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 < .0001) while the LV mechanical synchrony during LBBP pacing mode was similar to that of native-conduction mode (SDI, 3.14 ± 2.49 vs 2.70 ± 1.68, P = 0.129; Tsd-12-LV, 26.43 ± 15.55 vs 25.61 ± 16.07, P = .671) in the LBBP group. The LV synchrony in the LBBP group was superior to the RVSP group significantly. No significant differences in SV (64.08 ± 16.97 mL vs 65.45 ± 18.68 mL, P = .241) or the degree of atrioventricular valvular regurgitation were noted between LBBP capture and native-conduction modes. Conclusion: LBBP could preserve satisfactory LV synchrony and result in favorable hemodynamic effects. K E Y W O R D S cardiac mechanical synchrony, echocardiography, hemodynamic effects, left bundle branch pacing, physiological pacing, right ventricular septum pacing, sick sinus syndrome ---

Feasibility and stability of left bundle branch pacing in patients after prosthetic valve implantation

“…Some studies also confirmed the short‐term and medium‐term feasibility and stability of LBBP 27‐29 . It has been proved that reduction in electric dyssynchrony was reflected by the shorter QRS duration and stim‐LVAT during LBBP, which could translate to acute hemodynamic effects compared with RVP 7,27 . In our present study, majority of patients with PVs succeeded in LBBP and presented a narrow pQRSD and short stim‐LVAT.…”

“…Zhang et al confirmed the effectiveness of LBBP in heart failure patients complicated with LBBB 26 . In our previous study, we convinced that LBBP may bring about better electrical and mechanical synchrony compared with RVP 7 . Some studies also confirmed the short‐term and medium‐term feasibility and stability of LBBP 27‐29 .…”

The long‐term therapeutic effects of His‐Purkinje system pacing on bradycardia and cardiac conduction dysfunction compared with right ventricular pacing: A systematic review and meta‐analysis

“…Moreover, LBBP is a relatively novel physiological pacing strategy, and the effects of LBBP on cardiac synchrony remain vague 23,24 . LBBP could either directly capture LBB, LBB together with nearby myocardium, or nearby myocardium, and then propagates to LBB, eventually activating the whole left ventricle.…”

Erratum

“…When the article 1 was first published online, the data of baseline QRSd in Table 1 was not updated.…”