

*M.T. Lucciola, *M. Casella, *A. Dello Russo, *G. Pelargonio, *R. Biddau, *M.L. Narducci, *A. Sparagna, *C. Bisceglia, *P. Zecchi, *F. Bellocci, *A. Martino, *L. Bonomo, *F. Bellocci, *R. Marano, *C. Liguori, *G. Savino, *M. Politi, *P. Rinaldi *Cardiovascular Department, Catholic University of the Sacred Heart, Rome, Italy

Introduction: AF ablation (AFA) strategies commonly use 3D reconstruction of left atrium with CT-angiography (CTA), which allows evaluation of extra-cardiac structures. We aimed to assess the frequency of unsuspected lung lesions.

Methods: Before AFA, thirty-nine patients (xx males, mean age xx) underwent a thorax CT imaging with i.v. contrast medium administration. All patients underwent a pulmonary vein isolation using CartoMerge image integration system.

Results: At CTA, incidental lung parenchyma lesion was detected in 9/39 (23%) patients. One calcified nodule and 8 non-calcified micro-nodules were found. Three patients (37.5%), with suspected micro-nodules (>8 mm), underwent CT-PET and surgery that consequently confirmed their malignancy being diagnosed as adenocarcinoma. All other micro-nodules showed no modifications over a 3–6 month CT follow-up. After a risky stratification (smoke habit and previous oncological pathology), 6/9 lesions (66.6%) were detected within high risk patients (3 malignant nodules, 1 calcified nodule and 2 micro-nodules) and 3/9 (33.3%) in low risk ones (all showing no growth over follow-up).

Conclusions: CTA can identify lung parenchyma lesions: due to its crucial role for extra-cardiac findings detection, it could be considered as an integration technique for AFA.

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18.2 SEVERE PULMONARY CAPILLARY LEAKAGE AS EARLY MANIFESTATION OF AN ATYPICAL POST CARDIAC INJURY SYNDROME: A NEW COMPLICATION FOLLOWING EXTENSIVE RADIOFREQUENCY ABLATION FOR ATRIAL FIBRILLATION

*T. Arentz, *R. Weber, *J. Minners, *C. Restle, *F.J. Neumann, *D. Kalusche *Rhythmologie, Herz-Zentrum, Bad Krozingen, Germany

Introduction: A variety of ablation techniques has evolved for the treatment of AF, each however also afflicted with serious adverse effects. We describe a new complication after extensive radiofrequency ablation (RF) in the left atrium (LA) for persistent atrial fibrillation (AF).

Methods: Electroanatomic-guided circumferential pulmonary vein (PV) isolation was performed in the adjacent left atrium, if necessary with complementary focal/segmental ablation in the veno-atrial junction (VAJ) until complete electrical PV isolation was achieved. On an individual basis, supplementary RF applications were performed, targeting the maintaining substrate in persistent AF (ablation of complex fractionated potentials, isolation of other thoracic veins and linear left atrial lesions). RF energy was delivered through a 4-mm open-tip irrigated catheter with a maximum of 25–35 W.

Results: 4 patients undergoing extensive RF ablation for persistent AF (2 patients with additional LA substrate modification) developed a systemic inflammatory response syndrome with bilateral pulmonary oedema within 18–48 h after the procedure. No signs of PV stenosis, focal lung injury, LV dysfunction or otherwise cardiac pathology, circulatory failure or an infectious source were evident. All patients had a complete recovery with supportive therapy within 3 to 4 days after the onset of symptoms.

Conclusions: Extensive LA radiofrequency ablation bears the risk of a severe pulmonary oedema in conjunction with an atypical post cardiac injury syndrome (PCIS). Although the precise mechanism of the pulmonary oedema remains elusive, the accompanying inflammatory response strongly favours a specific immunologic reaction induced by extensive RF ablation.

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18.3 MULTI-DETECTOR CT OF PULMONARY VEINS AND LEFT ATRIUM BEFORE AND AFTER RADIOFREQUENCY CATHETER ABLATION OF ATRIAL FIBRILLATION: OUR EXPERIENCE

*G. Piccoli, *F. Toso, *M. Pesavento, *G. Allocca, *L. Rebellato, *M. Del Pin, *D. Gasparini, *A. Proclemer *Cardiology and Radiology Departments, Az. Ospedaliero-Universitaria di Udine, Udine, Italy

Introduction: Pulmonary vein (PV) isolation is a well-established technique for treating atrial fibrillation. Pre- and post-procedural CT is frequently performed to depict anatomy and baseline measurements of PV. The aim of the study is to test the usefulness of CT before and after ablation in detecting anatomical variation, stenosis and changes in left atrium (LA) diameter.

Methods: Fifty consecutive patients, candidates for segmental PV isolation, were prospectively evaluated by 4-channel MDCT; 2 observers interpreted LA and PV images to asses the anatomy and main atrial diameters. Twenty patients underwent post-ablation check after a 6-month follow up.

Results: Anatomic variants of PV were found in 18/50 patients (36%); average LA diameters were 3.9 × 6.2 × 5.2 cm. In the post-ablation group, single PV major stenosis were found in 3 out of 20 patients (15%) and in 3 out of 75 (4%) PV isolated. Only one patient referred effort dyspnoea. After PV isolation average LA diameters were 3.5 × 5.9 × 4.9.

Conclusions: In our experience CT provides precise anatomical assessment relevant for interventional planning and post-PV isolation follow up. Fusion images (CT and Carto Merge) increase usefulness of anatomical data background.

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18.4 THE ROLE OF CORONARY SINUS IN MAINTENANCE OF CHRONIC ATRIAL FIBRILLATION

*M. Fiala, *J. Chovancik, *R. Moravec, *D. Wojnarova, *H. Szymeczek, *R. Neuwirth, *R. Nevralova, *O. Jiravsky, *L. Sknouril, *M. Dorda, *J. Januska, *I. Nykl, *M. Branny *Department of Cardiology, Heart Centre, Hospital Podlesí, Trinec, Czech Republic

Introduction: Coronary sinus (CS) ablation as the last step to restore sinus rhythm (SR) during ablation for primary chronic atrial fibrillation (CHFS) is reported.

Methods: Ablation of CHAF (>6 months, resistant to amiodarone and cardioversion) was performed in 101 patients (pts) (21 F; 55 ± 10 years). Ablation strategy consisted of complex let atrial (LA) and CS ablation. SR restoration was the procedure within the end-point.

Results: In the first ablation, SR was restored in 38 pts, 32x via LA tachycardia (LAT). One and 2 re-ablations were performed in 34 and 6 pts. SR was restored in 26 (74%) pts and 6 pts during the first and second re-ablation. SR was restored in 57 (56%) pts within at least one procedure, of whom in 6 (11%) pts by ablation inside the CS. Three pts had a pair of LATs that were eliminated with a proximal CS ablation (1), lateral CS ablation (1), or successively by both (1); 3 pts had a single LAT that was eliminated by proximal CS ablation. Non-inducibility required partial or full isolation within the proximal to lateral CS segment.

Conclusions: CS ablation with isolation was required in 11% of the pts with SR restoration to eliminate residual LAT during ablation for primary CHFS. LATs were regular and exhibited characteristics of re-entry.

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18.5 SPIRAL-TC EVALUATION OF LA CONTRACTION AFTER SURGICAL ABLATION FOR ATRIAL FIBRILLATION

*A. Barbone, *E. Citterio, *M. Bergonzini, *G. Silvaggio, *F. Settepani, *A. Eusebio, *M. Muretti, *A. Basciu, *D. Ornaghi, *R. Gallotti *Istituto Clinico Humanitas, UO of Cardiothoracic Surgery, Milan, Italy

Introduction: We compared 2 lesion-patterns surgically performed by cryoablation in order to understand which is better in obtaining a higher degree of sinus rhythm (NSR) while sparing most of the LA: “A/U”(completely isolates the LA posterior-wall: “boxing”) and “7”(electrical stimulus allowed within the pulmonary vein: “open-technique”).

Methods: Multi-slice spiral-TC (EKG-triggered acquisition) can finely reproduce the anatomy of cardiac structure and assess the revolutions within the cardiac cycle. We selected 20 patients (10 per lesion-pattern), who underwent LA-ablation for atrial fibrillation. Ten normal subjects without a history of AF were used as controls. Four different distances (LA diameters) were measured for the same patient at the end of the atrial diastole and systole. LA volume was estimated in both systole and diastole.

Results: In none of the 5 parameters considered could we find any difference between the 2 ablation techniques. However, the diameters of the control population were significantly lower than those of the surgery population for every parameter considered.

Conclusions: We found no contraction advantage in preserving the LA posterior-wall by means of a “7” technique. Even after a long follow-up, the LA would never return to normal dimensions and contraction.

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18.6 PERSISTENT IATROGENIC ATRIAL SEPTAL DEFECT AFTER TRANSSEPTAL PUNCTURE: A NEW COMPLICATION AFTER PULMONARY VEIN ISOLATION?

*A. Rillig, *U. Meyerfeldt, *R. Birkemeyer, *M. Kunze, *W. Jung *Department of Cardiology Schwarzwald-Baar-Klinikum, Villingen-Schwenningen, Germany

Introduction: Pulmonary vein isolation (PVI) is widely practised to treat atrial fibrillation. Transseptal access is necessary with one or more transseptal sheaths to perform PVI. In recent studies, a growing problem of persistent iatrogenic atrial septal defects (iASD) has been observed.

Methods and Results: In this prospective study all patients (n = 26) were examined with TEE before, immediately after and at a 3-, 6- and 12-month follow-up period for evaluation of PV-stenosis and iASD in the period from August 2005 to April 2006. All patients underwent PVI with double transseptal puncture. An iASD was observed immediately after PVI in 77% of the patients with a maximum diameter of 1.0 mm. After 3 months the iASD was completely closed in all patients. During the 6-month follow-up period no patient suffered from cerebral or cardiac embolism and no PV-stenosis was detectable.

Conclusions: We found only small iASDs with left to right shunting after PVI. No iASD was observed at the 3-month-follow-up or later. IASD was not associated with a higher rate of embolism or death.

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18.7 HAEMATOTHORAX – ONE OF THE SERIOUS COMPLICATIONS OF ATRIAL FIBRILLATION ABLATION

*Y.M. Xue, *P.Z. Yang, *X.Z. Zhan, *H.T. Liao, *S.H. Wu *Guangdong Provincial People's Hospital, Guangzhou, China Cardiology Department, Guangdong Cardiovascular Institute, Guangzhou, China

Introduction: The aim of this study was to analyze the incidence and causes of haematothorax in patients undergoing atrial fibrillation (AF) ablation.

Methods: We analyzed 247 consecutive patients undergoing AF ablation between 2001 and 2006, including 80 patients having a segmental pulmonary vein isolation operation (SPVI) and 167 patients operated for circumferential pulmonary vein ablation (CPVA). The coronary sinus (CS) electrode was placed via left subclavian vein. Four patients had haematothorax (3 left, 1 right). The procedure consisted of SPVI in 2 patients and CPVA in 2 patients.

Results: The first haematothorax occurred during ablation of the left superior pulmonary vein; the patient died despite undergoing urgent surgery, but the hemorrhagic location was unclear. The other two patients suffering from haematothorax, caused by multiple punctures of the left subclavian vein, within the left side, were cured by surgery (one) and by draining the pleural effusion (one). The right haematothorax in a patient with a history of mitral valve replacement may be related to errhysis caused by ablation at the right superior pulmonary vein.

Conclusions: Haematothorax is a serious complication of AF ablation. Placing the CS electrode via a femoral vein may greatly reduce the risk.

18.8 CATHETER ABLATION OF ATRIAL FIBRILLATION VIA A SINGLE TRANSSEPTAL ACCESS USING A BALLOON EXPANDABLE SHEATH AS AN ALTERNATIVE TO DOUBLE TRANSSEPTAL CATHETERIZATION

*N.G. Boyle, *D.A. Cesario, **J. Lenker, *M. Vaseghi, *K. Shivkumar, and #A. Natale *UCLA Cardiac Arrhythmia Center, Los Angeles, USA **Onset Medical Corporation, Irvine, USA #Cleveland Clinic Foundation, Cleveland, USA

Introduction: Catheter ablation of atrial fibrillation for pulmonary vein isolation requires double transseptal access. We report the first clinical use of a controlled balloon expandable transseptal sheath as an alternative to double transseptal access. The purpose of this study was to analyze and quantify the operator observed characteristics of a balloon expandable transseptal sheath in patients undergoing antral PVI.

Methods: We reviewed clinical data of six patients who underwent antral pulmonary vein isolation for paroxysmal atrial fibrillation (n = 6, 4 males, 2 females). Transseptal access was performed under intracardiac echocardiographic (ICE) guidance using a newly developed 18 Fr system (Solopath, Onset Medical Corporation) using a single pass technique. When the septum was crossed the sheath was expanded using an angioplasty balloon expansion system (Fig. 1, 16 atmospheres for 30 seconds).

Results: In all patients transseptal access was achieved without any difficulty. The balloon expansion was uneventful in all cases and there was stable anchoring of the sheath on the septum. All four pulmonary veins were accessed in 5/6 patients and in the remaining patient all the pulmonary veins except the right inferior was successfully cannulated. Multipolar PV mapping catheters and ablation catheters were used without any restriction in all cases (Fig. 2). There was no evidence of thrombus formation in any of the cases under ICE. Post ablation there was trace interatrial shunt detected by Doppler in 2/6 cases (33%).

Conclusions: This feasibility study demonstrates that a single transseptal access using a balloon expandable transseptal sheath can be performed safely and provides stable interatrial septal positioning for multiple catheter access.

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19. CRT: LV REVERSE REMODELING AND IDENTIFICATION OF NON-RESPONDERS

19.1 MYOCARDIAL PERFORMANCE INDEX AND LEFT VENTRICULAR DYSSYNCHRONY

*F. Cabrera-Bueno, *J. Peña-Hernandez, *J.M. Garcia-Pinilla, *M. Jimenez-Navarro, *A. Barrera-Cordero, *J. Alzueta-Rodriguez, *E. De Teresa *Cardiology Department, Hospital Universitario Virgen de la Victoria, Málaga, Spain

Introduction: This study was undertaken to analyze what proportion of patients (P) that qualify for cardiac resynchronization therapy (CRT) do not present echocardiographic criteria of dyssynchrony, as well as to analyze the response after CRT.

Methods: We prospectively studied patients with heart failure (HF) who met CRT criteria and who were sent for echocardiographic evaluation to define which parameters are related to the presence of intraventricular, interventricular and atrioventricular dyssynchrony. Echocardiographic response after CRT was also analyzed.

Results: Forty-five patients were included (62 ± 11 y). Thirty-one pts (68.9%) showed intraventricular, 29 (64.4%) interventricular and 11 (24.4%) atrioventricular dyssynchrony. P with intraventricular and interventricular dyssynchrony had a worse Myocardial Performance Index (MPI) (p < 0.001 and p = 0.003). No differences were found in the remaining clinical and echocardiographic parameters analyzed. CRT was performed in 30 patients. Significant improvement of the MPI (p = 0.037), end-systolic left ventricular volume (ESV) (p = 0.021) and EF (= 0.050) was observed.

Conclusions: More than 30% of P who met criteria for CRT according to the guidelines do not present echocardiographic dyssynchrony. The echocardiographic dyssynchrony identifies patients with worse MPI. CRT is associated to improvement of MPI, ESV and EF.

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Figure. 

19.2 LONG-TERM LEFT VENTRICULAR REMODELLING IN HEART FAILURE PATIENTS TREATED WITH CARDIAC RESYNCHRONIZATION THERAPY

*M. Cinello, *L.P. Badano, *M. De Biasio, *I. Armellini, *R. Marinigh, *N. Pezzutto, *D. Pavoni, *P. Gianfagna, *A. Proclemer, *D. Facchin, *M.C. Albanese, *P.M. Fioretti *Dipartimento di Scienze Cardiopolmonari, Istituto di Cardiologia, Azienda Ospedaliero-Universitaria di Udine, Udine, Italy

Introduction: Left ventricular (LV) reverse remodeling is an objective structural endpoint that heralds improved long-term survival. At the moment, limited data exist on the long-term impact of cardiac resynchronization therapy (CRT) on LV performance and remodeling. To address this issue, we examined echo data from our patients (pts) who underwent CRT and survived at least 4 years after implantation.

image

Figure. 

Methods: Pts (n = 141) with chronic HF (age 69 ± 11 years, 79% males, ischemic HF 51%, baseline EF 26 ± 8%, LBBB 74%, QRS width 177 ± 31 ms, NYHA class III-IV 61%) underwent CRT between July 1999 and November 2006. Clinical characteristics and echocardiographic findings (EDV, ESV, EF) on pre- and post-implantation examinations were collected by echo-lab database.

Results: During a mean follow-up of 29 months/pt, 38 pts (27%) died and 3 (2%) underwent heart transplantation. Echo-data obtained in 22 pts who survived at least 4 years are summarized in the figure.

Conclusions: CRT significantly improved LV function and reversed LV remodeling during long-term follow-up. Significant LV volume reduction occurs immediately after CRT; LV volumes then continue to decrease during follow-up until 4 years.

