Discussion of LBBP synchronization effects in HF patients with LBBB and comparison with BiV-CRT.

Left bundle branch block (LBBB) is common in heart failure patients, and could induce dyssynchrony of ventricular contraction, deterioration of cardiac function, and increased mortality. Cardiac resynchronization therapy (CRT) with biventricular pacing reduces ventricular dyssynchrony, heart failure hospitalization, and all-cause mortality in heart failure patients with LBBB. However, there are approximately 30% nonresponders and 10% of patients remain untreated owing to an unsuitable coronary sinus vein. His bundle pacing (HBP) is a more physiological pacing modality which has showed inspiring outcomes in heart failure patients with LBBB, but is limited by implantation challenges, lower success rates, and high pacing capture threshold. Recently, left bundle branch pacing (LBBP), defined as the capture of left bundle branch via transventricular septal approach, has emerged as a newly physiological pacing modality, which is implanted slightly distal to the His bundle. Early clinical studies have demonstrated the procedural feasibility of LBBP with rare complications and high success rate. Recent studies have indicated its potential to be an alternative for CRT. Synchronization effect and the current status of LBBP in the field of CRT are summarized in this paper.