Complete electrical reverse remodeling of native conduction after resynchronization therapies.

Area of Science:

• Cardiology
• Electrophysiology
• Medical Devices

Background:

• Cardiac resynchronization therapy (CRT) improves outcomes.
• Electrical reverse remodeling (ER) of native conduction is linked to better CRT results.
• Complete electrical reverse remodeling (CERR) is a specific ER outcome.

Purpose of the Study:

• To characterize patients with CERR after CRT.
• To investigate the time course of CERR.
• To determine the long-term outcomes of CERR.

Main Methods:

• CRT candidates received biventricular, His bundle, or left bundle branch pacing.
• CERR was defined by a post-implantation QRS duration ≤120 ms.
• Patient characteristics, QRS duration, and clinical outcomes were analyzed.

Main Results:

• 12 out of 322 patients achieved CERR, all with non-ischemic cardiomyopathy and LBBB.
• Mean QRS duration decreased from 175.0 ms to 110.8 ms.
• CERR occurred between days and 18 months post-implantation; 91.7% showed echocardiographic super-response.

Conclusions:

• CERR patients responded well to various CRT strategies.
• The timing of CERR and super-response varied significantly.
• Native conduction variability suggests electrical disorder-related cardiomyopathy mechanisms.