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Biophysical Parameters During Radiofrequency Catheter Ablation of Scar-Mediated Ventricular Tachycardia: Epicardial and Endocardial Applications via Manual and Magnetic Navigation
Version of Record online: 24 JUL 2014
© 2014 Wiley Periodicals, Inc.
Journal of Cardiovascular Electrophysiology
Volume 25, Issue 11, pages 1165–1173, November 2014
How to Cite
BOURKE, T., BUCH, E., MATHURIA, N., MICHOWITZ, Y., YU, R., MANDAPATI, R., SHIVKUMAR, K. and TUNG, R. (2014), Biophysical Parameters During Radiofrequency Catheter Ablation of Scar-Mediated Ventricular Tachycardia: Epicardial and Endocardial Applications via Manual and Magnetic Navigation. Journal of Cardiovascular Electrophysiology, 25: 1165–1173. doi: 10.1111/jce.12477
Supported by the NHLBI (R01HL084261) to K. Shivkumar.
Dr. Shivkumar is an unpaid scientific advisor to Topera and is a corporate board member of BioSig. UCLA has received EP fellowship support from Biosense Webster, St. Jude Medical, Medtronic, and Boston Scientific. Other authors: No disclosures.
- Issue online: 27 OCT 2014
- Version of Record online: 24 JUL 2014
- Accepted manuscript online: 20 JUN 2014 06:31AM EST
- Manuscript Accepted: 28 MAY 2014
- Manuscript Received: 27 APR 2014
- NHLBI. Grant Number: R01HL084261
- ventricular tachycardia;
Ablation Effectiveness and Biophysical Parameters
There is a paucity of data on biophysical parameters during radiofrequency ablation of scar-mediated ventricular tachycardia (VT).
Methods and Results
Data were collected from consecutive patients undergoing VT ablation with open-irrigation. Complete data were available for 372 lesions in 21 patients. The frequency of biophysical parameter changes were: >10Ω reduction (80%), bipolar EGM reduction (69%), while loss of capture was uncommon (32%). Unipolar injury current was seen in 72% of radiofrequency applications. Both EGM reduction and impedance drop were seen in 57% and a change in all 3 parameters was seen in only 20% of lesions. Late potentials were eliminated in 33%, reduced/modified in 56%, and remained after ablation in 11%. Epicardial lesions exhibited an impedance drop (90% vs. 76%, P = 0.002) and loss of capture (46% vs. 27%, P < 0.001) more frequently than endocardial lesions. Lesions delivered manually exhibited a >10Ω impedance drop (83% vs. 71%, P = 0.02) and an EGM reduction (71% vs. 40%, P < 0.001) more frequently than lesions applied using magnetic navigation, although loss of capture, elimination of LPs, and a change in all 3 parameters were similarly observed.
VT ablation is inefficient as the majority of radiofrequency lesions do not achieve more than one targeted biophysical parameter. Only one-third of RF applications targeted at LPs result in complete elimination. Epicardial ablation within scar may be more effective than endocardial lesions, and lesions applied manually may be more effective than lesions applied using magnetic navigation. New technologies directed at identifying and optimizing ablation effectiveness in scar are clinically warranted.