Implementation of a Protocol Utilizing Adaptive CRT in a Normal AV Conduction, CRT Non-Response Population at Generator Replacement

IMPROVE RESPONSE is a physician initiated research study. It is a prospective, non-randomized, multi-center, post-market, U.S. Cardiac Resynchronization Therapy (CRT) in heart failure (HF) observational study. The purpose of this clinical study is to test the hypothesis that market-released CRT devices, which contain the AdaptivCRT (aCRT) algorithm have an incremental benefit in improving CRT response in a chronic CRT non responder population with left bundle branch block (LBBB) and normal atrio-ventricular (AV) condition compared to CRT devices with traditional biventricular pacing delivery methods at generator replacement.