Preservation of synchronicity and function by left bundle branch area pacing for atrioventricular block: a randomized controlled trial

Abstract Background Novel left bundle branch area pacing (LBBAP) was suggested to provide more physiological pacing than right ventricular pacing with a shorter paced QRS duration (QRSd) and left ventricular (LV) activation time. However, evidence on its clinical superiority from randomized controlled trials is lacking. Purpose This study aimed to evaluate the effects of LBBAP on LV systolic synchrony and function in patients with atrioventricular block (AVB), in comparison to right septal ventricular pacing (RVSP). Methods The study randomized 80 patients (40 males, 63±9 years) to receive either LBBAP (n=38) or RVSP (n=42). In addition to QRSd measured on surface electrocardiogram, peak strain dispersion percentage (PSD%), global longitudinal strain (GLS) and myocardial work (MW) were assessed using speckle-tracking echocardiography before implantation, at 3-day and 6-month follow-up. Results Baseline characteristics were similar between the two groups. Both displayed an acute exacerbation of LV synchronicity and function at 3-day follow up, but a differential change afterwards. At 6 months, the LBBAP group demonstrated significant recovery and the RVSP group did not in terms of QRSd, PSD%, GLS, and MW including global work index (GWI), global constructive work (GCW), global wasted work (GWW), and global work efficiency (GWE). At 6-month follow-up, the LBBAP group showed a superior performance in LV synchronicity, GLS, and MW compared to the RVSP group (all p0.05) (Figure 1 and Table 1). Conclusions LBBAP better preserves LV synchronicity and function compared to RVSP in patients with AVB that makes it a preferable treatment option.Electrical and mechanical synchrony Comparison of LV Function