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19.3 FUNCTIONAL MITRAL REGURGITATION AND REVERSE REMODELLING IN CARDIAC RESYNCHRONIZATION THERAPY

*F. Cabrera-Bueno, *J.M. García-Pinilla, *J. Peña-Hernández, *M. Jiménez-Navarro, *J.J. Gómez-Doblas, *A. Barrera-Cordero, *J. Alzueta-Rodríguez, *E. De Teresa-Galván *Hospital Universitario Virgen de la Victoria, Málaga, Spain

Introduction: We undertook this study to determine whether the presence of functional mitral regurgitation (FMR) influences the reverse remodelling induced by CRT.

Methods: We used echocardiography to assess 20 patients with dilated cardiomyopathy before undergoing CRT and six months after. We evaluated the effects of reverse remodelling according to the presence or absence of important FMR, defined as a regurgitant orifice area of (ROA) ≥0.20 cm2.

Results and Conclusions: Of the 20 patients (64.7 ± 8.2 years), 9 had marked FMR (ROA 0.40 ± 0.12 cm2), 6 mild FMR (ROA 0.15 ± 0.02 cm2) and 5 had no FMR. CRT reduced the presence of FMR by 33.3% and induced reverse remodelling in 60% of the patients. A ROA ≥ 0.20 cm2 was associated with a lack of reverse remodelling, despite presenting similar reduction in asynchrony to the other patients. Reverse remodelling was produced in all the other patients, with a significant reduction in end-systolic volume (41.7 ± 21%;p = 0.003), accompanied by improvement in the ejection fraction (p = 0.003) and myocardial performance index (p = 0.027). CRT improved FMR, although the baseline presence of FMR, with a ROA≥0.20 cm2, in patients undergoing CRT was associated with a lack of response in reverse remodelling.

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19.4 VENTRICULAR ELECTRICAL DELAY VARIATION AS INDEX OF REMODELLING IN HEART FAILURE PATIENTS TREATED WITH CARDIAC RESYNCHRONIZATION THERAPY

*C.D. Dicandia, **L. Santangelo, ***C. La Rosa, *E. Pellegrino, ***S. Vitanza, **E. Ammendola, **I. De Crescenzo, ****I. Di Pumpo, ****C. Ciardiello *Casa di Cura Città di Lecce (GVM), Lecce ; **Seconda Università di Napoli, Naples ; ***Casa di Cura Villa Verde, Taranto ; ****Boston-Guidant; Italy

Introduction: The objective of this study is to assess in CRT patients the correlation between inter-ventricular delay changes and ventricular remodelling over a one year follow-up.

Methods and Results: Seventy-nine patients (male: 68%; age: 67 ± 10 years; NYHA class III: 84%; LVEF: 24.6 ± 5.9; dilated cardiomyopathy aetiology: idiopathic (IDIO) 50%, ischemic (CAD) 47%, other 3%; QRS duration: 161 ± 29 ms) were implanted with CRT defibrillators with distinct sensing channels (Guidant Contak Renewal IV®). During implant procedure the electrical delay in ms between right and left ventricle (VVD) was measured. At 12 month follow-up 30% of patients had a VVD which differed more than 15% in absolute value with respect to baseline. None of the 13% of patients with increased VDD – both clinical condition (NYHA class, HF hospitalizations) and LVEF – improved significantly. Conversely, all of the 17% of patients with decreased VDD showed a QRS shortening of at least 25%, a left ventricular systolic volume reduction superior to 30% and an ejection fraction improvement superior to 30% from baseline.

Conclusions: VVD shortening one year after CRT implantation is correlated with left ventricular remodelling in HF patients.

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19.5 NT PRO BNP TEST CAN BE USED TO ASSESS DEVICE THERAPY EFFICACY AND TO IDENTIFY PATIENTS FOR UPGRADING TO CRT

**C. Felicani, †E. Moccia, **F. Naccarella, ††F. Iachetti, *D. Vasapollo, ***M. Jasonni, †††A. H. Wang, ††††L. Sun, **G. Lepera *Medicina Legale, Università di Bologna, Bologna ; **Cardiologia Azienda USL, Bologna ; ***Cattedra di Diritto, Università di Modena, Modena ; †Medicina Legale Università di Roma, Rome ; ††Telbios Italia ; ††††Università di Perugia, Perugia, Italy †††Università di Pechino, Peking, China

Introduction: ProBNP is currently applied in the management and risk stratification of patients with CHF, and has recently been used to evaluate the efficacy of device therapy, mainly VVI versus CRT (DT).

Methods: Within the SHAPE project, three groups of CHF patients were evaluated in our out-patient CHF clinic: Group A) 7 consecutive non-selected patients on VVI pacing; Group B) 6 patients with CHF and CRT, and Group C) 3 patients on VVI or CRT therapies, in control condition and after 3 months of each treatment.

Results: In Group A, the mean value of proBNP was 2016 ± 751 pg/ml. We observed 3 episodes of major HF and 2 recurrences of minor CHF. In Group B, the mean value was 633 ± 389 pg/ml. In this group, no recurrences of major or minor HF episodes were observed. In Group C, an marked decrease in proBNP values was observed in the three months of CRT therapy, and a definite increase in proBNP values during VVI pacing. In this period, a concomitant deterioration of clinical status and echo-contractility and EF was observed Conclusions: Blood peptide values are an important tool for upgrading VVI pacing to CRT pacing in CHF patients, when the clinical evaluation of these patients is not completely adequate. Moreover, in CHF patients, the benefits of CRT versus VVI pacing can be assessed by serial proBNP evaluations.

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19.6 ATRIO-BIVENTRICULAR PACING IS BETTER THAN CONVENTIONAL STIMULATION FOR PATIENTS WITH HEART FAILURE AND BRADIARRHYTHMIA

*M. Martinelli, **O.T. Greco, *S.F. Siqueira, *R. Costa, COMBAT Study Group *Heart Institute (InCor) HCFMUSP, Sao Paulo, Brazil **Hospital de Base, Sao Jose do Rio Preto, Brazil

Introduction: COMBAT objective was to compare atrio-biventricular (ABivP) versus atrio-ventricular conventional pacing (AVCP) in patients (pts) with heart failure (HF) and pacemaker (PM) indication for bradi-arrhythmia.

Methods: After ABivP implant, 60 pts were randomized into: Group A –AVCP; B – ABivP. All pts underwent AV delay optimization (echocardiogram). At the end of 3, 6 and 9 month periods pts were crossed over and evaluated according to NYHA, Holter, echocardiogram, 6 min walking test (WT), QoL and peak oxygen consumption. Statistical analyses: Q-square test, variance analysis for repeated measures, Kaplan-Meier survival curve, Log-rank test.

Results: QoL showed significant improvement related to Group B (initial and final evaluation); worsening after crossover (opposite happened in Group A); NYHA presented significant improvement in Group B regardless crossover; WT was significantly better in Group B at final evaluation; peak oxygen and LVEF changes were not significant; while mitral regurgitation, LVESV and LVEDD presented significant reduction under ABivP; the death rate was 25% higher in group A (p = 0.0117).

Conclusions: In pts with HF and PM indication ABivP was superior, promoted better QoL, NYHA and echocardiogram parameters as well as reduced death rate.

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19.7 PHASE ANALYSIS OF BIVENTRICULAR AND INTRAVENTRICULAR ASYNERGY BY VELOCITY VECTOR IMAGING CAN DETECT NON-RESPONDERS PATIENTS TO CARDIAC RESYNCHRONIZATION

*A.R. Martiniello, *P. Caso, ***G. Pedrizzetti, **G. Tonti, *C. Cioppa, *S. Severino, *M.V. Betancourt, *E. Attena, *E. De Luca, *A. D'Onofrio, *S. Padula, *A. Giannolo, *R. Calabro *Monaldi Hospital, Naples, Italy **S.S. Annunziata Hospital, Sulmona, Italy ***Department of Civil Engineering, University of Trieste, Trieste, Italy

Introduction: Axius Velocity Vector Imaging-Siemens (VVI) is a novel image analysis approach that tracks the endocardial border after one initial trace and automatically determines radial (RD) and longitudinal displacement (LD). Phase (Ph) is a numerically more stable way of comparing the delay of one waveform relative to another, and incorporates information from the entire cardiac cycle.

Objective: We tested the hypothesis that VVI can analyse biventricular (BIV asy Ph) and intr-ventricular asynergy of the LV (LV asy Ph) to predict pts with CHF-LBBB and normal coronary arteries (NO ISCH) who do not respond to CRT (ESV < 15%) at 3-month follow-up examination.

Methods: Thirty-one pts (QRS duration: 155 ± 31 ms, 58 ± 11 yrs, 20 male) implanted with a CRT device and 18 controls were studied. BIV asy Ph and LV asy Ph were studied by using one initial trace of the tissue/cavity border from the RV free wall to the LV free wall, including the inter-ventricular septum, and from the left septum to the lateral wall, respectively. Asy Ph – LD and asy Ph – RD, expressed as the variability of difference (VAD%) and maximum difference (MD%), were estimated on an off-line VVI workstation, by 4ch view, using the two-basal, mid, and two-apical segment model.

image

Figure Figure. Figure 1 shows dot diagram and graph by VVI analysis (responder: 0; no responder: 1)

Download figure to PowerPoint

Results: VAD-LV asy-Ph RD (13.16 ± 4.9% vs 6.7 ± 3.9%, p 0.0001) and MD-BIV asy Ph-LD (13.2 ± 10.3% vs 6.9 ± 4.7%, p < 0.05) significantly increased in NO ISCH pts compared with controls. VAD-LV asy-Ph RD (9/14 pts, Sens. 78.6%, Spec. 70.6%), using cut off <=14% and MD-BIV asy Ph-LD (9/14 pts, Sens. 78.6%, Spec. 70.6%), using cut off <=11%, showed a better sensitivity and specificity in predicting the non-responder rate during follow-up. Figure 1 shows a dot diagram of data from VVI analysis (responder: 0; non-responder: 1).

Conclusions: Velocity Vector Imaging opens the door to new types of analysis of radial and longitudinal asynergy, which would help to identify CRT non-responders.

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19.8 STANDARD DEVIATION OF BIVENTRICULAR STRAIN RATE EJECTION CAN DETECT NON-RESPONDERS PATIENTS TO CARDIAC RESYNCHRONIZATION: CONTRIBUTION OF A NEW AUTOMATED ENDOCARDIAL TRACKING SYSTEM VELOCITY-VECTOR-IMAGING

*A.R. Martiniello, *P. Caso, **G. Tonti, ***G. Pedrizzetti, *E. De Luca, *C. Coppa, *I. Caso, *E. Attena, *M.V. Betancourt, *A. Lamberti, *A. Giannolo, *C. Cavallaio, *R. Calabro *Monaldi Hospital, Naples, Italy **S.S. Annunziata Hospital, Sulmona, Italy ***Department of Civil Engineering, University of Trieste, Trieste, Italy

Introduction: Axius Velocity Vector Imaging- Siemens (VVI), is a new image analysis approach that tracks the endocardial border after an initial trace, and automatically determines volumes, ejection fraction, myocardial velocity, strain rate (Tsr) and strain. We tested the hypothesis that VVI can detect differences in regional wall delay between the right (RV) and left ventricular (LV) to predict LV reverse remodelling post CRT ([DOWNWARDS ARROW]ESV > 15%) at 12 months f.u in pts with CHF-LBBB and normal coronary arteries (NO ISCH).

Methods: Twenty-two pts (53 ± 12 ys, 15 m, QRS duration: 149 ± 29 ms) implanted with CRT device and 20 controls were studied. The standard deviation of biventricular Tsr (Tsr-SD-BIV-ejection) was measured on an off-line VVI workstation that tracks the tissue/cavity border motion by RV free wall to LV free wall with septum enclosed.

Results: Tsr-SD-BIV-ejection showed a significant increase in NO ISCH pts compared with controls (NO ISCH: 25.9 ± 20.5 ms; Controls: 6.2 ± 5.4 ms (p < 0.0001). At f.u., the degree of Tsr-SD-BIV-ejection pre CRT correlated significantly with [DOWNWARDS ARROW]ESV(r −0.56, p 0.003). The non responder rate, using cut off < = 18.9 ms, was 5/5 (Sens. 100%, Spec:76.5%, p 0.0001)) at 12 months f.u.

Conclusions: Velocity Vector Imaging paves the way to new types of analysis on CRT.

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20. CRT: CLINICAL OUTCOMES

20.1 DO “REAL LIFE” PATIENTS IMPLANTED WITH CRT-D MATCH WITH THE POPULATION CHARACTERISTICS OF CLINICAL TRIALS? DATA FROM THE ACTION-HF REGISTRY

*G.L. Botto, **M. Mantica, ***C. La Rosa, ****L. Santangelo, †M.G. Bongiorni, ††R. Verlato, †††G. Villani, ††††G. Molon, ‡E. Occhetta, ‡‡R. Massa, ‡‡‡M. Ceppi, ‡‡‡F. Maggi, ‡‡‡‡C.D. Dicandia *Ospedale S.Anna, Como , **Clinica S. Ambrogio, Milan ; ***C.d.C. Villa Verde, Taranto ; ****Seconda Università di Napoli, Naples ; †Osp Cisanello, Pisa ; ††Osp. Civile, Camposampiero Padova ; †††Osp. Civile, Piacenza ; ††††Osp. Don Calabria, Negrar Verona ; ‡Osp. Maggiore della Carità, Novara ; ‡‡Osp Molinette, Turin ; ‡‡‡Guidant-Boston Scientific, Milan ; ‡‡‡‡Casa di Cura Città di Lecce, Lecce; Italy

Introduction: Patients implanted with CRT-D device for primary prevention in current practice may show different clinical characteristics with respect to large trials population and may be exposed to a different risk.

Methods: Aim of the analysis is to see if, in patients indicated for CRT-D for primary prevention enrolled in the ACTION-HF registry, clinical characteristics match those from COMPANION study.

Results: Data from 404 patients enrolled in ACTION-HF are compared with the 595 COMPANION patients implanted with CRT-D. Clinical characteristics do not substantially differ as to: QRS (160 vs 160), LBBB (76 vs 73) and heart rate (70 vs 72). Conversely, patients from ACTION-HF are moderately older (70 vs 66) and represent a less compromised population with respect to COMPANION study (NYHA class>II.

Conclusions: Clinical characteristics of patients currently implanted with CRT-D are representative of a different population with respect to COMPANION trial. “Real life” registries are useful in clinical practice as the enrolled population often show different characteristics with respect to their reference trials. Follow up data will show if these patients are exposed to different risks.

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20.2 LONG-TERM SURVIVAL IN HEART FAILURE PATIENTS TREATED WITH CARDIAC RESYNCHRONIZATION THERAPY

*M. Cinello, *L.P. Badano, *M. De Biasio, *I. Armellini, *R. Marinigh, *N. Pezzutto, *D. Pavoni, *P. Gianfagna, *A. Proclemer, *D. Facchin, *M.C. Albanese, *P.M. Fioretti *Dipartimento di Scienze Cardiopolmonari, Istituto di Cardiologia, Azienda Ospedaliero-Universitaria, Udine, Italy

Introduction: CRT improves 6-month survival in HF patients with clinical and ECG criteria for LV dyssynchrony. No definite data exist on long-term outcome after CRT. We reviewed survival and mortality predictors in all consecutive pts who underwent CRT in our institution.

Methods: Chronic HF pts (n = 141, 69 ± 11 years, 79% males, 51% ischemic, baseline EF 26 ± 8%, LBBB 74%, QRS 177 ± 31 ms, 61% NYHA III-IV, 17% persistent atrial fibrillation) underwent CRT between 1999 and 2006. Date and cause of death were obtained from chart review and the regional health system database.

Results: During a mean follow-up of 29 months/pt, 38 (27%) died (95% cardiac death) and 3 (2%) underwent heart transplantation. Post-CRT mean survival was 59 months (95% CI 52–67 months). The figure shows time-to-death Kaplan-Meier analysis. Cox-regression analysis showed that QRS > 220 ms (p = 0.0009) and pre-implantation EF ≤ 20% (p = 0.0001) were independent predictors of all-cause mortality. Age, sex, NYHA class and HF aetiology were excluded from the model.

Conclusions: Survival at 1, 2, 3 and 4 years was 80%, 72%, 64% and 48%, respectively. QRS duration and very low pre-implantation EF were identified as independent predictors of death.

Abstract

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20.3 LONG-TERM MORTALITY OF HEART FAILURE PATIENTS WITH BIVENTRICULAR IMPLANT: PACEMAKER VERSUS ICD

*F. Solimene, **M. Accogli, ***E. Bertaglia, ****V. La Rocca, ****A. De Simone, *N. Marrazzo, *G. Shopova, ***P. Pascotto, ****A. Iuliano, †C. Ciardiello, ****G. Stabile *Clinica Montevergine, Mercogliano, Avellino ; **Az. Osp. Pia Fondazione Cardinale G. Panico, Tricase, Lecce ; ***Ospedale Civile, Mirano ; ****Casa di Cura San Michele, Maddaloni, Caserta ; †Boston-Guidant; Italy

Introduction: The objective of this study has been to compare total mortality between patients with biventricular defibrillator (CRT-D) and biventricular pacemaker (CRT-P), over a long-term follow-up (mean 40±16 months).

