Short-Term Hemodynamic and Electrophysiological Effects of Cardiac Resynchronization by Left Ventricular Septal Pacing

Abstract Background Cardiac resynchronization therapy (CRT) is usually performed by biventricular (BiV) pacing. Previously, feasibility of transvenous implantation of a lead at the left ventricular (LV) endocardial side of the interventricular septum, referred to as LV septal (LVs) pacing, was demonstrated. Objectives The authors sought to compare the acute electrophysiological and hemodynamic effects of LVs with BiV and His bundle (HB) pacing in CRT patients. Methods Temporary LVs pacing (transaortic approach) alone or in combination with right ventricular (RV) (LVs+RV), BiV, and HB pacing was performed in 27 patients undergoing CRT implantation. Electrophysiological changes were assessed using electrocardiography (QRS duration), vectorcardiography (QRS area), and multielectrode body surface mapping (standard deviation of activation times [SDAT]). Hemodynamic changes were assessed as the first derivative of LV pressure (LVdP/dtmax). Results As compared with baseline, LVs pacing resulted in a larger reduction in QRS area (to 73 ± 22 μVs) and SDAT (to 26 ± 7 ms) than BiV (to 93 ± 26 μVs and 31 ± 7 ms; both p  Conclusions LVs pacing provides short-term hemodynamic improvement and electrical resynchronization that is at least as good as during BiV and possibly HB pacing. These results indicate that LVs pacing may serve as a valuable alternative for CRT.