There are no conflicts of interest to report for any author.
Tpeak – Tend and Tpeak – Tend/QT Ratio as Markers of Ventricular Arrhythmia Risk in Cardiac Resynchronization Therapy Patients
Article first published online: 27 OCT 2012
©2012, The Authors. Journal compilation ©2012 Wiley Periodicals, Inc.
Pacing and Clinical Electrophysiology
Volume 36, Issue 1, pages 103–108, January 2013
How to Cite
BARBHAIYA, C., PO, J. R. F., HANON, S. and SCHWEITZER, P. (2013), Tpeak – Tend and Tpeak – Tend/QT Ratio as Markers of Ventricular Arrhythmia Risk in Cardiac Resynchronization Therapy Patients. Pacing and Clinical Electrophysiology, 36: 103–108. doi: 10.1111/pace.12031
- Issue published online: 9 JAN 2013
- Article first published online: 27 OCT 2012
- Manuscript Revised: 12 AUG 2012
- Manuscript Accepted: 12 AUG 2012
- Manuscript Received: 19 APR 2012
- Tpeak–Tend interval;
- transmural dispersion of repolarization;
- implantable cardioverter-defibrillator therapy;
- cardiac resynchronization therapy
Cardiac resynchronization therapy (CRT) increases transmural dispersion of repolarization (TDR) and can be pro-arrhythmic. However, overall arrhythmia risk was not increased in large-scale CRT clinical trials. Increased TDR as measured by Tpeak –Tend (TpTe) was associated with arrhythmia risk in CRT in a single-center study. This study investigates whether QT interval, TpTe, and TpTe/QT ratio are associated with ventricular arrhythmias in patients with CRT-defibrillator (CRT–D).
Post-CRT–D implant electrocardiograms of 128 patients (age 71.3 years ± 10.3) with at least 2 months of follow-up at our institution's device clinic (mean follow-up of 28.5 months ± 17) were analyzed for QT interval, TpTe, and TpTe/QT ratio. Incidence of ventricular arrhythmias was determined based on routine and directed device interrogations.
Appropriate implantable cardioverter-defibrillator therapy for sustained ventricular tachycardia or ventricular fibrillation was delivered in 18 patients (14%), and nonsustained ventricular tachycardia (NSVT) was detected but did not require therapy in 58 patients (45%). Patients who received appropriate defibrillator therapy had increased TpTe/QT ratio (0.24 ± 0.03 ms vs 0.20 ± 0.04, P = 0.0002) and increased TpTe (105.56 ± 20.36 vs 87.82 ± 22.32 ms, P = 0.002), and patients with NSVT had increased TpTe/QT ratio (0.22 ± 0.04 vs 0.20 ± 0.04, P = 0.016). Increased QT interval was not associated with risk of ventricular arrhythmia. The relative risk for appropriate defibrillator therapy of TpTe /QT ratio ≥ 0.25 was 3.24 (P = 0.016).
Increased TpTe and increased TpTe/QT ratio are associated with increased incidence of ventricular arrhythmias in CRT–D. The utility of TpTe interval and TpTe/QT ratio as potentially modifiable risk factors for ventricular arrhythmias in CRT requires further study.
(PACE 2013; 36:103–108)