Methods and Results: From February 1999 to July 2004, 188 patients (143 male; mean age: 68±9 years, NYHA class III: 68%, left ventricle ejection fraction (LVEF): 26.6±7.3, 48% idiopathic dilated cardiomyopathy, 47% ischemic, 5% other) underwent CRT-P (62 Guidant TR/TR2 and 27 Medtronic InsyncI/III) or CRT-D (99 Guidant Contak CD or Renewal I/II) implant. Clinical characteristics of CRT-D and CRT-P population match quite well except for gender and aetiology (male: 55% vs 66%; ischemic: 56% vs 36% CRT-DvsCDR-P, respectively, p<0,01). Difference in mortality (38% for CRT-P and 25% for CRT-D) did not reach statistical significance at log rank test (p = 0.08), only accounting for a trend in increased mortality for CRT-P group after 3 years. Age, sex, aetiology, LVEF and gender did not affect mortality in a multivariate Cox model.

Conclusions: CRT-D is superior in reducing overall mortality, though not to a significant extent; a longer follow-up or a larger sample size appear to be necessary to confirm this result.

Abstract

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20.4 CARDIAC RESYNCHRONIZATION THERAPY IN PATIENTS WITH ATRIAL FIBRILLATION WITHOUT ATRIOVENTRICULAR NODE ABLATION

*J.M. Garcia-Pinilla, *F. Cabrera-Bueno, *J. Peña-Hernandez, *J. Fernandez-Pastor, *J.J. Gomez-Doblas, *A. Barrera, *J. Alzueta, *E. De Teresa *Cardiology Department, Hospital Universitario Virgen de la Victoria, Málaga, Spain

Introduction: The role of cardiac resynchronization therapy (CRT) in patients with atrial fibrillation (AF) treated with medication for heart rate control has been poorly evaluated. The aim of this study was to compare the effects of CRT on ventricular function and reverse remodelling in heart failure patients with sinus rhythm (SR) and permanent AF who do not undergo atrioventricular (AV) junction ablation.

Methods: We assessed left ventricle (LV) asynchrony and function at baseline and after a 6-month implantation of a biventricular pacemaker. Fifty-five patients were included: 15 were on AF and 40 were on SR.

Results and Conclusions: There were no differences in baseline QRS width, LV function, and echocardiographic asynchrony. Device programming, QRS width reduction, and ventricular asynchrony after biventricular pacing were similar. A significant improvement in end-systolic volume (ESV) and ejection fraction (EF) were observed in both groups. However, patients on SR showed higher reverse remodelling (ESV reduction 30.9 ± 24.6% versus 12.5 ± 18.6%; p = 0.024). Heart failure patients with permanent AF treated with CRT and no AV ablation showed improvements of LV function and reverse remodelling, but this improvement was lower than that observed in patients in SR.

Abstract

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20.5 CARDIAC RESYNCHRONIZATION THERAPY IN PATIENTS WITH ATRIAL FIBRILLATION WITHOUT AV-NODAL ABLATION COMPARED TO SINUS RHYTHM: LONG-TERM OUTCOME

*A. Dorszewski, *C. Berndt, *J. Heintze, *A. Schmidt, *H. Buschler, *S. Ottemoeller, *U. Scholz, *B. Lamp, *J. Vogt *Department of Cardiology, Herz-Und Diabeteszentrum Bad Oeynhausen, Bad Oeynhausen, Germany

Introduction: Cardiac resynchronization therapy (CRT) and optimized medical therapy are the treatment of choice for patients (pts.) with congestive heart failure (CHF), NYHA > II-III, EF < 35% and QRS width > 150 ms. There are only few data for pts. with CHF and atrial fibrillation (AF) receiving CRT. The aim of our study was to compare CRT-pts. with AF to pts. with sinus rhythm (SR) during a follow-up (FU) period of 2 years. AV-nodal ablation was not performed on AF-pts., but they received optimized rate-controlled medication to avoid intrinsic conduction.

Methods and Results: 621 pts. (SR: n = 545; AF: n = 76) received CRT following acute testing prior implant. FU was 37 ± 17.9 months. Epidemiological data at baseline showed no significant differences between pts. with SR vs. AF: age 64 ± 13 vs. 62 ± 12 years; female 137 vs. 19; dilated cardiomyopathy 54 vs. 43%; coronary artery disease 36 vs. 34%; EF 22 ± 8 vs. 24 ± 7%, QRS width 184 ± 31 vs. 185 ± 37 ms. NYHA, VO2 peak and 6-minute walk improved significantly in both groups without significant difference between them. Left ventricular endiastolic diameter (LVEDD) showed a significant decrease only in SR-pts. and only a tendency to decrease in AF-pts., but not significantly. No significant difference was observed for total mortality, severe cardiac events, i.e., death, transplant (SR 15.7 vs. AF 21%).

Conclusions: Long term outcome of CRT-pts. with AF on rate-controlled medication demonstrates similar improvement in functional tests and no significant difference in total mortality and severe cardiac events after 2 years FU. CRT-pts. with AF improve without AV-nodal ablation, which appears to be avoidable, and optimized rate-controlled medication, which is of high importance.

  1. *p < 0.05, ° non-significant: SR vs. AF.

baseline
2-year FU
AF
SR
AF
SR
n
76
545
34
378
NYHA
3.2 ± 0.6
3.0 ± 0.3*
2.2 ± 0.9
2.1 ± 0.4°
VO2peak [ml/kg KG/min.]
12.1 ± 2.3
13.2 ± 3.1°
13.9 ± 5.1
15.5 ± 3.8°
6 min. walk [m]
339 ± 128
325 ± 116°
419 ± 97
434 ± 93°
LVEDD [mm]
77 ± 8
78 ± 11°
74 ± 8
70 ± 12*

Abstract

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20.6 USE OF FLUID ACCUMULATION MONITORING IN HF PATIENTS

*R. Alemanni, *A. Talerico, *G. Fabiano, *G. De Masi, *S. Canonico, *S. Iacopino *Medtronic Italia, Sesto San Giovanni, Milan, Italy

Introduction: Intra-thoracic impedance measurement has been introduced in the InSync Sentry and Concerto biventricular defibrillator and may permit early identification of pulmonary fluid accumulation secondary to left-sided heart failure (HF). An audible alarm (the OptiVol alert) is triggered when the impedance index increases to greater than a predefined level of 60 Ω· day. The aim of this study was to evaluate the clinical value of the OptiVol alert and its prediction for decompensation HF.

Methods: One hundred and six consecutive patients (mean NYHA class 2.6 ± 0.6, mean LVEF 24 ± 6%) who received biventricular defibrillators were included. When the OptiVol alert was triggered, current hemodynamic status was evaluated.

Results: During follow-up (mean 15 ± 5 months), there were 32 OptiVol alert occurrences in 21 patients. Clinical signs and symptoms of HF were present in 13 patients (41%), whereas in the remaining patients clinical signs of HF were absent (p < 0.05).

Conclusions: Intra-thoracic impedance measurement as featured in the InSync Sentry or Concerto biventricular defibrillator may be a useful tool for monitoring pulmonary fluid status.

Abstract

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21. ABLATION OF VENTRICULAR ARRHYTHMIAS

21.1 INTRAOPERATIVE ABLATION OF VENTRICULAR TACHYCARDIA GUIDED BY ELECTROPHYSIOLOGICAL STUDY AND ELECTROANATOMICAL MAPPING IN PATIENTS WITH CONGENITAL HEART DISEASE REQUIRING CARDIAC SURGERY

*M.C. Tavera, *S. Foresti, *P.P. Lupo, *M. Pittalis, *G. De Ambroggi, *H. Ali, *A. Giamberti, *M. Chessa, *D. Negra, *R. Cappato *Center of Clinical Arrhythmia and Electrophysiology, Cardiac Surgery Department and Paediatric Cardiology Department, GUCH Unit, Policlinico San Donato IRCCS, San Donato Milanese, Milan, Italy

Introduction: Arrhythmias are common in adult congenital heart disease (CHD) patients. Patients with pulmonary regurgitation (PR) and right ventricular dilatation after correction of RVOT obstruction may experience sudden death due to ventricular tachyarrhythmias.

Methods: Adult patients with PR and RV dilatation requiring cardiac surgery were examined. Baseline EPS was performed. When VT was induced, an electroanatomical map (EM) of the RV was acquired and, during surgery, RF ablation was performed at sites identified by previous mapping. In all patients, EPS was repeated 6 months after surgery.

Results: We analyzed 17 patients. In 3/17 patients, VT was reproducibly inducible (2/3 experiencing clinical VT). In these 3 patients, EM and ablation were performed. Six-months follow up data are available for 12/17 patients. None of them presented clinical VT. During a six-month FU, VT was induced only in 1/12 pts (not inducible at baseline). Control EPS was performed and was negative in 2/3 patients receiving ablation.

Conclusions: Intraoperative ablation guided by EM appears to be effective in patients with CHD presenting clinical or inducible VTs. Proarrhythmic role of surgery remains to be established.

Abstract

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21.2 LEFT VENTRICULAR DYSFUNCTION REVERSAL AFTER CATHETER ABLATION OF VENTRICULAR OUTFLOW TRACT PREMATURE VENTRICULAR COMPLEXES

*L. Sciarpa, *E. De Ruvo, **F. Lamberti, *A. Sette, *G. Navone, *F. Nuccio, ***P. Di Donna, *G. Carlino, *E. Lioy, ***F. Gaita, *L. Calo' *Policlinico Casilino, Rome, Italy **S.Eugenio Hospital, Rome, Italy ***Civil Hospital, Asti, Italy

Introduction: Repeated premature ventricular complexes (PVC) may determine left ventricular (LV) dysfunction. Some reports have suggested that the suppression of PVC with radiofrequency catheter ablation (RFA) may increase ventricular function in patients with dilated cardiomyopathy. The aim of this study was to evaluate the effect of RFA of PVC on LV function in patients with dilated cardiomiopathy.

Methods: The patient population included 22 patients with reduced left ventricular function (LV Ejection Fraction 37 ± 7), no evidence of underlying structural heart disease, and frequent PVC with ECG characteristic suggesting an origin from the right or left outflow tract. These patients were prospectively randomized to continue their usual care (control group: 10 patients, 6 female, 44 ± 6 years) or to attempt RFA of PVC (ablation group: 12 patients, 4 female, 47 ± 8 years). A 7 F, 4 mm electrode tip or a 3.5 irrigated tip, steerable catheter was used for mapping and ablation procedure. The left catheterization was performed with a transaortic retrograde approach. Local earliest ventricular activation during PVC and pace-mapping were used to identify the ablation site. A non-fluoroscopic mapping system was used in 7 patients.

Results: The clinical characteristics of the patients in the 2 groups were similar. At the baseline, the total number of PVC on 24 hours Holter monitoring was 25735 ± 12327 beats/day. The ablation was successful in 10 of the 12 patients of the ablation group (RF pulses 5 ± 3). The site of successful ablation was located in the left outflow tract in 2 patients, in the right outflow tract in 5 patients and close to the mitral annulus (posterior region). In 1 patient with frequent PVC of two morphologies the successful ablation sites were located in the right and in left outflow tract. There were no complications related to the procedure. After 8 ± 4 months of follow-up, RFA significantly reduced the number of total PVC (P < 0.01) and increased the LV ejection fraction (from 37 ± 7% to 47 ± 6%, P < 0.01). In the control group, there were no significant changes of the number of PVC and of ejection fraction.

Conclusions: In a subgroup of patients with idiopathic dilated cardiomyopathy and frequent PVC the RFA of PVC focus can improve LV dysfunction.

Abstract

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21.3 MAPPING AND ABLATION OF LATE POST-ISCHEMIC SUSTAINED VENTRICULAR TACHYCARDIAS, GUIDED BY VIRTUAL GEOMETRY AND 3D MAPPING SYSTEM

*S. Nardi, *C. Esposito, *M.M. Pirrami, *C. Marini, *G. Ranalli, *V. Borghetti, *A. Pardini, *G. Ambrosio, *G. Rasetti *Arrhythmia, Electrophysiologic Center and Cardiac Pacing Unit, Thoracic Surgery and Cardiovascular Department, Division of Cardiology, AO S. Maria, Terni, Italy

Introduction: The late recurrence of sustained ventricular tachy-arrhythmias (SVTs) after a previous myocardial infarction (MI) is generally related to slow conduction regions located at the infarct border zone. Conventional electrophysiologic criteria, often utilized for identifying the specific underlying operative mechanism, is challenging due to the high complexity of the arrhythmic circuits. Ensite System is an electro-anatomic mapping system able to create a three-dimensional (3D) model of cardiac endocardium, both for mapping and ablative purposes.

Methods: Twenty-seven patients with a previous MI who developed late post-ischemic SVTs, refractory to two or more different anti-arrhythmic drugs (AADs), underwent a NavX guided ablation procedure.

Results: The operative mechanisms were identified in 24/27 patients, with an acute success of the ablation's procedure in 23/27 patients. In 4/27 patients, we paced to treat an arrhythmic substrate due to multiple ongoing wave-fronts or variation of VTs cycle length. After 6 ± 12 months FU, 21/23 patients on previously ineffective AADs were free of VTs.

Conclusions: In these complex arrhythmias, NavX technology provided a realistic 3D geometrical reconstruction of LV chamber, with a precise identification of the operative mechanism of the arrhythmia.

Abstract

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21.4 RADIOFREQUENCY CATHETER ABLATION OF ELECTRICAL STORM: A THERAPEUTIC CHOICE

*C. Bisceglia, *G. Pelargonio, *A. Dello Russo, *M. Casella, *M.L. Narducci, *G. Bencardino, *R. Biddau, *A. Sparagna, *M.T. Lucciola, *P. Santarelli, *P. Zecchi, *F. Bellocci *Catholic University of Sacred Heart, Department of Cardiovascular Medicine, Institute of Cardiology, Rome, Italy

Introduction: Radiofrequency catheter ablation (RCA) of electrical storm (ES) is considered a rescue therapy; we report our initial experience about post-ischemic recurrent ventricular tachycardia.

Methods: RCA was performed in eight males with post-ischemic dilated cardiomyopathy (mean age 72.9 ± 9.4 years; mean EF 30.8 ± 9.7%) and incessant, drug-refractory ventricular tachycardia (VT). Electroanatomical CARTO system guided left ventricular mapping in 7 cases, whereas non-contact system (ESI 3000, SJM) in 5 procedures; substrate analysis and activation map of each tolerated VT were obtained. Target ablation sites were identified by isolated diastolic electrograms and confirmed with concealed entrainment, or by pace-mapping during sinus rhythm; linear lesions across diastolic pathway aiming to conduction block or focal ablation at exit points were drawn.

Results: Pleomorphic TV was observed in 2 patients (25%); complete success was achieved in 5 cases (62.5%); 3 patients (37.5%) underwent more than one procedure (mean 1.5), almost for in-hospital failure, switching mapping system. Finally, termination of ES was obtained in all patients, without periprocedural complications.

Conclusions: RCA, integrating contact and non-contact mapping system, could be a realistic choice in the treatment of ES.

Abstract

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21.5 STATIN THERAPY ALONE REDUCES RISK OF ICD SHOCKS IN PATIENTS WITH AN IMPLANTABLE CARDIOVERTER DEFIBRILLATION UNDERGOING ABLATION FOR VENTRICULAR TACHYCARDIA

*T.J. Bunch, *P.A. Friedman, *B.J. Gersh, *S.J. Asirvatham, *P.A. Brady, *Y.M. Cha, *A. Jahangir, *S.C. Hammill, *K. Monahan, *T.M. Munger, *R.F. Rea, *W.K. Shen, *N. Tabatabaei, *D.L. Packer *Division of Cardiovascular Diseases, Department of Internal Medicine, Mayo Clinic, Rochester, USA

Introduction: Lipid-lowering therapy reduces mortality in patients with both ischaemic and non-ischaemic cardiomyopathies and recently has been shown to decrease ICD shocks. Radiofrequency ablation (RFA) of recurrent VT in patients with an ICD also reduces shocks following intervention. It is unclear if statin therapy after VT RFA will further impact on ICD shock rates.

Methods: All patients from 1993–2005 who underwent an RFA procedure for recurrent VT at the Mayo Clinic with an ICD were included. Patient records were extracted for medical and procedural details and all ICD interrogations were reviewed for VT recurrence and therapies.

Results: 63 patients (age 62 ± 15 years) were followed over 3.9±3.6 years. Comorbid diseases included: coronary artery disease 37(58%, 34 prior myocardial infarction), ARVD/C 6(10%), non-ischaemic dilated cardiomyopathy 7(11%), moderate-severe valve disease 14(22%), hypertension 34(54%), and hyperlipidaemia 35(56%). Ejection fraction was <0.35 in 34(56%). VT was induced in all patients (LV 55 (LVOT 1), RV 8 (RVOT 3) with multiple inducible VTs in 21(33%). VT was non-inducible after RFA in 39(62%) patients. Dismissal medications included: statins 19(30%), beta-blockers 40(66%), ACE/ARB 37(61%), diuretics 34(55%), and digoxin 23(37%). 5-year overall survival was 63%(95% CI 55–71). Age, diabetes, and renal insufficiency were associated with increased post ablation mortality, with no medication improving survival. 5-year survival free of ICD shocks was 31%(95% CI 24–38). Only statin therapy at discharge was associated with a decreased risk of ICD shocks [5(26%) versus 26(59%), p = 0.020]. 7 additional patients received statins during follow up, but not at discharge; of these, 5(71%) had shocks.

