Abstract
Dilated cardiomyopathy (DCM) with severe mitral regurgitation (MR) and left bundle branch block (LBBB) typically indicates cardiac resynchronization therapy (CRT). However, device-related complications can limit CRT's applicability in some patients. A 77-year-old woman with DCM, severe MR, and LBBB underwent mitral valve transcatheter edge-to-edge repair (M-TEER) because of high risk for CRT-related complications. Post-procedure, she showed marked improvement in symptoms, left ventricular function, and QRS duration. This case highlights M-TEER as a potential initial strategy in selected patients with DCM, severe MR, and LBBB when CRT is high risk. The unexpected reduction in QRS duration following M-TEER warrants further investigation. M-TEER may be considered in DCM patients with severe MR and LBBB for whom CRT poses significant challenges. This approach could lead to both mechanical and electrical reverse remodeling in some cases.