Reverse Left Ventricular Remodeling Reversed Left Bundle Branch Block: A Case Report

Abstract

Left bundle branch block (LBBB) is frequently associated with cardiomyopathy and is generally considered irreversible,often prompting cardiac resynchronization therapy. However, emerging evidence suggests that optimal medical therapymay lead to reverse remodeling and resolution of LBBB. A 60-year-old female with heart failure presented with severeleft ventricular (LV) dysfunction (ejection fraction 25%) and LBBB. Coronary angiography was normal. Cardiacmagnetic resonance showed no fibrosis, and genetic testing was unremarkable. Guideline-directed medical therapywas initiated. Over 9 months, serial evaluations demonstrated progressive improvement in LV volumes and systolicfunction. Notably, LBBB resolved spontaneously, with a normalization of QRS duration. This case illustrates thatreverse LV remodeling with optimal medical therapy may be accompanied by resolution of LBBB in non-ischemiccardiomyopathy. These findings highlight the dynamic relationship between myocardial recovery and electricalconduction and may have implications for the timing of device therapy.