Conclusions: Statin use at discharge in patients with an ICD undergoing RFA for refractory VT significantly reduced recurrent ventricular arrhythmias and ICD shocks. Although the mechanism underlying the effects of statins on arrhythmic recurrence early after RFA requires further study, these data support aggressive therapy of the underlying substrate responsible for the VT.

Abstract

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Wednesday, October 10, 2007 22. VASOVAGAL SYNCOPE: PATHOGENETIC AND THERAPEUTIC ASPECTS

22.1 ABNORMAL VASOCONSTRICTOR RESPONSE DURING HEAD-UP TILT TEST IN PATIENTS WITH VASOVAGAL SYNCOPE

*A. Pevzner, *G. Kheymets, *E. Kuchinskaya, *O. Ptichkina, *A. Rogosa, *S. Golitsyn *Russian Cardiology Research Center, Institute of Clinical Cardiology, Moscow, Russia

Introduction: The aim of this study is to analyze vasoconstrictor response (measured by impedance plethysmography (W. Kubicek) and level of norepinephrine (NE) in blood samples) in patients (pts) with positive and negative results in the head-up tilt tests (HUT).

Methods: Thirty-six men (mean age 34 ± 3 years old) with syncope of unknown origin were included in the study. HUT with beat-to-beat monitoring ECG, blood pressure (BP), stroke volume, cardiac output and total peripheral resistance (TPR) were performed. Level of NE in blood samples, obtained through venous catheter, was assessed twice: in recumbent position and in 40 minutes of orthostasis (in pts with negative results of HUT) or in syncope (in pts with positive results). Twenty pts demonstrated vasovagal syncope during HUT (mean time 20 ± 2 min).

Results: Pts with syncope did not significantly differ from pts with negative HUT results on changes of stroke volume and cardiac output. Pts with syncope in comparison with pts with negative HUT results showed less expressed increase than mean BP and TPR. Level of NE significantly decreased in pts with syncope during orthostasis (77.2 μg/ml) in comparison with those in recumbent position (181.6 μg/ml), but it significantly increased in pts with negative HUT results (233.4 and 384.5 μg/ml, respectively).

 012345
  1. 0 – recumbent position; 1–5 – minutes of orthostasis.

TPR (HUT +), din*s*sm−5176819152053205920722077
TPR (HUT −), din*s*sm−5140521252201212321512033
Mean BP (HUT +), mmHg88.790.390.588.88990.5
Mean BP (HUT −), mmHg91.798.4102103.4101101

Conclusions: Pts with vasovagal syncope, unlike pts with negative HUT results, have a poor vasoconstrictor response. This fact could be taken into account when regarding pathogenesis of vasovagal syndrome.

Abstract

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22.2 SINUS NODE FUNCTION IN PATIENTS WITH CARDIOINHIBITORY VASO-VAGAL SYNCOPE

*A.Z. Pietrucha, *M. Wnuk, *E. Wojewodka-Żak, *M. Wegrzynowska, *D. Mroczek-Czernecka, *I. Bzukała, *E. Konduracka, *W. Piwowarska *Coronary Disease Department, Institute of Cardiology, Medical School of Jagiellonian University, John Paul II Hospital, Cracow, Poland

Introduction: The aim of this study is to evaluate the sinus node function in patients with cardio-inhibitory vaso-vagal syncope (CI VVS). To this purpose we studied 41 pts (20 female, 21 male) aged 18–52 yrs. Other syncope causes differing from CI VVS were excluded in all pts.

Methods: All pts underwent transoesophageal atrial stimulation (AS) for evaluation of extrinsic and intrinsic sinus node recovery times (SNRT) and corrected sinus node recovery times (CNRT), sino-atrial conduction time (SACT) and Wenckenbach point (WP). Pharmacological blockade (PHB) of sinus node was achieved with iv propanolol and atropine administration. SNRT > 1500 ms and CNRT > 525 ms were regarded as abnormal. All pts also underwent carotid sinus massage. A > 3 secs ventricular pause was regarded as positive response.

Results: Mild prolongation of extrinsic SNRT and/or CNRT with normalization after pharmacological blockade (functional SND) was observed in 8 pts (19.5%). Mild organic sinus node dysfunction (with max CNRT 760 ms) was detected in 1 pt (2.4%). The remaining patients showed normal SNRT values. Decreased intrinsic heart rate was observed in 7 pts (17.1%). Mild to moderate decrease of WP was observed in 7 pts (17.1%). Carotid sinus hypersensitivity was observed in 4 pts (9.8%).

Conclusions: Mild sinus node dysfunction as well as carotid sinus hypersensitivity were observed in about 10–20% of patients with cardio-inhibitory vaso-vagal syncope; these factors do not seem to account for pathogenesis in this class of vaso-vagal reaction.

Abstract

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22.3 ASYSTOLE INDUCED BY PARTIAL SEIZURES: A RARE CAUSE OF SYNCOPE

*V. Carinci, *G. Barbato, *F. Pergolini, *G. Di Pasquale *Cardiology Unit, Maggiore Hospital, Bologna, Italy

Introduction: A 78-year-old man was admitted due to a traumatic syncope. Twenty years earlier he had undergone pituitary adenoma operation. After the syncope he reported severe asthenia with nausea and vomit. The initial diagnosis was vasovagal syncope.

Methods: The following day he presented a spontaneous seizure and an EEG was immediately performed. During the EEG the patient had an ictal episode and a contemporary severe bradyarrhythmia occurred, with asystolia lasting 10 sec. After this episode a DDD pacemaker was implanted.

Results and Conclusions: The clinical distinction between cardiovascular and epileptic causes of loss of consciousness is sometimes challenging. Epilepsy may be correlated to severe bradycardia or asystole. The syndrome is called ictal bradycardia syndrome. Ictal bradycardia and asystole have been implicated in the aetiology of sudden unexpected death in epileptic patients (SUDEP), one of the leading cause of death in epilepsy. Investigation for life-threatening arrhythmic events in high-risk epileptic patients is perhaps to be recommended. Some data suggest utilization of implantable loop recorder. In the case of ictal bradycardia syndrome, pacemaker implantation is warranted.

Abstract

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22.4 EFFICACY OF MEDICAL COMPRESSION STOCKINGS IN PATIENTS WITH RECURRENT VASOVAGAL SYNCOPE

*E.A. Kuchinskaya, *A.V. Pevsner, *E.V. Vershuta, *K.V. Albitskaya, *E.A. Egorova, *G.I. Heimets, *A.N. Rogosa, *S.F. Sokolov, *S.P. Golitsyn *Department of Clinical Electrophysiology, Institute of Clinical Cardiology, Russian Cardiology Research Center, Moscow, Russia

Introduction and Methods: Nine patients (pts) with vasovagal syncope (VVS) were included in the study. Maximal load exercise stress tests (MET) were used for control of efficacy of medical compression stockings (MCS) (Sigvaris, Ganzoni & Cie AG, 25–30 mm Hg). MET consists of maximal load with sudden stop and rest period in active ortostasis until syncope or for 20 minutes. Design included two control MET for each pt (to assess the reproducibility of syncope) and one MET while wearing in MCS.

Results: Before treatment all nine pts had vasovagal syncope during both control MET. None of the nine pts had syncope during MET while wearing MGS. The effects of the MCS were estimated clinically during a follow-up of up to 24 months. MCS was effective in preventing syncope in five pts (56%), whereas four pts (44%) stopped using MCS because of low compliance.

Conclusions: MCS is a valuable treatment for patients with vasovagal syncope both during acute test and during follow-up. The patient compliance, however, is low during chronic treatment.

  HR bpmSNRT msWP ppmAVRP msHRV >6 m msp
CNAPre58 ± 121953 ± 1124140 ± 34421 ± 124164 ± 49<0.0002
N = 65Post74 ± 121082 ± 215167 ± 41311 ± 88 94 ± 41 
ControlPre79 ± 221351 ± 208169 ± 55319 ± 121142 ± 49>0.08
N = 51Post75 ± 111228 ± 262155 ± 33311 ± 137134 ± 38 

22.5 CARDIONEUROABLATION IMPACT ON THE ELECTROPHYSIOLOGICAL CHOLINERGIC PARAMETERS: A COMPARATIVE STUDY

*E.I. Pachon, *T.J. Lobo, *J.C. Pachon, *M.Z.C. Pachon, *R.N.A. Vargas, *L.S. Piegas, *A.D. Jatene *Heart Hospital – HCor and Dante Pazzanese Cardiology Institute – São Paulo, Brazil

Introduction: Cardioneuroablation (CNA) is a novel option for treating functional bradyarrhythmias (neurocardiogenic syncope and sinus/AV node dysfunction – FB) by catheter ablation of the neurocardiac interface without pacemaker implantation. The innervation entry causes slight endocardial conduction changes that may be detected by spectral mapping (SM). The RF ablation of these points could be used to treat the FB. The aim is to evaluate the CNA acute effect over the cholinergic parameters (ChP): HR, SNRT, WP, AVRP and HRV compared to a control group.

Methods: CNA: 65p having FB, 41 ± 14 y (palpitations 33, dizziness 28 or syncope 17) underwent an electrophysiological study + CNA guided by SM without neural stimulation. All spectral shifted points were ablated [4–8 mm/30 J/60 °C/30 s] in both atria using transeptal puncture. Control: 51 pts, 47.5 ± 18 yrs, were submitted to electrophysiological study + RF ablation of tachycardias in right and left atria.

Results: Pre and Post RF comparison of CNA x Control:

Conclusions: The SM was able to guide the CNA being a good marker of the neurocardiac interface. The significant changes in the cholinergic parameters after CNA and this absence in the control group suggested that the CNA causes an important vagal disinnervation lasting more than 6 months, probably through the elimination of the visceral neurone (□HRV >6 m). These effects may explain why the CNA is having good results in the FB treatment.

Abstract

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22.6 ROLE OF SYNCOPE MANAGEMENT UNITS

*W.K. Shen, **M. Brignole *Department of Cardiovascular Diseases, Mayo Clinic, Rochester, USA **Department of Cardiology and Arrhythmologic Center, Ospedali Riuniti, Lavagna, Italy

Introduction: A critical pathway to evaluate and manage patients with syncope in hospitals and emergency department (ED) is under investigation.

Methods: A systematic review of recent prospective studies on syncope management units.

Results: EGSYS, OESIL, and ECSIT assessed the utility of a syncope unit in general hospitals in Italy. These studies showed a high degree of variability in practice patterns, diagnostic yields, length of hospital stay and accumulated expenditures. The EGSYS-II study reported a standardized-care pathway, following the ESC guidelines, significantly improved syncope evaluation outcomes. The SEEDS study, from a tertiary hospital in US, demonstrated that a designated ED unit improved diagnostic yield and reduced hospital admission and total length of hospital stay in intermediate risk patients randomized to the syncope unit evaluation as compared to the patients randomized to the conventional evaluation. During follow-up, survival and recurrence of syncope were similar between the two groups.

Conclusions: Limited data suggest a designated syncope unit holds the promise of providing specialized and efficient care for patients with syncope. Additional data are needed to assess the general applicability of this critical pathway in community-based hospitals.

Abstract

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22.7 EXERCISE-INDUCED CHRONOTROPIC RESPONSE OF SINUS NODE IN PATIENTS WITH CARDIOINHIBITORY VASO-VAGAL SYNCOPE

*M. Wnuk, *A.Z. Pietrucha, *E. Wojewodka-Żak, *M. Wegrzynowska, *D. Mroczek-Czernecka, *I. Bzukała, *E. Konduracka, *W. Piwowarska *Coronary Disease Department, Institute of Cardiology, Medical School of Jagiellonian University, John Paul II Hospital, Cracow, Poland

Introduction: The aim of study was to evaluate exercise induced chronotropic response of sinus node in patients with cardioinhibitory vaso-vagal syncope (CI VVS). To this purpose 41 patients – 20 female, 21 male, aged 18–52 yrs – were studied. Other causes of syncope differing from CI VVS were excluded in all pts.

Methods: All pts underwent treadmill exercise test (ETT) in compliance with modified Bruce protocol. Duration of exercise, achieved heart rate (HR) peak expressed as percentage of maximal age-predicted HR (calculated from 220-age formula) and maximal metabolic workload (METS) were calculated. Chronotropic incompetence was defined as failure to reach 85% of maximal age-predicted HR.

Results: Stress test was well tolerated by all pts. Mean duration of ETT was 10.9 min (5.2–18.35 min.). Mean reached metabolic workload was 10.1 METS (4.4–19). During exercise 60–103% of age-predicted maximal HR was achieved (mean – 85.5%). Chronotropic incompetence was diagnosed in 9 pts (21.9%), who reached 60–76% of maximal age-predicted HR (mean value 70.2%).

Conclusions: Chronotropic incompetence was observed in about 20% of patients with cardioinhibitory vaso-vagal syncope and might account for pathogenesis in this class of vaso-vagal reaction.

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23. UNEXPLAINED SYNCOPE/PALPITATIONS/CAROTID SINUS SYNDROME/AUTONOMIC FAILURE

23.1 PREVALENCE OF J WAVES IN 12-LEAD ELECTROCARDIOGRAM IN PATIENTS WITH SYNCOPE AND NO ORGANIC DISORDER

*A. Abe, *H Yoshino, *H. Ishiguro, *T. Tsukada, *Y. Miwa, *K. Sakaki, *M. Miyakoshi, *H. Mera, *K. Nakamura, *S. Yusu, *T. Ikeda *Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan

Introduction: It has been reported that J waves in 12-lead electrocardiogram (ECG) are associated with the occurrence of serious arrhythmias. We assessed the prevalence of J waves in patients with syncope and no organic disorder, and compared it to that of a large sample of healthy control subjects.

Methods: This study enrolled 222 consecutive syncope patients (46 ± 18 years and 142 men) and 3,915 control subjects matched by age and gender. The presence of J waves was determined using a computerized 12-lead ECG system. The J wave was defined as >0.5 mm (definition-A) or >1.0 mm elevation (definition-B) at the J point compared to baseline.

Results: Of the patients, the prevalence of J waves with definition-A was 41 patients (18.5%); 30 in the inferior leads and 21 in the left lateral leads, revealing an overlap. Their prevalence (81 subjects; 2.0%) was significantly greater than that of the control group (P < 0.0001). The same applied for definition-B.

Conclusions: J waves in 12-lead ECG were often observed in patients with syncope. Abnormalities in the terminal portion of QRS complex may be relevant to the etiology of syncope.

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23.2 ARE MAYER WAVE DYNAMICS ALTERED IN VASODEPRESSOR SYNCOPE?

*,**C. Finucane, **G. Boyle, **,***R. Kenny *Mercer's Institute for Research on Ageing, St. James's Hospital, Dublin, Ireland **Dept. Medical Physics and Bioengineering, St. James's Hospital, Dublin, Ireland ***Dept. Gerontological Medicine, Trinity College, Dublin, Ireland

Introduction: Mayer Waves are low frequency (circa 0.04–0.15 Hz) blood pressure waves found in humans, thought to originate from limit cycle dynamics that emerge due to the presence of a sigmoidal non-linearity in the baroreflex pressure/response characteristic. It seems reasonable to hypothesize that individuals with Vasodepressor Carotid Sinus Syndrome (VDCSS) may exhibit increased Mayer wave amplitude due to a hypersensitive baroreflex and furthermore may show a change in oscillation frequency. This hypothesis is tested here.

Methods: Elderly patients (n = 15; 7 male; age range 62–87) were recruited prospectively from a dedicated Fall's and Blackout Diagnostic Unit, 6 of whom were diagnosed with VDCSS following Carotid Sinus Massage (CSM). The remaining subjects had a normal CSM response. Ten minute ECG and continuous beat-to-beat blood pressure (TNO Finapres©) recordings were taken. Signals were sampled at 200 Hz, and filtered between 0.01–100 Hz and stored digitally. Subjects were instructed to lie supine, in a temperate (23°C), comfortably lit, low-noise environment, while measurements were taken. Following an initial 5-minute stabilization period Physiocal(c) was switched off and data were recorded for a further 5 minutes. Diastolic Blood pressure records were linearly detrended. Autocorrelation was performed to accentuate periodic limit cycles in the signal. Subsequently the power spectrum (Welch's Method) was found. Existence of a resonant peak in the 0.04–0.15 Hz band was confirmed visually. Its Centre of Frequency (COF) and amplitude of this peak, ACOF, were then extracted.

Results: A resonant peak existed in 6 from 6 VDCSS cases and 5 out of 9 normal cases. Grand average power spectra (Figure 1A) was significantly higher at 0.08 Hz and 0.16 Hz (p < 0.05) in VDCSS. COF and ACOF also increased with VDCSS.

