Time-dependent effect of cardiac resynchronization therapy on ventricular repolarization and ventricular arrhythmias

Abstract

Transmural dispersion of repolarization and the number of patients with VT/VF decreased over time after CRT. Patients with reverse remodelling demonstrated a lower rate of VT/VF and a greater time-dependent reduction of TDR.

Electro-echocardiographic Indices to Predict Cardiac Resynchronization Therapy Non-response on Non-ischemic Cardiomyopathy

“…However, CRT totally changes left ventriclular direction of depolarization and repolarization since its epicardial pacing, leading to TDR increasing36. It was reported that occurrence of tachycardia was higher in early stage of CRT implantation37. In this study, compared to baseline, TpTe and QT which reflect the degree of TDR were significantly increased within 72 h after CRT implantation (100 ± 20 ms vs. 119 ± 24 ms, and 446 ± 58 ms vs. 455 ± 56 ms respectively, p < 0.01, indicating that CRT increases the dispersion of repolarization and has potential to cause arrhythmia in the early stage (Fig.…”

Long‐term effects of cardiac resynchronization therapy on electrical remodeling in heart failure—A prospective study

“…Reverse electrical remodeling: The present study demonstrates that CRT reduces paced QRS duration as well as TDR at 1‐year postimplantation. The magnitude of reduction in TDR is significantly greater in high responders compared with low responders, as demonstrated previously . The mechanism of reverse electrical remodeling due to CRT has not been fully elucidated.…”

“…Itoh et al. demonstrated time‐dependent reduction in ventricular arrhythmias in patients with CRT, with greater reductions in CRT responders as opposed to nonresponders . They also observed that Tp‐e 1 week after CRT implantation was significantly higher compared to baseline.…”

Impact of cardiac reverse remodeling after cardiac resynchronization therapy assessed by myocardial perfusion imaging on ventricular arrhythmia

“…17 Episodes of VT and/or VF detected by the implanted device were validated by two electrophysiologists. 18,19 Electrocardiography (ECG) All patients received two intrinsic ECGs, one was performed before the CRT and the other was performed after transient turn-off of CRT for about 30 minutes before. Intrinsic QRS duration (iQRSd) was measured from the initial to the end of QRS wave.…”