Abstract 8898: Biventricular Function is Impaired in RV Septal Pacing - A Prospective Study Using Myocardial Strain Imaging

Abstract

Introduction: Left ventricular (LV) dysfunction is observed after right ventricular (RV) pacing from both apical and septal positions. Hypothesis: The primary aim of this study was to assess the impact of RV mid-septal pacing upon RV function using the novel parameter of speckle-tracking derived RV global longitudinal strain (RVGLS), as well as the conventional parameters RV fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE) and tricuspid annular systolic velocity (RV S’). Secondary aims included assessing the impact on LV function and the correlation of pacing burden with echocardiographic parameters. Methods: Thirty-two consecutive patients (mean age 75 ± 10 years) with normal baseline LV and RV function requiring permanent pacemaker insertion were prospectively recruited at a tertiary hospital in Melbourne, Australia. 3 patients were excluded due to poor image quality. Echocardiography was performed prior to implantation, at 1-day, 1-month and 1-year post-implantation, with 29 patients completing follow-up. Results: Compared to 1-day post-implantation, at 1-year a significant decline was noted in mean RV S’ (15.1 to 12.2cm/s), TAPSE (24.2 to 21.9mm), RV GLS (-24.8 to -21.8%), LVEF (66.0 to 57.9%), LV GLS (-19.9 to 17.0), all p <0.01. There was no change in RV FAC (49.1 to 46.9%). Fourteen patients (44%) required a high proportion of ventricular pacing, defined as ≥10% at 1 year. These patients had a greater deterioration in RVGLS (5.0 vs 1.0%) and LVGLS (4.6 vs 0.68%), p <0.05. Changes in RV S’ (3.1 vs 2.7cm/s), TAPSE (1.5 vs 3.1mm), RV FAC (1.9 vs 5.64%) and LVEF (9.5 vs 5.6%) were not significantly different from those in patients with <10% ventricular pacing. Conclusions: RV and LV systolic function declined in all patients after 1 year of RV septal pacing. Further, patients with a high burden of ventricular pacing had a larger deterioration in RVGLS and LVGLS. Myocardial strain may be more useful than conventional echo parameters in detecting RV and LV dysfunction associated with RV septal pacing.