Conclusions: Mayer waves with higher amplitudes and frequency were demonstrated in VDCSS, possibly arising from an increased baroreflex gain. This tends to support the notion that Mayer Waves result from limit cycle dynamics. Future work will investigate this approach further, as a basis for convenient diagnosis of VDCSS, with implications for syncope and falls management.

  • image(1)

[A) Power Spectrum (0.04 Hz–0.16 Hz)]

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23.3 CAROTID SINUS HYPERSENSITIVITY AND APOLIPOPROTEIN E3/4 ARE ASSOCIATED WITH COGNITIVE IMPAIRMENT IN THE ELDERLY

*S.J. Kerr, *V.M. Miller, *C.M. Morris, *J. Hampton, *R.A. Kenny *Institute for Ageing and Health, Wolfson Research Centre, Newcastle General Hospital, Newcastle upon Tyne, UK

Introduction: Carotid Sinus Hypersensitivity (CSH) is associated with cerebro-hypoperfusion and highly prevalent in dementia. The Apolipoprotein (Apo) E4 allele is a strong risk factor for dementia, and may be associated with CSH, yet role or frequency of Apo E4 in cognitive impairment in CSH is unknown.

Methods: We compared Mental State Exam (MMSE) and Cambridge Cognition (CAMCOG) scores with respect to Apo E allele status, between 179 (76.7 yrs 106 m 73 f) subjects with CSH and 70 (72.8 yrs 37 m 33f) subjects without CSH.

Results: Non parametric statistical analysis showed CSH subjects had lower MMSE (p = 0.000) and CAMCOG (p = 0.000) scores than control subjects. Apo E3/3 was frequent in 65% of CSH and 77% of control subjects, and Apo E3/4 in 14.5% of CSH and 8.5% of control subjects. The cognitive scores of Apo E3/4 CSH were lower than both Apo E3/3 CSH (MMSE; p = 0.000, CAMCOG; p = 0.000) and ApoE 3/4 control subjects (CAMCOG; p = 0.025).

Conclusions: CSH and ApoE3/4 are associated with decreased cognitive function. A longitudinal study may reveal the potential cumulative detrimental effects of episodic cerebro-hypoperfusion in CSH and ApoE 3/4 status in the elderly.

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23.4 ORTHOSTATIC HYPOTENSION AS A RECURRING CLINICAL MANIFESTATION OF PHEOCHROMOCYTOMA: A CASE REPORT

*M. Bortnik, *E. Occhetta, *F. Vassanelli, *P. Marino *Division of Cardiology, Università del Piemonte Orientale, Novara, Italy

Introduction: Pheochromocytoma is a rare endocrine tumour with highly variable external traits, related to increased catecholamine secretion; a severe orthostatic hypotension could be the first clinical manifestation of this challenging entity.

Methods and Results: A 74-year-old man with a history of hypertension was admitted to our department because of several episodes of syncope and pre-syncope. ECG showed sinus rhythm and right bundle branch block; blood pressure was 150/85 mmHg in the supine and 85/60 mmHg in the standing position. Transthoracic echocardiography displayed a mild left ventricular hypertrophy. A voluminous mass (90 mm in diameter) in left adrenal gland mass was revealed by computed tomography scans. Diagnosis of pheochromocytoma was ultimately confirmed by means of (123)I MIBG scintiscan and biochemical test samples for plasma catecholamine measurements. The surgical excision of the tumour resulted in clinical improvement with normalization of plasma catecholamine concentrations and no more episodes of orthostatic hypotension over a 24-month follow-up.

Conclusions: Pheochromocytoma may frequently cause orthostatic tolerance disorders and should be considered in case of unexplained new-onset orthostatic hypotension with frequent syncope or pre-syncope episodes.

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23.5 RESPIRATORY COUNTERMANOEUVRES IN AUTONOMIC FAILURE1

*R.D. Thijs, **W. Wieling, ***J.G. Van Den Aardweg, *J.G. Van Dijk *Department of Neurology and Clinical Neurophysiology, Leiden University Medical Centre, Leiden, the Netherlands **Department of Internal Medicine, Academic Medical Centre, Amsterdam, the Netherlands ***Department of Pulmonology, Medical Centre Alkmaar, Alkmaar, the Netherlands

Introduction: Selective increase of inspiratory impedance augments blood pressure (BP) in healthy subjects through the respiratory pump. We studied the efficacy of respiratory manoeuvres in reducing orthostatic hypotension in autonomic failure.1

Methods: Mean arterial pressure (MAP) after standing up was recorded in 10 patients in five conditions: normal standing, leg muscle tensing, inspiratory pursed lips breathing, inspiratory sniffing, and a device causing inspiratory obstruction.

Results: The manoeuvres caused significant differences in standing MAP. Inspiratory obstruction and leg muscle tensing increased MAP to a comparable degree. The effect of inspiratory pursed-lips breathing and inspiratory sniffing depended on concomitant hyperventilation.

Conclusions: Respiratory manoeuvres reduce orthostatic hypotension in autonomic failure through activation of the respiratory pump, provided hyperventilation is avoided.

1Neurology 2007 (in press)

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23.6 DIAGNOSING RECURRENT UNEXPLAINED PALPITATIONS: THE RUP STUDY

*M. Madalosso, *F. Giada, *I. Colangelo, *M. Gulizia, *M. Francese, *F. Croci, *M. Santomauro, *C. Menozzi, *A. Raviele *Cardiovascular Department, Umberto I Hospital, Venice-Mestre, Italy

Introduction: The aim of this multicenter, prospective, randomized study was to compare the cost-effectiveness ratio of implantable loop recorder (ILR) and conventional diagnostic strategy (CDS), in patients with palpitations that remain unexplained after the initial evaluation (history, physical examination, 12-lead ECG).

Methods: We studied 50 consecutive patients without severe structural heart disease (SHD) (ejection fraction >35%), and with infrequent (≤1 episode per month), sustained (>1 minute), and clinically significant (associated to pre-syncope, diaphoresis, chest pain, asthenia) palpitations. Patients were randomized either to CDS, including a 24-hour Holter monitoring, 4-week external ambulatory ECG recorders and an electrophysiological study (EPS) (n = 24) or to an ILR implantation (n = 26) with a 1-year monitoring. Full hospital costs of each investigation were calculated.

Results: The main results are reported in Table 1. The incremental cost-effectiveness ratio for ILR strategy was low (€ 1,576) in relation to the costs of further investigations and acute events management, which are necessary when the diagnoses are fewer. Sensitivity analysis showed that the mean cost per diagnosis remained significantly lower in ILR group, except for EPS 50%.

Table 1. 
 CDSILR implantationp
N° of patients2426 
N° of diagnosis, (%)5 (21)19 (73)<0.001
Mean cost/patient, €2,233 ± 2651,410 ± 1.389<0.001
Mean cost/diagnosis, €3,056 ± 3636,768 ± 6.6720.012

Conclusions: In subjects without severe SHD and with infrequent palpitations, ILR is a safe and more cost-effective diagnostic approach than CDS, and may be a useful primary strategy in the evaluation of these patients. EPS constituted the main cost driver in CDS and it is not cost-effective in patients without SHD.

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23.7 UTILITY OF AN EXTERNAL LOOP RECORDER IN DIAGNOSING PATIENTS WITH SPORADIC PALPITATIONS OR SYNCOPE

*L. Sciarra, *A. Sette, *E. De Ruvo, *F. Nuccio, *M. Topai, *G. Navone, *G. Carlino, *A.M. Martino, *E. Lioy, *L. Calò *Department of Cardiology, Policlinico Casilino, Rome, Italy

Introduction: Spider flash (SF) is an external digital ECG loop recorder. When symptoms occur, one presses the event button and all ECG data acquired between a programmable time before and after the event are stored. The aim of this study is to evaluate the utility of SF in the diagnosis of pts with sporadic episodes of paroxysmal palpitations (PP) and or syncope/pre-syncope.

Methods: Eighty-three pts (46 ± 19 y; 24 males) were studied. Sixty-four pts (44 ± 17 y; 18 males) with PP; six pts (36 ± 13 y; 1 male) with sporadic episodes of syncope associated with palpitations; thirteen pts (60 ± 25 y; 5 males) with sporadic episodes of syncope and/or presyncope.

Results: Duration of recording: 20 ± 7 days. In the group of pts with PP we recorded: in 11 pts (17%) episodes of paroxysmal supraventricular tachycardia (PSVT); in 26 pts (41%) sinus tachycardia; in 4 pts (6%) an episode of atrial fibrillation (AF) or atrial flutter; in 10 pts (16%) frequent ventricular premature beats; in 5 pts (8%) frequent atrial premature beats; in 2 pts (3%) a second degree atrioventricular block during sinus tachycardia. In the group of pts with PP + syncope and or pre-syncope we recorded: in 4 pts (67%) a PSVT. In the group of pts with syncope and or pre-syncope we recorded: in 3 pts (24%) sinus bradycardia; in one pt (8%) very fast atrial fibrillation in correspondence with the syncope.

Conclusions: SF was revealed to be a useful device in patients with sporadic episodes of paroxysmal palpitations and/or episodes of unexplained syncope and/or pre-syncope. The possibility of a loop memory (ECG signal continuously stored) permits the recording of the beginning of arrhythmic events that could not be detected by a common “event recorder”.

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23.8 CARDIAC PACING THERAPY IN PATIENTS WITH BIFASCICULAR BLOCK AND UNEXPLAINED SYNCOPE: A PRESS STUDY

*F. Giada, **A. Castro, **M.L. Loricchio, ***G. Giaggioli, ****S. Orazi, †M. Viscosi, ††A. Bartoletti, †††L. Calò, ††††G. Inama, ‡G. Marras, ‡‡R. Ricci, ‡‡M. Santini *A.O. Umberto I, Venice-Mestre; **Osp. S. Pertini, Rome; ***A.O. Villa Scassi, Genova; ****O. S.Camillo de’ Lellis, Rieti; †A.O. S. Sebastiano, Caserta; ††Osp. S Giovanni di Dio, Florence; †††Policlinico Casilino, Rome; ††††Osp Maggiore, Crema; ‡Boston Scientific, Milan; ‡‡AO S. Filippo Neri, Rome; Italy

Introduction: Patients with recurrent syncope undiagnosed after non-invasive and invasive testing pose a diagnostic and therapeutic dilemma. Purpose of the PRESS study is to evaluate the efficacy of pacing in patients with bifascicular block and unexplained syncope.

Methods: All patients have been implanted with a dual chamber pacemaker programmed in DDD mode with 60 bpm pacing rate or DDI mode with 30 bpm pacing rate. The primary endpoint is to demonstrate a 20% reduction in the syncopal and presyncopal episodes recurrence between the two groups. Inclusion criteria are bifascicular block, ≥ 1 syncope over the last six months, negative response to tilt testing and to electrophysiologic study, ejection fraction ≥ 40%.

Results: Among 43 patients baseline characteristics were similar between DDD and DDI groups (P = NS). Age: 79 ± 5 vs 78 ± 6; male gender: 55% vs 45%; BAV: 40% vs 35%; ejection fraction: 57 ± 9 vs 61 ± 10 NYHA>I: 68% vs 71%. There were 4 syncopal and 17 pre-syncopal episodes during follow up.

Conclusions: The PRESS study will assess pacing therapy efficacy in patients with bifascicular block and unexplained syncope. Its results are expected to produce advancements in outlining diagnostic and therapeutic strategies in this population.

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24. CARDIAC ARRHYTHMIAS: SURGICAL APPROACH

24.1 EARLY EXPERIENCE OF TRANS-CATHETER MAZE (TCM) PROCEDURE FOR PATIENTS WITH ATRIAL FIBRILLATION IN SOUTH AFRICA

*A. Saaiman, *S. Land *SA Endovascular, Netcare Kuilsrivier Hospital, Kuilsrivier, Western Cape, South Africa

Introduction: Following current guidelines, catheter ablation for atrial fibrillation (AF) is a rapidly growing therapeutic modality in South Africa. This study reports our early experience with pulmonary vein (PV) ablations.

Methods and Results: A 3D model of the left atrium (LA) was created using the NavX Ensite system. TCM procedure was performed in the LA (circumferential PV, roof and LA isthmus lines) as described by Pappone et al. Success of PV disconnection was confirmed using peak-to-peak voltage mapping. 33 patients were treated: 15 with permanent AF; 18 with paroxysmal AF. Mean age was 61 years (30–81; M: 24, F: 9). Mean procedure time was 227.6 minutes and mean fluoroscopy time 92.5 minutes.

All ComplicationsN
Phrenic nerve palsy1
Pericardial effusion3
 requiring pericardiocentesis

Sinus rhythm, at least three months post procedure, was considered a success. Success rate is 67% (permanent: 6, paroxysmal: 16).

Conclusions: TCM using 3D mapping technology is an effective treatment for AF and success rate should increase with experience. Cost effectiveness remains to be assessed in South Africa.

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24.2 REDUCTION OF ATRIAL FIBRILLATION AFTER MAZE SURGERY USING CRYOABLATION

*E. Rošková, **M. Hulman, ***P. Olexa, ***B. Stančák *Dept. of Cardiology, Košice, Slovakia **Cardiac Surgery and Arrhythmology, Košice, Slovakia ***Eastern Slovakian Institute of Cardiovascular Diseases, Košice, Slovakia

Introduction: To evaluate the efficacy of cryoablation for the MAZE procedure as a therapy for atrial fibrillation Methods: MAZE procedure was performed in 58 patients in the period 3/2004–6/2005 as a part of a cardiosurgical operation planned for other reasons (replacement/repair of mitral valve, replacement of aortic valve, repair of tricuspid valve, coronary artery by-pass grafting and others, or their combination). Patients were followed up at regular intervals after the procedure (soon after and at 3, 6, 12 and 18 months following the procedure).

Results: The type of pre-operative atrial fibrillation was paroxysmal in fourteen patients and permanent in all the others. Only 46 patients were followed up for more than 3 months after the operation. Sinus rhythm was present in 24 (63%) patients. After 6 months, 38 patients were evaluated, and sinus rhythm persisted in 29 (76%). One year after MAZE procedure, 18 patients were examined and sinus rhythm was observed in 13 patients (72%). At 8 months, 11 patients were followed up and sinus rhythm was found in 8 (73%). Duration of atrial fibrillation preoperatively, LV ejection fraction and the age of patients did not have any influence on the persistence of sinus rhythm.

Conclusions: MAZE procedure using cryoablation is an effective therapy in patients with paroxysmal or permanent atrial fibrillation who undergo cardiac surgery for other reasons.

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24.3 AN INSTITUTIONAL MODEL TO ASSESS OUTCOMES OF BOTH EPICARDIAL AND ENDOCARDIAL ABLATION PROCEDURES FOR CURE OF ATRIAL FIBRILLATION

*M. Cao, *L.A. Saxon, *M. Cunningham *Cardiovascular Medicine Department, University of Southern California (USC), Los Angeles, USA

Introduction: There is currently no specific FDA catheter labelling for ablation for atrial fibrillation (AF). US centres have a diverse approach to the consent process and electrophysiology and minimally invasive stand-alone surgical programs with curative procedures for AF are often not integrated. New ablation technologies continue to become available for both approaches.

Methods: We devised an institutional approach to AF that utilizes a uniform and combined 1) decision process for determining whether an endo- or epicardial procedure should be recommended 2) consent form 3) comprehensive pre- and post-procedural registry inclusive of surgical approach, ablation source, lesions set and an 4) atrial fibrillation outcomes clinic. Data are collected prospectively from a cohort of consecutive patients referred to either CT surgery or electrophysiology for consideration for an ablation procedure for AF from 2004.

Results: Procedural outcomes on the first fourteen patients with a mean procedural follow up of 8.5 months are shown in the Table. The average age was 59 years and 64% of the group was male. The average LA size was 39 mm. A paroxysmal AF burden was present in 64% of the patients and the remaining 36% had a permanent AF burden. One in four patients in both groups have recurrent AF, unresponsive to antiarrhythmic drugs. Mean hospital stay was 4 days for the epicardial and 2 days for the endocardial approach.

Conclusions: Carefully selected patients have equivalent procedural outcomes with either approach. Mean hospital stays remains longer for those undergoing epicardial access to the left atrium. The model presented allows for a comparative analysis of outcomes.

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24.4 CYBERHEART: TOTAL NON-INVASIVE THERAPY FOR CARDIAC ARRHYTHMIAS USING STEREOTACTIC RADIOSURGERY: ABLATION LESION CREATION

*A. Sharma, *P. Maguire, *D. Wong, *T. Sumanaweera, *J. Marshall, *J. Steele, *L. Fajardo, *P. Takeda, *T. Fogarty *Sutter Medical Research Institute, Sacramento, California, USA

Introduction: Catheter-based techniques for arrhythmia ablations require intravascular intervention with limitations, and potential complications. We used externally focused stereotactic radiation to alter cardiac electrophysiological and histological properties, for the future clinical application of ablating arrhythmias.

Methods: Externally focused radiation of atrial tissue was studied in Hanford-Sinclair mini swine (n = 8) (40–70 kg). The radiation (x-rays, 20–60 Gy) was targeted (pulmonary vein orifice and cavo-tricuspid isthmus) using a computer controlled robotic arm, which directed a linear accelerator (Cyberknife). Cardiac and respiratory motion compensation was used. Post treatment, cardiac assessment with TEE and cardiac mapping with CARTO (Biosense) took place. The animals were euthanized and pathology specimens taken.

