P5682Cardiac resynchronization therapy with a single left ventricular septal pacing electrode: acute hemodynamic and electrophysiological effects

Abstract

Abstract Background Cardiac resynchronization therapy (CRT) is usually performed with a right (RV) and left ventricular (LV) lead. In a previous patient study, pacing the interventricular septum permanently on the LV endocardial side (LV septum) proved feasible in patients with sinus node dysfunction. Objective To investigate the effects of LV septal pacing as compared to conventional biventricular (BiV) pacing with respect to acute hemodynamic and electrophysiological effects in CRT indicated heart failure patients. Methods Temporary LV septal pacing (transarterial approach) and pacing in the conventional BiV mode using the implanted leads was performed in 26 patients (QRS duration 163±17 ms, 23 left bundle branch block patients) undergoing CRT implantation. Acute hemodynamic response (relative to baseline AAI pacing) was assessed by LVdP/dtmax. Multi-electrode body-surface mapping, what has been used previously to characterize electrical dyssynchrony in CRT patients, was evaluated using the standard deviation of activation times (SDAT) (figure, right panel). Results LV septal pacing resulted in a significant LV dP/dtmax increase, that was comparable to conventional BiV pacing (figure, left panel). Combined RV and LV septal pacing did not provide an additional increase. LV septal pacing resulted in a significantly larger reduction in SDAT than RV plus LV septal pacing and conventional BiV pacing (figure, middle panel). Conclusions LV septal pacing results in acute hemodynamic improvement and electrical resynchronization that is at least as good as conventional BiV pacing. These results suggest that LV septal pacing with a single ventricular lead may serve as an alternative to conventional BiV pacing for cardiac resynchronization. Acknowledgement/Funding Medtronic is a subsidising party.