Pacing therapies for heart failure

Congestive heart failure due to left ventricular systolic dysfunction is frequently accompanied by derangements in the cardiac conduction system. These electrical abnormalities can have a negative impact on cardiac output. As a result, pacemakers have been considered as a potential treatment for congestive heart failure when conduction system disease is present. Early reports of dual chamber pacing with a short atrioventricular delay suggested hemodynamic improvements in congestive heart failure patients; however, subsequent randomized trials failed to confirm these findings. Mechanical asynchrony resulting from left bundle branch block or intraventricular conduction delay impairs cardiac output. Biventricular pacing can resynchronize ventricular contraction in patients with left bundle branch block or intraventricular conduction delay and improve systolic function. In randomized clinical trials, patients with conduction delay and severe congestive heart failure despite maximal medical therapy have been shown to derive significant functional benefits from biventricular pacing. Biventricular pacing has the potential for wide application in congestive heart failure treatment.