Results: All animals survived treatment. Radiation effects appeared to be time- and dose-dependent. Radiation directed at specific areas resulted in uniform attenuation of signal amplitude. No pulmonary vein stenosys was seen. Cardiac function was preserved. No adverse effect was observed in surrounding tissues.

Conclusions: External stereotactic radiosurgery produces focused electrophysiological and histological change. Energy can be directed to any cardiac tissue with 1–2 mm accuracy.

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24.5 MULTIFACTORIAL BENEFICIAL EFFECTS OF THE POLYUNSATURATED FATTY ACIDS IN PATIENTS UNDERGOING AORTOCORONARY BYPASS-GRAFT SURGERY

*E. Rošková, **D. Pella, ***P. Olexa, *M. Studenčan, ***B. Stančák, ****M. Hulman *Dept. of Cardiology, Kosice, Slovakia ***Preventive and Sports Medicine Centre, Medical Faculty, University of PJ.Safarik, Kosice, Slovakia ***Arrhythmology Surgery, Kosice, Slovakia ****Cardiac Surgery, Eastern Slovakian Institute of Cardiovascular Diseases, Kosice, Slovakia

Introduction: Polyunsaturated fatty acids (PUFAs) are known for their positive anti-inflammatory, anti-arrhythmic, anti-thrombotic and hypolipidemic effects. The aim of our study was to assess effects of PUFAs administered to patients planned for aortocoronary bypass-graft surgery (CABG). The incidence of new atrial fibrillation (AF), all post-operative complications and the duration of the stay in hospital were evaluated in both groups.

Methods: Forty-four patients (5 women/39 men) with a mean age of 61 years (43 to 79 years) were included to the study. Two grams of PUFA per day were administered to every second consecutive patient, so 50% (22) of the subjects examined were on active treatment. PUFA therapy was initiated 5 days before the planned CABG and continued until the discharge. The reason for the CABG was a severe coronary heart disease, none had a history of significant valvular disease and or atrial fibrillation. Chi square test and unpaired Student T-test were used for statistical analysis.

Results: New atrial fibrillation occurred in 4 patients within the group of patients treated with PUFA (18,2%). In the other group new AF occurred in 11 patients (50%). This difference was assessed as statistically significant (p = 0,026). All postsurgical complications (febrilities, postperfusion syndrome, bronchopneumonia, prolonged wound healing, pleural effusions, renal function worsening) occurred in the PUFA group significantly less often compared to the non-PUFA patients (9 (40.9%) vs. 16 (72.7%); p = 0,033). The difference in the duration of hospitalization between the two groups was significant as well (9.3 vs. 11.5 days, p = 0.02).

Conclusions: Several positive prognostic effects, such as the reduction of new onset of postoperative atrial fibrillation and other postoperative complications and even the shortening of the duration of hospitalization were found in the PUFA group of CABG patients examined. A small number of patients represented a possible limitation of our study. This is why these preliminary results need to be proven in following larger randomized studies.

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24.6 BIVENTRICULAR EPICARDIAL PACING CONCOMITANT WITH CARDIAC SURGERY IN HEART FAILURE PATIENTS

*P.G. Golzio, *M. Jorfida, *M. Vinci, *A. Chiribiri, *R. Massa, *A.M. Calafiore, *G.P. Trevi *University Divisions of Cardiology and Cardiac Surgery, Molinette Hospital, University of Turin, Italy

Introduction: When biventricular pacing cannot be carried out through the coronary sinus, it can be achieved by means of an epicardial approach. Epicardial implants are often performed as single, second-step procedures in the case of failed coronary sinus approach. We tried to evaluate left ventricular epicardial lead positioning as a first-choice procedure in heart failure patients undergoing concomitant urgent cardiac surgery.

Methods: 13 consecutive epicardial PM were implanted as a first-choice procedure in patients with NYHA IV and EF<35%. These patients underwent urgent surgery for CABGs, mitral valve reconstruction, mitral valve replacement and combined operations. Pacing thresholds, sensing parameters and lead impedances were assessed during surgery (Intra-Operative assessment, IO), within 48 hours and during follow-up (control examinations C1: mean time from implantation 35 days; C2: 116 days; and C3: 186 days).

Results: IO electrical checks often show sub-optimal values for LV, RV and atrial leads. However, these parameters strongly and significantly improve within 48 hours and 30 days, and remain stable during follow-up (p = 0.000). QRS shortens from 192 ± 31 to 150 ± 18 msecs (p = 0.000). Ejection fraction increases form 21 ± 6 to 21.6 ± 7.5% (n.s.). LVESD decreases from 71 ± 13 to 61 ± 8 mm (p = 0.044) and NYHA Class improves (p = 0.000). Mortality during follow-up is very high, approaching 70%, and many deaths are sudden.

Conclusions: LV epicardial lead positioning seems to be reliable, during heart surgery procedures performed for other indications, and electrical checks significantly ameliorate in the early post-operative periods. While QRS, echocardiographic and functional parameters significantly improve, precise evaluation of the effects of biventricular pacing alone is precluded because of the interfering effect of surgery. Because of the high mortality rate of our population, less extensive implantation, through better pre-operative patient selection, seems appropriate. It may be advisable to position only LV leads during concomitant surgery and to defer the implantation of right leads in patients without clinical improvement. In this case, considering the high rate of sudden deaths observed, implanting shock-capable pacing devices seems more appropriate.

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24.7 MAPPING AND ABLATION OF LATE POST-SURGICAL INTRA-ATRIAL REENTRANT TACHYCARDIAS, GUIDED BY 3D GEOMETRY RECONSTRUTION USING CONVENTIONAL CATHETER AND CUTANEOUS PATCHES

*S. Nardi, *C. Esposito, *M.M. Pirrami, *C. Marini, *G. Ranalli, *V. Borghetti, *G. Maglia, *A. Pardini, *G. Ambrosio, *G. Rasetti *Arrhythmia, Electrophysiologic Center and Cardiac Pacing Unit, Thoracic Surgery and Cardiovascular Department, Division of Cardiology, AO S. Maria, Terni, Italy

Introduction: The late recurrence of atrial tachycardia (AT) after cardiac valvular surgery is often due to atriotomy scar or post-inflammatory response. The main drawback of electrophysiologic (EP) criteria is that the reconstruction of a complete circuit is often difficult to achieve. EnSitereg; system NavX™ represents an electro-anatomic (EA) mapping system particularly useful for diagnostic and ablative purposes.

Methods: We utilized the EnSitereg; system in 24/82 consecutive patients who underwent cardiac surgery for valve replacement (12 mitral, eight aortic, and four tricuspid valve), and who developed a late post-surgical anti-arrhythmic drugs (AADs) refractory AT.

Results: The mapping process correlated closely with the anatomical model, EP recordings and fluoroscopic images. AT's operative mechanisms were identified in 20/24 patients as common atrial flutter (14), right lateral wall (five), right septal wall (four), left roof (four) and peri-mitralic (seven) circuits. We successfully ablated all circuits identified and after six months’ FU, 18/20 successfully ablated patients were AT- and AAD-free.

Conclusions: In complex arrhythmias, NavX™ technology provided a realistic geometrical reconstruction and may prove useful in cases where ablation strategy is to be both EP and EA based.

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24.8 COMBINED SURGICAL CRYOABLATION AND LEFT VENTRICULAR REMODELLING FOR THE TREATMENT OF VENTRICULAR TACHYARRHYTHMIAS

*F. Wellens, *R. Beelen, *P. Geelen, *F. Van Praet, *F. Casselman, *I. Degrieck, *H. Vanermen *Cardiovascular Centre OLV Clinic, Aalst, Belgium

Introduction: The aim of this study is to determine the efficacy of combined left ventricular (LV) endoaneurysmorrhaphy and non-mapped intra-operative cryoablation for arrhythmia control in patients with post-infarction LV aneurysm (LVA) and sustained tachycardia (VT).

Methods: Between July 1994 and 2006, 60 patients underwent “blind” cryoablation at the transition zone of scar and viable tissue combined with LV aneurysm repair for malignant VT.

Results: Mean age was 66 years (range, 49–8); 35 patients (58.3%) were functional in NYHA III-IV and 14 (23.3%) presented cardiogenic shock (preintubated). LVA was anterior in 55 (91.6%). Timing of surgery was 32.5 (median) months post-infarction (range, 3 weeks to 20 years). Preoperative ejection fraction was ≤35% and ≤25% in 33 (55%) and 24 (40%) patients respectively; mean end-diastolic volume index was 134.5 (58–302). VT was monomorphic in 37 (61.6%), polymorphic in 5 (8.3%) and incessant VT in 12 (20%) of the patients; ventricular fibrillation (VF) was present in 6 (10%). Patch endoaneurysmorrhaphy was performed in 43 (71.6%). There were 3 (5%) cases of recurrent ventricular arrhythmia (2 and 4 weeks postoperatively). Electrophysiological study (0.5–1 month postoperative) showed freedom from VT indication in 47 (78.3%) patients; VT was inducible in 12 (20%) and led to prophylactic defibrillator implantation. During follow up (average 27.8 months, range 1–117), there was no late recurrence of VT/VF in defibrillator-implanted or in non-implanted patients. There were no arrhythmia related deaths or need for late defibrillator implantation.

Conclusions: In patients presenting VT/VF in the presence of LVA, combined “blind” cryoablation and endoaneurysmorrhaphy offers good short- and mid-term arrhythmia control. The role of the prophylactic defibrillator remains to be determined.

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25. PACEMAKERS: SENSING, PACING THRESHOLD, ALGORITHMS

25.1 SITE-SPECIFIC ATRIAL FIBROSIS IN MYOTONIC DYSTROPHY PATIENTS AND EFFECTS ON ATRIAL PACEMAKER LEAD

*G. Nigro, *P. Vergara, *A.D. Manfredi, *R. Chianese, *A. Prisco, *D. Nicolò, *A. Fontana, *F. Urarro, *D. Andrea, *R. Calabrò *Cardiology Department, Second University of Naples, Naples, Italy

Introduction: Unaffected myocardium in Myotonic Dystrophy type 1 (MD1) patients is progressively replaced by scarring, causing pacemaker (PMK) sensing and pacing defects. The aim of this study was to identify the optimal site for atrial lead implantation.

Methods: Twenty-two consecutive patients (15 males; 32 ± 7 years) necessitating PMK implantation were enrolled in the present study. The atrial pacing lead was positioned in the high lateral right atrial wall (Site A), then in the right atrial appendage (Site B) and finally on the right side of the interatrial septum (Site C). Correct localization was confirmed by fluoroscopic imaging and paced P wave configuration.

Results: Mean pacing thresholds, at a pacing pulse width of 0.5 sec, were: 1.46 ± 0.32 V at Site A, 1.45 ± 0.33 V at Site B and 0.84 ± 0.24 V at Site C. The P wave amplitude was 1.52 ± 0.45 mV at Site A, 1.52 ± 0.49 mV at Site B and 2.60 ± 0.48 mV at Site C. Atrial lead was implanted and fixed at Site C in all patients without complications.

Conclusions: The interatrial septum in MD1 patients seems to be less affected by fibrosis than other sites. To avoid sensing and pacing defects, the atrial lead in MD1 patients may be safely inserted in the interatrial septum using an active fixation lead.

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25.2 ONE-YEAR CHRONIC PERFORMANCE OF FAR-FIELD SIGNAL REDUCTION (FSR) PACING LEADS IN ATRIUM

*J. Sperzel, **G. Froehlig, ***J. Scheiner, ***R. Rooke, ***P. Boileau, ***B. Hallier *Kerckhoff Klinik GmbH, Bad Nauheim, Germany **Universitätskliniken des Saarlandes, Homburg/Saar, Germany ***St. Jude Medical Inc, Sylmar, USA

Introduction: A Far-Field Signal Reduction lead (FSR), based on 1.1-mm tip-to-ring electrode spacing and optimized surface area, has been designed to improve pacemaker therapy by reducing oversensing of ventricular far-field signals (FF) in the atrium. This study evaluated the chronic performance of FSR leads (SJM Tendril 1699T) versus regular pacing leads.

Methods: 25 patients were randomized to receive either a FSR lead or a regular lead (SJM Tendril 1688T). At regular follow ups over one year, pacing and sensing characteristics of the leads were measured and FF sensing threshold tests were performed with a short post ventricular atrial blanking (60 ms).

Results: At one year, FSR lead performance was appropriate, stable, and nearly equivalent to regular pacing leads. FF amplitudes were significantly reduced as 67% FSR leads versus only 30% control group were maintained below 0.1 mV. None of the FSR patients exhibited FF sensing threshold at or above 0.3 mV. FSR leads also demonstrated clinical benefits by decreasing the number of inappropriate mode switches.

Conclusions: These results suggest that the FSR lead can provide improved pacemaker therapy with accurate diagnostic data.

Performance at 1 yearSJM 1688TSJM 1699T
  1. (*p = 0.04; p > 0.1 for all comparisons)

Impedance (Ω)518 ± 102430 ± 85 *
Capture Threshold (V)0.72 ± 0.220.70 ± 0.27
Bipolar sensed P-wave (mV)3.10 ± 1.462.53 ± 0.98
Unipolar sensed P-wave(mV)2.83 ± 1.203.25 ± 1.36

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25.3 EVALUATION OF RIGHT ATRIAL MANUAL UNIPOLAR VERSUS BIPOLAR THRESHOLDS

*J. Sperzel, **C. Butter, ***C. Kennergren, ****S. Goetze, †A. Garg, †S. Gudapakkam, ††A. Doelger, ††A. Koenig, †††M. Biffi *Kerckhoff-Klinik, Bad Nauheim, Germany **Herzzentrum Brandenburg, Bernau, Germany ***Sahlgrenska University Hospital, Gothenburg, Sweden ****Deutsches Herzzentrum Berlin, Berlin, Germany †Boston Scientific CRM, St. Paul, Minnesota, USA ††Boston Scientific, Guidant Europe CRM, Diegem, Belgium †††Policlinico S. Orsola-Malpighi, Bologna, Italy

Introduction: Given the small amplitudes of atrial signals, it is often difficult to discriminate capture/non-capture, especially in a bipolar pacing configuration. A concordance between unipolar and bipolar thresholds would allow to use the more readily found unipolar thresholds in bipolar configurations.

Methods: During device implant/replacement an Acute Study System was connected to the pacing leads. Unipolar and bipolar manual tests were run and the each test was visually classified off-line for capture/fusion/non-capture to determine the pacing threshold.

Results: Data from 34 patients (26 M/8 F;67.7 ± 10.8 yrs) were analyzed. Patients received a dual chamber device (PM/ICD/CRT-P/CRT-D:5/13/6/10) with bipolar atrial leads from four manufacturers. The average unipolar threshold was 0.72 ± 0.38 V, whereas the bipolar threshold was 0.69 ± 0.32 V. As seen from the graph, more patients presented with higher unipolar thresholds. Applying a safety margin of 2X with a 1.0 V minimum to the unipolar thresholds still resulted in a safety margin of at least 0.5 V above the corresponding bipolar thresholds.

Conclusions: The results indicate that it may be feasible to determine unipolar RA thresholds and then apply these thresholds, using a simple safety margin, to a bipolar configuration.

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25.4 COMPARISON OF ATRIAL EVOKED RESPONSE AMPLITUDES USING DIFFERENT SENSING VECTORS IN RIGHT ATRIAL AUTO THRESHOLD

*C. Kennergren, *M. Biffi, **S. Goetze, ***C. Butter, ****A. Garg, ****S. Gudapakkam, †R. Habeler, †E. Vireca, ††J. Sperzel *Sahlgrenska University Hospital, Gothenburg, Sweden *Policlinico S. Orsola-Malpighi, Bologna, Italy **Deutsches Herzzentrum Berlin, Berlin, Germany ***Herzzentrum Brandenburg, Bernau, Germany ****Boston Scientific CRM, St. Paul, Minnesota, USA †Boston Scientific, Guidant Europe CRD, Diegem, Belgium ††Kerckhoff-Klinik, Bad Nauheim, Germany

Introduction: Atrial evoked response (AER) amplitudes are critical in the success/failure of automatic algorithms for determining the RA pacing threshold. Determining an optimum AER sensing vector is critical for maximizing AER amplitude.

Methods: An Acute System was connected to the pacing leads to perform automatic RA threshold tests while recording the surface ECG and AER signals. Data were analyzed off-line by extracting the AER amplitudes for each vector, across all tests and patients.

Results: Data from 35 patients (29 M/6 F; 66.2 ± 11.3 yrs) were analyzed. Patients received a dual chamber device (PM/ICD/CRT-P/CRT-D: 4/11/6/14) with bipolar atrial leads from four different manufacturers. For each patient, the “RARing_to_Can” sensing vector showed a higher average AER amplitude than the “RARing_to_Indifferent”. For the last two patients on the graph, the RARing_to_Indifferent vector had AER amplitudes below the minimum required, resulting in the algorithm failing without a threshold. For these same patients, the RARing_to_Can vector showed higher amplitudes, allowing the automatic tests to run successfully.

