Electrical Resynchronization

Abstract

BACKGROUND: Many patients with congenital heart disease develop right ventricular (RV) failure due to anatomy and prior therapy. RV problems may include right bundle-branch block (RBBB), volume loading, and chamber enlargement. Because the failing RV may have regional dyskinesis, we hypothesized that resynchronization therapy might augment its performance. METHODS AND RESULTS: We studied 7 patients with RV dysfunction and RBBB, using a predefined pacing protocol. QRS duration, cardiac index (CI), and RV dP/dt were measured in 4 different pacing states. Atrioventricular pacing improved CI and RV dP/dtmax and decreased QRS duration as compared with atrial pacing or sinus rhythm. CONCLUSIONS: Atrioventricular pacing in patients with RBBB and RV dysfunction augments RV and systemic performance. RV resynchronization is a promising novel therapy for patients with RV failure.