Evaluation of cardiac synchrony in left bundle branch pacing: Insights from echocardiographic research

Abstract

Aim: The aim of this study is to assess if left bundle branch pacing (LBBP) can preserve physiological cardiac synchrony and deliver favorable hemodynamic effects. Methods: Consecutive patients undergoing dual chamber pacemaker implantation for sick sinus syndrome (SSS) and a normal cardiac function with a narrow QRS complex were recruited for the study. Electrocardiogram and echocardiographic examinations were performed during ventricular pacing-on and native-conduction modes. The QRS duration (QRSd), systolic dyssynchrony index (SDI), and the standard deviation of time-to-peak contraction velocity in left ventricular (LV) 12 segments (Tsd-12-LV) were measured to evaluate LV synchrony. The stroke volume (SV) and the degree of atrioventricular valvular regurgitation were also assessed. Results: A total of 40 patients underwent LBBP, while another 38 patients underwent right ventricular septum pacing (RVSP) as control group. Baseline characteristics were similar between the two groups. With LBBP, the paced QRSd was slightly wider than the intrinsic QRSd (101.03 ± 8.79 ms vs 91.06 ± 14.17 ms, P