Chen, Shiquan

AbstractBackgroundHis bundle pacing (HBP) is a physiological pacing strategy to preserve the electrical synchrony of ventricular conduction and left ventricular (LV) function. Left bundle branch pacing (LBBP) has emerged as an alternative physiological pacing technique.ObjectiveTo evaluate cardiac electrical and mechanical synchrony comparing LBBP and HBP in patients with permanent atrial fibrillation (AF).MethodsConsecutive patients with symptomatic bradycardia and AF were enrolled from January to June of 2019. The cardiac electrical and mechanical synchrony in different pacing mode were evaluated at baseline and after implantation.ResultsBoth HBP and LBBP were performed in 20 patients. LBBP significantly widened the QRS duration compared with the intrinsic conduction (113.2 ± 14.5 vs. 96.5 ± 16.2 ms; p = .01), while HBP did not (104.5 ± 22.3 vs. 96.5 ± 16.2 ms; p = .12). Both LBBP and HBP patients had similar LV myocardial strain measurements for the mechanical synchrony evaluation without significant change compared with baseline. There was no significant difference in right ventricular synchrony measurement between LBBP and HBP. Compared to HBP, LBBP had less interventricular synchrony (IMVD, 14.7 ± 9.2 vs. 3.1 ± 12.7 ms, p < .01; Ts‐LV‐RV, 37.9 ± 10.7 vs. 18.5 ± 10.8 ms, p < .001).ConclusionsAlthough LBBP's a physiological pacing mode can achieve a similar cardiac electrical and mechanical synchronization when compared to HBP, LBBP results in modest delay in RV activation, and the clinical implication remains to be studied.