Conclusions: This study indicates that the RARing_to_Can vector provides better opportunities for successfully running automatic algorithms for determining RA pacing thresholds than the RARing_to_Indifferent does.

  • image(Figure)

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25.5 VALIDATION OF A RIGHT ATRIAL AUTO THRESHOLD ALGORITHM USING TWO INDEPENDENT ATRIAL EVOKED RESPONSE SENSING METHODS

*M. Biffi, **S. Goetze, ***C. Butter, ****J. Sperzel, †A. Garg, ††D. Bohn, †††E. Vireca, ††††B. Schubert, C. Kennergren *Policlinico S. Orsola-Malpighi, Bologna, Italy **Deutsches Herzzentrum, Berlin, Germany ***Herzzentrum Brandenburg, Bernau, Germany ****Kerckhoff-Klinik, Bad Nauheim, Germany †Boston Scientific CRM, St. Paul, Minnesota, USA ††Boston Scientific CRM, St. Paul, Minnesota, USA †††Boston Scientific, Guidant Europe CRD, Diegem, Belgium ††††Boston Scientific, Guidant Europe CRD, Diegem, Belgium *Sahlgrenska University Hospital, Gothenburg, Sweden

Introduction: The purpose of this study was to validate an automatic algorithm to determine RA pacing thresholds using two atrial evoked response (AER) sensing vectors.

Methods: Using proprietary software, atrial threshold tests were performed while recording surface ECG and AERs. Data was analyzed by visually classifying manual tests and determining the success/failure of automatic tests.

Results: Data from 38 patients (30 M/8 F; 66.8 ± 11.2 yrs) were analyzed. Patients received a dual chamber device (PM/ICD/CRT-P/CRT-D:5/13/6/14) with bipolar atrial leads from four manufacturers. The results are shown in the table. All automatic successful tests were within 0.2 V of the manual thresholds for both vectors. Seven automatic RA tests failed to provide a threshold using the RARing_to_Indifferent vector: 4 due to AER amplitudes below the minimum required and 3 due to signal to artefact (SAR) ratios less than 2. Using the RARing_to_Can vector, the AER amplitudes were higher, showing only the 3 failures due to SAR<2.

Conclusions: This study validated an automatic algorithm to determine RA pacing threshold in >90% of attempted tests within 0.2 V accuracy of the manual threshold using either of the AER vectors discussed above.

Unipolar Manual vs. Automatic ThresholdsAER: RARing_to_IndifferentAER: RARing_to_Can
0–0.2 V66 tests64 tests
> 0.2 V0 tests0 tests
Automatic RATest Failures7 tests3 tests
TOTAL73 Tests67 Tests
SUCCESS RATE90.4%95.5%

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25.6 ANALYSIS OF TWO INDEPENDENT PACE/SENSE CONFIGURATIONS FOR AUTOMATIC CAPTURE VERIFICATION IN THE LEFT VENTRICLE

*M. Biffi, **C. Kennergren, ***J. Sperzel, ****S. Goetze, †M.J. Brooke, †A. Sathaye, ††H. Sjöbacka, ††B. Schubert, †††C. Butter *Policlinico S.Orsola-Malpighi, Bologna, Italy **Sahlgrenska University Hospital, Gothenburg, Sweden ***Kerckhoff-Klinik, Bad Nauheim, Germany ****Deutsches Herzzentrum, Berlin, Germany †Boston Scientific CRM, St. Paul, Minnesota, USA ††Boston Scientific, Guidant Europe CRM, Diegem, Belgium †††Herzzentrum Brandenburg, Bernau, Germany

Introduction: This study compared evoked response (ER) signal characteristics and capture discrimination performance from two Independent Pace/Sense (IPS) configurations.

Methods: Sinus rhythm patients indicated for CRT implantation were enrolled for testing using an external pacing system. LV step-down threshold tests during BiV VVI (10 bpm above intrinsic) pacing were performed: one with LVDistal to Can pacing and LVProximal to Can ER sensing; and another with LVProximal to Can pacing and LVDistal to Can sensing. ER signals were characterized by min. LV ER, max. pacing artifact, amplitude stability, and mean peak timing. Successful capture discrimination was defined as ERmin > 2 mV and min signal-to-artifact ratio >2.

Results: Data were collected and analyzed from patients (Age: 68.9 ± 12.2 years; M/F: 12/3; CRT-P/CRT-D: 6/9) with four types of bipolar LV leads from two manufacturers. Results are shown in the table.

Conclusions: This study showed that LV ER signals are not affected by the cathode location with an IPS configuration and show adequate capture discrimination performance during BiV pacing with bipolar LV leads. The IPS configurations may provide an effective means of implementing LV ACV.

Pacing/Sensing VectorsLVDistal to Can/LVProximal to Can (N = 15)LVProximal to Can/LVDistal to Can (N = 14)p-value
Threshold (V) 1.5 ± 1.5 1.2 ± 1.0NS
Min LV ER (mV) 9.1 ± 4.6 9.0 ± 4.4NS
Max Pacing Artefact (mV) 0.2 ± 0.2 0.3 ± 0.2NS
SARmin80.4 ± 149.187.4 ± 106.4NS
Amplitude Stability0.04 ± 0.050.06 ± 0.05NS
Mean Peak Tmax (ms)40.3 ± 7.437.7 ± 7.1NS
ERmin > 2 mV 15/15 14/14NS
SARmin > 2 15/15 14/14NS
% Successful Pts. 100%100%NS

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25.7 WHICH PATIENTS EXPERIENCE MARKED PACING THRESHOLD FLUCTUATIONS AFTER PACEMAKER IMPLANT WITH AUTOMATIC CAPTURE? INSIGHTS FROM THE ITACA STUDY

*D. Pecora, *F. Moranti, **M. Liccardo, ***P. Pepi, ****S. Orazi, †P. Sartori, ††L. Piraino, †††S.I. Caico, ††††G. Raciti, ‡G.B. Del Giudice *Fondazione Poliambulanza, Brescia; **Osp. S. Maria delle Grazie, Pozzuoli; ***Pres. Osp. Carlo Poma, Mantova; ****Osp. S. Camillo de Lellis, Rieti; †Osp. S. Martino, Genova; ††Osp. Civico, Palermo; †††Osp. di Circolo, Varese; ††††Guidant-Boston Scientific Italia, Milan; ‡Osp S. Giovanni-Addolorata, Rome; Italy

Introduction: Despite the use of ventricular Automatic Capture (AC) in pacemakers (PM), it is not known which patients develop threshold rise during the follow-up, requiring backup pacing to ensure safety. The aim of this study is to find which patients experience ventricular threshold fluctuations >1 V after PM implant.

Methods and Results: Five-hundred and ninety-four patients were examined for a mean period of two months. In 50 patients (8.4%) a maximum difference of at least 1 V was found in daily ventricular threshold measurements. Patients’ characteristics (gender, atrial disease, AV block, coronary artery disease, atrial fibrillation, PM replacement, PM dependence), lead features (chronic, polarity, fixation, impedance, steroid, site) and PM measurements (threshold >1 V, safety backup pacing) were correlated with threshold fluctuations. Patients with fluctuations >1 V showed a higher incidence of safety backup pacing (40% vs. 4% p < 0.001) and were inversely associated only with steroid eluting leads (48% vs. 63%; p = 0.03) and with PM dependency (4% vs. 15% p = 0.03).

Conclusions: Up to 8% of patients implanted with PM experience threshold fluctuations. As clinical variables do not allow us to predict this behaviour, Automatic Capture algorithm is a useful tool to avoid the programming of maximum output in PM patients.

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25.8 PREDICTORS OF CHRONOTROPIC INCOMPETENCE IN DUAL SENSOR PM PATIENTS: IS A DUAL SENSOR APPROPRIATE? INSIGHTS FROM THE DUSISLOG STUDY

*P. Pieragnoli, **M. Landolina, ***E. Moro, ****S. Orazi, †A. Vicentini, ††G. Maglia, †††O. Pensabene, ††††M. Gulizia, ‡G. Raciti, *L. Padeletti *Istituto di Clinica Medica e Cardiologia, Florence; **IRCCS Policlinico S. Matteo, Pavia; ***Osp S. M. dei Battuti, Conegliano; ****Osp S. Camillo de Lellis, Rieti; †Casa di cura Pederzoli, Peschiera del Garda; ††Osp Jazzolino, Vibo Valentia; †††AO Villa Sofia, Palermo; ††††Osp S. Luigi-Currò, Catania; ‡Boston Scientific, Milan, Italy

Introduction: Scant information is available on chronotropic disease predictors in patients implanted with rate responsive devices and on the real benefit of dual sensor in these patients.

Methods: In 105 patients implanted with a rate responsive PM (Insignia, Boston Scientific) dual sensor was compared to single sensor pacing (both XL and MV) for a three month follow-up period. Mean percentage of physical activity, intensity of activity, quality of life (QoL) scores and six minute walk distance (WT) were collected. Results were stratified according to atrial pacing percentage over 60 ppm (AP%, in quartiles), cardiomyopathy, NYHA class and medical therapy.

Results: Only the highest quartile of%AP, representing patients with advanced chronotropic disease, received benefit from dual sensor pacing (QoL: +21 ± 14% p < 0.05; WT: +17 ± 7% p < 0.02). At multivariate analysis these patients were associated with a higher incidence of cardiomyopathy and treatment with anti-arrhythmic or beta-blocking drugs.

Conclusions: Patients undergoing implantation of rate responsive devices, with advanced cardiomyopathy and treated with beta blockers or anti-arrhythmic drugs, show a higher degree of chronotropic incompetence and are likely to receive major benefits from a dual sensor optimized programming.

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26. PM/ICD: SAFETY ISSUES, INFECTION AND LEAD EXTRACTIONS

26.1 SAFETY AND EFFICACY OF MAGNETIC RESONANCE IMAGING (MRI) IN PM/ICD PATIENTS

*P. Lupo, **F. Sardanelli, **M. Quarenghi, *G. De Ambroggi, *S. Foresti, *L. Vitali Serdoz, *R. Cappato *Arrhythmias and Electrophysiology Center, Milan, Italy **Department of Radiology, IRCCS Policlinico San Donato, University of Milan, Milan, Italy

Introduction: Implanted pacemakers and defibrillators have long been regarded as an absolute contraindication for MRI. Nevertheless, previous studies have suggested the feasibility and safety of MR imaging (1.5 T) in PM patients.

Methods: After informed consent, 17 patients previously implanted with PM/ICD (7 PM, 10 ICD) and with a strong willingness towards MR examinations were included (3 brain, 2 spine, 8 heart, 1 breast, 3 abdomen). We excluded only PM-dependant patients and those implanted before 2000. Before MR, we collected the battery and lead parameters and disabled all the therapies (ATP and shocks). The MR examinations were performed at 1.5 T (Sonata, Siemens, Germany).

Results: During the MR examinations we did not observe any relevant clinical modification. The PM/ICD interrogation showed neither modifications nor alert warnings. The MRI was fully diagnostic in most patients. During the follow-up (1–6 months), the patients resulted free from any symptom which could be related to a pacemaker dysfunction and the PM/ICD parameters did not change.

Conclusions: Our results show that, under carefully controlled conditions and with an appropriate selection of candidates, patients with implanted devices of last or next generation can be safely and efficaciously studied with MR imaging. Moreover, it can help to understand the technical tools (MR protocols and PM/ICD program) needed to avoid clinical and device complications.

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26.2 CAN ALL MRI SCANS BE CONSIDERED SAFE? METHODS TO REDUCE DISTAL TIP LEADWIRE HEATING DURING MRI SCANS OF PACEMAKERS AND ICDS

*R. Stevenson, *W. Dabney, *C. Frysz *Research and Development, Greatbatch, Inc., Clarence, New York, USA

Introduction: Under certain pacemaker implant and MRI scan conditions, maximum RF field coupling to leadwires occurs, which can cause significant distal tip heating. Variables include implanted lead length, lead position, patient position in the MRI bore, and MRI scan settings.

Methods: Prototype distal tip band-stop filter chips were constructed to be resonant at the MRI RF pulsed frequency. The filter creates high impedance at the MRI RF pulsed RF frequency, thereby significantly reducing currents in implanted leadwires. Filter prototypes were built and tested in MRI scanners and compared with unfiltered control leads. Temperature measurements were recorded by fiber optic probes in a gel phantom.

Results: In a worst-case condition, the distal tip of the control lead wire heated up to 57°C. With the filter chip added, the distal tip heated up to less than 3°C.

Conclusions: Addition of the MRI Chip at the distal TIP of pacemaker leadwires significantly reduces distal tip heating and provides a high margin of safety, particularly when MRI scan and implant variables combine into a “worst-case” RF coupling scenario.

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26.3 MRI SCANNING OF PACEMAKERS AND ICDS: DATA ON LEADWIRE HEATING, FORCE, TORQUE AND IMAGE ARTEFACT

*R. Stevenson, *W. Dabney, *C. Frysz *Research and Development Department, Greatbatch, Inc., Clarence, New York, USA

Introduction: MRI is currently contra-indicated for pacemaker and ICD patients. Of concern is the potential for overheating of leadwires, force and torque on the implanted device, and image artefacts that could render the MRI scan useless.

Methods: Heating measurements of leadwires were performed in a 1.5 T scanner in a gel phantom using multiple fibre optical probes. Leads of varying lengths were connected to a pacemaker and were placed in various positions inside the MRI bore. Force and torque of pacemaker/ICD components were measured using non-ferromagnetic force transducers. Image artefact of various components was evaluated following ASTM F-2119.

Results: Leadwire heating measurements show that in certain “worst case” MRI scan protocols and leadwire positions distal tip temperatures of up to 57 degrees C can occur. Force and torque measurements were shown to be minimal. However, MRI image distortion was as large as 30 cm.

Conclusions: For certain “worst case” lead wire configurations and MRI scan settings temperatures of up to 57 degrees C were recorded. Force and torque were of low concern, but image artefact proved to be of significant concern.

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26.4 BACTERIOLOGICAL POCKET AND PIN/TIP CULTURE OF INFECTED PACEMAKER AND DEFIBRILLATOR LEADS

*P.G. Golzio, **M.G. Bongiorni, ***V. Veglio, ****E. Gaido, *M. Vinci, *G.P. Trevi *University Department of Cardiology, Molinette Hospital, Turin, Italy **Interventional Arrhythmology, Cardiac-Toracic Dept, Cisanello Hospital, Pisa, Italy ***Division of Infectious Disease, Amedeo di Savoia Hospital, Turin, Italy ****Microbiology Dept, Molinette Hospital, Turin, Italy

Introduction: In recent years the incidence of pacemaker and defibrillator lead infection has increased greatly. Patients admitted for local symptoms involving the device pocket are often treated conservatively, but rarely heal. We carried out a microbiologic assessment on samples from blood, pocket, lead pin and tip in cases of suspected infection.

Methods: Between May 2003 and June 2006, at our Centre, 72 leads were extracted from 39 patients, of which 87.5% had indication of infection. Prior to explantation, patients affected by local infection, chronic draining sinus or sepsis underwent a blood culture and pocket samples (swabs and tissue specimens). After extraction, both lead tip and pin were also examined.

Results: Lead samples were more sensitive than pocket samples (92.5% of culture positives vs. 59.1% recorded for pocket samples; p = 0.000). Lead pins proved positive not only in 100% of local infections, but also in 92.5% of chronic draining sinus cases, while pocket sample cultures were positive only in 60% of these patients. Concordance between bacterial isolates from pocket and lead, and from pocket and pin is quite low, approaching 45%, while concordance between bacterial isolates within the lead (from pin and tip) is quite high, approaching 70%. Concordance between bacterial isolates from lead and blood, and mainly from tip and blood is very high, approaching 80–85%. Among isolated bacteria strains, concordance for Staph. aureus is very high, while for Gram+ flora it practically nil.

Conclusions: Lead samples are more sensitive than pocket samples for infection diagnosis. They should therefore always be taken, so that appropriate antibiotic therapy can be undertaken. Concordance analysis reveals that bacterial isolates from the pocket may be due, at least to some extent, to a contamination effect, while bacterial isolates from the lead may be more clearly associated to a real infection. Our results demonstrate that chronic draining sinus, with culture-negative local analyses, is often sustained by an infection. This emphasises the need for awareness of the limited efficacy of reparative operations and justifies a less conservative approach with regard to extraction procedures.

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26.5 BACTERIOLOGICAL ASSESSMENT OF INFECTED PM/ICD LEADS

*P.G. Golzio, **M.G. Bongiorni, *M. Vinci, ***V. Veglio, ****E. Gaido, *G. P. Trevi *University Cardiology, Molinette Hospital, Turin, Italy **Interventional Arrhythmology, Cardiac-Toracic Dept, Cisanello, Pisa, Italy ***Division of Infectious Disease, Amedeo di Savoia Hospital, Turin, Italy ****Microbiology Department, Molinette Hospital, Turin, Italy

Introduction: It has been proven that untreated lead infections have very serious consequences. We carried out a microbiologic assessment, in order to identify the prevalent strains of bacteria responsible for lead infections, so as to delineate an effective therapeutic protocol.

Methods: Between May 2003 and June 2006, at our Centre, 72 leads were extracted from 39 patients, 87.5% of whom had indication of infection. After extraction, samples of the leads suspected of infection were sent to the microbiology department for examination.

