Absence of left bundle branch block and blood urea nitrogen predict improvement in left ventricular ejection fraction in patients with cardiomyopathy and wearable cardioverter defibrillators.

Objective: To identify predictors of left ventricular ejection fraction (LVEF) improvement in patients with newly detected cardiomyopathy using wearable cardioverter defibrillators (WCDs).

Background: WCDs are useful in preventing sudden cardiac death in patients with reduced LVEF <35% while awaiting implantable cardioverter defibrillator (ICD) placement. In many patients, LVEF improves and an ICD is not indicated.