Acute hemodynamic benefit of multisite ventricular pacing after congenital heart surgery

Abstract

Background Cardiac dysfunction after congenital heart surgery is a major cause of morbidity and mortality. Cardiac resynchronization through multisite ventricular pacing (MSVP) improves cardiac index and ventricular function, and lowers systemic vascular resistance (SVR) in adults with heart failure and interventricular conduction delay. Methods The acute hemodynamic effects of MSVP after congenital heart surgery were assessed. Twenty-nine patients (aged 1 week to 17 years) with prolonged QRS interval had atrial and ventricular unipolar epicardial temporary pacing leads placed at surgery. Group 1 consisted of patients with a single ventricle (n = 14); group 2 included patients with two-ventricle anatomy (tetralogy of Fallot, ventricular septal defect) undergoing ventricular surgery (n = 10); and group 3 included patients with two-ventricle anatomy undergoing other cardiac surgery (n = 5). At a mean postoperative day 1 (range, 0 to 6), blood pressure, systemic and mixed venous oxygen saturations, electrocardiograms, and echocardiograms were obtained before and after 20 minutes of MSVP. Results The QRS duration decreased with MSVP in all patients (mean, 23%, p < 0.005). Systolic blood pressure improved in all patients (mean, 9.7%, p < 0.005). Cardiac index improved in 19 of 21 patients tested, with no change in 2 patients (mean, 15.1%, p = 0.0001). In 2 patients, MSVP facilitated weaning from cardiopulmonary bypass. Echocardiographic mitral or tricuspid valve inflow was not significantly different with MSVP. Conclusions Multisite ventricular pacing results in improved cardiac index and increased systolic blood pressure, and it can also facilitate weaning from cardiopulmonary bypass. Multisite ventricular pacing may be used as adjunct to standard postoperative treatment of cardiac dysfunction after congenital heart surgery.