ABSTRACT
Objective: Cardiac resynchronization therapy defibrillator (CRT-D) increases ventricular transmural dispersion of repolarization (TDR). Our work evaluated the relationship between QTc interval of TDR indicators, TpTe, TpTe/QTc ratio and rapid ventricular arrhythmia in patients with CRT-D. Methods: A total of 160 consecutive patients who received CRT-D implantation in our hospital from 2011-01 to 2013-03 were studied. The immediate post operative ECG was collected to analyze lead V5 QTc interval, TpTe and TpTe/QTc ratio for assessing its TDR. The patients were divided into 2 groups: Treatment group, the patients with ventricular tachycardia or ventricular ifbrillation received CRT-D,n=30 (18.7%) and Non-treatments group,n=130 (81.3%). All patients were followed-up for (20 ± 10) months and the rapid ventricular arrhythmia was recorded by CRT-D devices. Results: The patients in Treatment group had increased TpTe/QTc (0.24 ± 0.05) vs (0.20 ± 0.04, and TpTe (119 ± 30) ms vs (95 ± 20) ms, bothP<0.001. The QTc interval was similar between 2 groups (480 ± 60) ms vs (470 ± 70) ms,P=0.6 and QTc interval was not related to the risk of CRT-D requirement. The sensitivity and speciifcity for TpTe/QTc ≥ 0.25 predicting the risk of ventricular arrhythmia in CRT-D patients were at 47% and 91%, while TpTe ≥ 120 ms were at 40% and 95%respectively. The post CRT-D surviving curve analysis indicated that TpTe/QTc ratio and TpTe could predict the prognosis in relevant patients,P<0.001. Conclusion: The elevated TpTe and TpTe/QT ratio may increase the incidence of CRT-D requirement in patients with ventricular arrhythmia after resynchronization.