Abstract 11980: Reversibility of Deleterious Effect of Right Ventricular Apical Pacing in PACE Study Patients After Crossing Over to Biventricular Pacing
INTRODUCTION: Pacing to Avoid Cardiac Enlargement (PACE) trial is a prospective, double-blinded, randomized, multicenter study that reported the superiority of biventricular (BiV) pacing to right ventricular apical (RVA) pacing in prevention of left ventricular (LV) adverse remodeling and deterioration of systolic function at 1-year in patients with standard pacemaker indication and normal LV ejection fraction. In the current analysis, we reported the results of patient crossing over from to BiV pacing after long term RVA pacing.
Methods: Forty-one patients (age of 68±12 years, 18 males) randomized to RVA pacing in PACE study was crossed over to BiV pacing after 57+/-14 months. Serial echocardiography with tissue Doppler imaging was performed before pacemaker implantation and 1 day before and 1-month, 6-month after switching to BiV pacing. Systolic dyssynchrony was assessed with standard deviation of time-to-peak systolic velocity (Ts-SD) using a12-segment model. LV volumes and ejection fraction were assessed with real-time three-dimensional echocardiography.
RESULTS: After long term RVA pacing LV systolic function and LV volume worsen and systolic dyssynchrony increased when compared to baseline. Improvement of the deleterious change was observed as soon as 1 month after switching to BiV pacing. In addition, LV ejection fraction and volume continued to be improved at 6 month and systolic dyssynchrony remained unchanged when compared to the corresponding parameters at 1 month. (Table)
CONCLUSIONS: The deleterious effect on LV function and LV remodeling of long-term RVA pacing is reversible by switching to BiV pacing.
- © 2013 by American Heart Association, Inc.