Assessment of left ventricular activation conduction during left bundle branch area pacing in heart failure patients: A novel criterion to determine left bundle branch capture

Left bundle branch (LBB) area pacing (LBBAP) has become a cardiac resynchronization therapy (CRT) modality in patients with heart failure (HF) and LBB block (LBBB). LBB pacing (LBBP) and left ventricular (LV) septal myocardial pacing (LVSP) are the two pacing modalities of LBBAP(1 Chung M.K. Patton K.K. Lau C.P. et al. 2023 HRS/APHRS/LAHRS guideline on cardiac physiologic pacing for the avoidance and mitigation of heart failure. Heart Rhythm. 2023; S1547-5271 (02026-X) Google Scholar ). However, the electrophysiological differences between LBBP and LVSP and the methods to differentiate LBBP from LVSP in patients with HF and LBBB need investigations.