Late dislodgement of left bundle branch pacing lead and failure of left ventricle capture management algorithm.

A 74-year-old man with nonischemic cardiomyopathy, LV ejection fraction (LVEF) of 20 % and left bundle branch block (LBBB) underwent successful cardiac resynchronization therapy defibrillator (CRT-D) implantation utilizing LBBP lead in the LV port. Despite normalization of LVEF at 6 months, patient presented with late lead dislodgment at 10 months post-implant and decline in LV function. LV capture management algorithm was inactive due to sensing of conducted beat as ventricular fibrillation sensed event. Removal and replacement of LBBP lead resulted in recovery of LV function.