Depolarization and repolarization dynamics after His-bundle pacing: Comparison with right ventricular pacing and native ventricular conduction

Background The current study aimed to evaluate changes in electrical depolarization and repolarization parameters after His-bundle pacing (HBP) compared with right ventricular pacing (RVP) and its association with ventricular arrhythmia (VA). Methods Forty-one patients (13 with HBP, 14 with RVP, and 14 controls [AAI mode]) were evaluated. After continuous pacing algorithm, QRS duration, QT interval, QTc, JT interval, T-peak to T-end (Tpe), and Tpe/QT ratio were measured on electrocardiography at baseline and 1 week, 1 month, and 6 months postoperatively. We investigated VA occurrence and adverse events after implantation. Results At 6 months, QRS duration was significantly shorter in the HBP (121.6 +/- 15.6 ms) than in the RVP (150.1 +/- 14.9 ms) group. The QT intervals were lower in the HBP (424.0 +/- 40.9 ms) and control (405.9 +/- 23.0 ms) groups than in the RVP (453.0 +/- 40.2 ms) group. The Tpe and Tpe/QT ratios at 6 months differed significantly between the HBP and RVP groups (Tpe, 69.8 +/- 19.7 ms vs 87.4 +/- 11.9 ms and Tpe/QT, 0.16 +/- 0.03 vs 0.19 +/- 0.02, respectively). The Tpe and Tpe/QT ratios were similarly shortened in the HBP and control groups. VA occurred less frequently in the HBP (15%) and control (7.1%) groups than in the RVP (50%) group (p = 0.020). The non-RVP group showed significantly lower rates of VA and major adverse events than the RVP group. Patients with VA demonstrated significantly longer QRS duration, QT interval, Tpe, and Tpe/QT at 6 months than those without VA. Conclusion HBP showed better depolarization and repolarization stability than RVP.