Overview
Left main stem bundle branch block refers to a conduction abnormality within the heart's electrical system. Management strategies focus on restoring physiological ventricular activation, particularly in patients with severe heart failure and reduced ejection fraction, or bradyarrhythmia 12.Management
For patients with severe heart failure, left branch block, and an ejection fraction <35%, cardiac resynchronization therapy (CRT) is a treatment option 1.
His bundle pacing (HBP) demonstrated superior outcomes compared to biventricular pacing (BiV) in heart failure patients, including greater QRS shortening, increased left ventricular ejection fraction (LVEF), lower left ventricular end-systolic volume (LVESV), and improved New York Heart Association (NYHA) functional class 1.
Left bundle branch area pacing (LBBaP) is a potential alternative to HBP for maintaining a physiologic ventricular activation pattern 2.
LBBaP offers several advantages over HBP, including increased R wave amplitudes, lowered capture thresholds, shortened procedure times, shortened fluoroscopic durations, and increased success rates 2.
HBP can have disadvantages such as difficult lead implantation, reduced R wave amplitudes, and high and unstable pacing thresholds 2.Key Recommendations
For patients with severe heart failure, left branch block, and an ejection fraction <35%, cardiac resynchronization therapy (CRT) should be considered 1. (Evidence: Strong)
His bundle pacing (HBP) is more effective than biventricular pacing (BiV) for CRT, leading to greater QRS shortening, increased left ventricular ejection fraction, reduced left ventricular end-systolic volume, and improved NYHA functional class 1. (Evidence: Strong)
Left bundle branch area pacing (LBBaP) is a potential alternative to HBP, offering advantages such as easier implantation (shorter procedure and fluoroscopy times), improved sensing (increased R wave amplitudes), and more stable pacing (lower capture thresholds) 2. (Evidence: Moderate)References
1 da Silva Menezes Junior A, Melo MGZ, Barreto LP. Meta-analysis of clinical outcomes in cardiac resynchronisation therapy: his bundle pacing vs biventricular pacing. Expert review of medical devices 2023. link
2 Yuan Z, Cheng L, Wu Y. Meta-Analysis Comparing Safety and Efficacy of Left Bundle Branch Area Pacing Versus His Bundle Pacing. The American journal of cardiology 2022. link