Results: Staph. epidermidis was the most frequently isolated bacterial strain (37.7%), followed by Gram+ flora (16.1%), Staph. aureus (14.3%), Candida parapsilosis (5.4%), Staph. schleiferi (5.4%), Corynebacterium species and Staph. hominis (3.6%). Cultures were negative in about 14.3% of samples. Retained sensitivity to antibiotics was as follows: teicoplanin/vancomycin 100%; doxicyclin 96%; amikacin 94%; piperacillin−tazobactam 58%; co-trimoxazole 78%; gentamycin 65%; quinolones 47%; rifampicin 44%; cephalosporins 25% and oxacillin 25%. Sub-analysis of resistance in various clinical indications showed that, in cases of sepsis, sensitivity to glycopeptides and amikacin was retained (about 100%) and, to a lesser degree, also to doxicyclin (80%). On the basis of the time elapsed prior to referral for lead extraction, we arbitrarily divided the infections into recent (i.e. ≤ 3 months) and chronic infections (i.e. > 3 months). With the only exception of doxicyclin, an increase in time prior to referral for lead extraction was associated with a significant increase in antibiotic resistance. Staph. hominis and epidermidis showed very high antibiotic resistance.

Conclusions: Our data point out a poor susceptibility to antibiotics of the bacteria associated with pacemaker-related infections, and also show that local infections not resolved with usual antibiotics are often sustained by methicillin-resistant strains (about 75% in our case series). Therefore, systemic antibiotics, preferentially glycopeptides, in full-regimen doses, must not be delayed in such patients. It should, however, be borne in mind that the mainstay of the management of relapsing infections is the complete removal of the implanted system.

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26.6 EXCIMER LASER ASSISTED PERCUTANEOUS PM/ICD LEAD EXTRACTION USEFULNESS TO COMPLETELY REMOVE SURGICALLY DAMAGED LEAD PARTS

*M.T. Lucciola, *M. Casella, *A. Dello Russo, *G. Pelargonio, *R. Biddau, *M.L. Narducci, *A. Sparagna, *C. Bisceglia, *P. Zecchi, *F. Bellocci, *A. Martino *Cardiovascular Medicine Department, Catholic University of the Sacred Heart, Rome, Italy

Introduction: We present our experience with Excimer Laser-assisted technique in the subset of percutaneous extraction of leads damaged during surgical removal attempts.

Methods and Results: From January 2006 to January 2007, 4 patients (mean age 60.5) were referred to Our Centre because of PM/ICD-related infection with surgical extraction indication. Total number of leads was 7: 3 atrial and 4 ventricular leads, with 1 double-coiled ICD lead; mean leads implantation time was 158.6 months. All leads were cut at superior cava vein level and their distal parts were surgically removed; however, strong adherences at subclavian vein angle made it impossible to remove their proximal parts. A percutaneous intervention using Excimer Laser technique was then attempted: such intervention was differed for the first patient, whereas in the others it was performed simultaneously to surgery by a skilled equipe in reverse stand-by. All 6 leads were completely extracted without complications (mean time 17 min).

Conclusions: Excimer Laser-assisted lead extraction is a safe and successful procedure to extract PM and ICD lead parts that surgical intervention failed to remove, even simultaneously to surgery.

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26.7 PM/ICD LEAD EXTRACTION: A NEW SINGLE-CENTRE EXPERIENCE

*P.G. Golzio, **M.G. Bongiorni, *M. Vinci, *G.P. Trevi *University Cardiology, Molinette Hospital, Turin, Italy **Interventional Arrhythmology, Cardiac-Thoracic Dept, Cisanello Hospital, Pisa, Italy

Introduction: Over the last few years, an increasingly widespread use of permanent cardiac stimulation devices for the therapeutic treatment of rhythm disturbances has been closely followed by an increase in the number of device-related complications requiring lead extractions. This study reports our experience in lead extraction.

Methods: Between May 2003 and June 2006, at our centre, 72 leads were extracted from 39 patients (27 male, age 26–85, mean 70.9 ± 13.5 years, age of implant range 1–312 months, mean 48.9 ± 49.4 months, n° of repair operations prior to the extraction procedure 1.6 ± 1.5, range 0–5, active anchoring 16%, 28 atrial, 35 ventricular, 2 VDD and 7 defibrillator leads). Clinical indications for extraction were: sepsis (25%), pocket infection (26.4%), chronic draining sinus (36.1%), PM/ICD malfunction (6.9%) and interference with other systems (2.8%). Manual traction was used for 52.8% of leads and dilation/countertraction for 47.2%. Success was completely achieved in 97.2% and partially in 1.4%. Only one lead (1.4%) was not extracted. Manual traction alone was effective in 52.8% of leads and dilation in 96.9%, thus achieving a total success rate of 97.2% through the sequential use of traction followed by dilation. Local anaesthesia was effective in 80.6%, while sedation by an the anaesthetist was necessary only in 19.4%. Acute complications were: non-sustained ventricular tachycardia (6.9%), asymptomatic (11.1%) and symptomatic hypotension (5.6%); perioperative treatments were: volume expansion (40.3%), drugs (22.2%) and transfusions (13.9%).

Results and Conclusions: The results obtained show that the choice of carrying out this delicate procedure was rewarded by a high success rate in terms of both a high percentage of successful operations and a limited number of recorded complications. The methods utilized, involving manual traction with the use of a locking stylet and dilation through polypropylene sheaths, were able to treat and resolve even the most complex cases.

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26.8 LEARNING CURVE IN LEAD EXTRACTION: EXPERIENCE OF A NEW SINGLE DEDICATED CENTRE AND COMPARISON BETWEEN EXTRACTION OUTCOMES IN THE FIRST 6 MONTHS AND LATER

*P.G. Golzio, *M.G. Bongiorni, *M. Vinci, *G.P. Trevi *University Dept of Cardiology, Ospedale Molinette, Turin, Italy *Cardio−Thoracic Dept, Ospedale di Cisanello, Pisa, Italy

Introduction: As we only recently started PM and ICD lead explantation, we deemed it appropriate to perform a quality assessment of the procedures carried out at our centre, by comparing extraction outcomes in the first six months and later.

Methods: Between May 2003 and June 2006, at our centre, 72 leads were extracted from 39 patients (27 males, age 26 − 85 years, mean 70.9).

Results: Comparison between the first six months and the following months, with regard to continuous variables, revealed no significant differences in patients’ ages (72.3 vs 70.7 years), number of leads explanted per patient (2.3 vs 2.2), number of reparative operations prior to extraction (1.4 vs 1.5), manual traction time (58” vs 56”) or number of sheaths required per lead (2.0 vs 2.5). By contrast, differences in other variables were statistically significant: time from previous implantation (15.7 vs 54.3 months, p = 0.022), operating room time (2 h:12 m vs 4 h:13 m, p = 0.000), procedure time (0 h:56 m vs 2 h:03 m, p = 0.011), lead mobilization time (0 h:19 m vs 0 h:50 m, p = 0.001), extraction time (0 h:07 m vs 0 h:29 m, p = 0.011), dilation time (0 h:01 m vs 0 h:22 m, p = 0.004) and fluoroscopy time (0 h:05 m vs 0 h:15 m, p = 0.030). On considering nominal variables, values such as patient sex, referring centre, type of venous access, lead characteristics (type, polarity, insulation, fixation), operative results, acute and chronic complications and the treatment adopted did not show significant differences. By contrast, we found significant differences for other variables: need for temporary PM after procedure (20 vs 98.4%, chi-square 0.000), drug administration (0 vs 25.8%, p = 0.000) and effectiveness of traction alone (80 vs 48.4%, p = 0.037).

Conclusions: In the first six months, procedural difficulty was less for “a priori” selection of explantation patients. However, comparison between the first six months and the following months yielded positive results, in terms of both operating success and limited number of procedural complications. These positive results lasted despite the operating conditions becoming more complex in the later months, owing to increased implant “age” and non-selected indications for extraction.

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27. RV APICAL PACING: EFFECTS AND ALTERNATIVE SITES OF STIMULATION

27.1 THE “SENTINEL” PACE-MAKER IN AV CONDUCTION DISEASE

*F. Biscione, *C. Pignalberi, *A. Totteri, *F. Lo Bianco, *A. De Vita, *G. Altamura *Ospedale S. Giacomo, Rome, Italy

Introduction: VVI stimulation is not inferior to DDD in terms of survival. Electrophysiologists can choose DDD or VVI PMs in patients (pts) with minor AV conduction pathology. We retrospectively reviewed our experience of the use of VVI “sentinel” PM.

Methods: We implanted 48 VVI PMs in pts with II or paroxysmal III AV block symptomatic for syncope.

Results: During follow-up of 20 ± 17 m, 2/48 pts had syncope unrelated to arrhythmias. One patient developed heart failure. In 2 pts, ventricular stimulation accounted for 100% of the time and up-grading to a DDD PM was proposed. Three pts had a ventricular pacing grade >40%, but remained free from heart failure. In the remaining pts, the ventricular pacing grade was 1.3 ± 1.1% (range 0.1%–4.2%). AF occurred in 5 pts. Three were hospitalized: 2 for up-grading and 1 for heart failure.

Two venous thromboses were recorded.

Conclusions: The total cost was €60340 (€1257/patient). If all pts had been initially implanted with DDD PMs, the total cost would have been €163300 (€3402/patient).

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27.2 THE INTRINSIC RV TRIAL IN PERSPECTIVE: A EUROPEAN INTERPRETATION OF THE DATA

*S. Favale, *G. Grandinetti, *F. Nacci, **S. Moore, ***L. Gering, ****M. Rosenbaum, †G. Raciti, ††J.D. Day, †††B. Olshansky *A.O. Policlinico Consorziale, Bari, Italy; **North Ohio Research, Ltd (S.M.), Elyria, Ohio, USA; ***Owensboro Mercy Health System, Owensboro, Ky, and Riverview Hospital, Noblesville, Indianapolis, USA; ****Cardiac Arrhythmia Service (M.R.), Ft. Lauderdale, Florida, USA; ††Utah Heart Clinic Arrhythmia Service (J.D.D.), LDS Hospital, Salt Lake City, Utah, USA; †††University of Iowa Hospitals (B.O.), Iowa City, Iowa, USA; †Guidant-Boston Scientific, Milan, Italy

Introduction: Reimbursements records indicate that a provider implanting any ICD other than a single chamber device for primary prevention must justify the medical necessity for a more advanced ICD. Aim is to show how INTRINSIC RV study results may help to justify this choice.

Methods and Results: The INTRINSIC RV randomized study hypothesis is that DDDR programming with AV Search Hysteresis (AVSH) (60 to 130 ppm) is not inferior to a VVI (40 ppm) programming. Primary endpoint was all-cause mortality and heart failure hospitalization. The trial met the primary endpoint (p < 0.001) showing a trend to a superiority of DDDR AVSH over VVI pacing. Patients with the best results were those having RV pacing percentages from 10% to 19%.

Conclusions:The notion that dual-chamber programming poses an inherent safety risk is incorrect. Whereas current guidelines are less specific for DDD ICD indication, DDD pacing with AVSH shows that responses with dual-chamber programming were as good, if not better, than single chamber programming. Dual chamber programming should definitely be considered for suitable patients.

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27.3 PREDICTION OF ATRIAL AND VENTRICULAR ELECTRO-MECHANICAL DELAYS FROM SURFACE ECG FOR OPTIMIZATION OF PACEMAKER AV TIMING

*R. Chirife, **J. Pastori, **H. Mosto, *M. Arrascaite, ***A. Sambelashvili * Hospital Fernandez, Buenos Aires, Argentina ** Hospital Ramos Mejía, Buenos Aires, Argentina ***Medtronic Inc, Minnesota, USA

Introduction: The purpose of pacemaker atrio-ventricular (AV) delay optimization is to restore physiological timing between left atrial and left ventricular contractions. In order to calculate the optimal AV, two intervals are needed: 1. Sensed or paced atrial transport delay (ATDs and ATDp respectively), defined as time from right atrial P-wave sensing or pacing, to the end of left atrial transport. 2. Interventricular delay (IVD), related to the duration of pre-ejection interval (PEI). The study intended to test the hypothesis that ATDs and ATDp could be predicted from sensed P-wave (Ps) and paced P-wave (Pp), and RV-sensed and RV-paced pre-ejection intervals (PEIs and PEIp respectively) could be predicted from sensed and paced QRS duration (QRSs and QRSp respectively), determined using 3-lead surface ECGs.

Methods: Thirty-seven patients (Pts) aged 63.5 ± 15.5 years, 64% males, all with previously implanted DDD pacemakers, were studied by Doppler echocardiography and surface ECG obtained with a pacemaker programmer. ECG measurements included P-wave duration (Ps, Pp) and QRS duration (QRSs and QRSp), excluding Pts with bundle branch block. Echo-Doppler measurements included atrial transport delay (ATDs and ATDp), and PEIs and PEIp, measured from the onset of QRSs or QRSp to the onset of Doppler aortic flow. Regressions between the electrocardiographic and corresponding echo-Doppler intervals were calculated.

Results: These are shown in the table below.

Conclusions: 1. Atrial transport time and pre-ejection interval are predictable from simple surface ECG measurements. 2. These measurements may allow programming optimal AV delays in DDD and CRT devices without need of Doppler echocardiography.

EquationsR valueT Test (P value)
ATDs = 1.18 *Ps + 29.20.81<0.0001
ATDp = 0.89 *Pp + 68.90.84<0.0001
PEIs = 0.69 *QRSs + 23.10.94  0.0002
PEIp = 0.74 *QRSp + 360.87<0.0001

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27.4 SHOULD WE PROGRAM AN ADAPTIVE RATE AV DELAY IN AV BLOCK PACING?

*B. Ismer, *C. Melzer, *T. Körber, *H. Theres, *C.A. Nienaber, *G. Baumann *Cardiology Divisions of the University Hospital Rostock, Rostock, Germany *The Charite, Berlin, Germany

Introduction: The haemodynamically optimal AV delay (AVD) is the net effect of electrical and electromechanical time intervals. By diastolic optimization, AVD can principally be defined as the sum of individual implant-related inter-atrial conduction time (IACT), duration of left atrial electromechanical action (LA-EAClong) and the duration of the left ventricular latency period (SV-EACshort) using AVD = IACT + LA-EAClong− SV-EACshort. The aims here are to measure the influence of the AVD determinants on optimal AVD during rest and exercise in 3rd degree AV block (AVB) patients.

Methods: By simultaneously recording transmitral flow velocity and an oesophageal left atrial electrogram on the echo monitor, we separately measured the duration of the AVD determinants and calculated the optimal AVD in 20 AVB patients (11 f, 9 m, 62.7 ± 12 y, EF>45%) during rest and submaximal ergometric exercise.

Results: During mean rate increase of 31.5 ± 9.9 bpm induced by exercise load of 71 ± 9 W, both mean values of the three determinants and the resulting optimal AVDs differed without significance. IACTs in VDD and DDD operation varied by 2.3 ± 8.4 ms and 1.4 ± 8.8 ms respectively. Major variations of -8.4 ± 32.7 ms were found in duration of LA-EAClong. SV-EACshort varied by –2.6 ± 21.8 ms. The resulting AVD variations were -3.5 ± 33.3 ms and -4.3 ± 37.8 ms in VDD and DDD operation, respectively.

Conclusions: 1. AVD variation during exercise is mainly caused by superimposing variations of the two electromechanical time intervals. 2. In a typical cohort of AVB patients, the observed small rate-responsive AVD variations justify switching off the rate adaptive AVD.

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27.5 EFFECT OF RIGHT VENTRICULAR APICAL PACING IN PREVIOUS MYOCARDIAL INFARCTION PATIENTS

*C. Muto, **L. Ascione, *M. Canciello, *G. Carreras, **R. Iengo, *L. Ottaviano, **M. Accadia, *R. Calvanese, **E. Celentano, ***C. Ciardiello, *B. Tuccillo *Unità Operativa di Elettrofisiologia ed Elettrostimolazione, Ospedale S.M. di Loreto, Naples, Italy **Unità Operativa di Ecocardiografia, Ospedale S.M. di Loreto, Naples, Italy ***Boston-Guidant, Italy

Introduction: Vast information is available on the possible negative effects of apical right ventricular pacing (RVP) in pace-maker patients, which may be closely associated with the worsening of heart failure. Very limited data are available on the effects of RVP in patients with history of myocardial infarction (MI).

Methods and Results: We screened 115 post MI consecutive patients. Data matching by age, left ventricular ejection fraction and MI site was performed to select two groups (with and without pace-maker): 29 pts and 49 controls were thus selected. During a median 54 month follow-up we observed no difference in mortality among the two groups. Multivariate analysis showed that no variable was a significant predictor of mortality. Echocardiography data showed a reduction of left ventricular ejection fraction for the pace-maker group (from 51 ± 10 to 39 ± 11 p < 0.01) and no variation in the control group (from 57 ± 8 to 56 ± 7 p = 0.98). A similar trend was also verified for both systolic and diastolic diameters and volumes.

Conclusions: The study suggests that the right ventricular apical stimulation may have a detrimental role in the left ventricular remodelling after MI.