Comparison of Left Ventricular Global Ejection Fraction Using Three Dimensional Echocardiography in Septal Versus Apical Right Ventricular Pacing

Introduction: Right ventricular pacing is critical for managing bradyarrhythmia but can impair left ventricular function due to dyssynchrony. This study examines the impact of septal versus apical pacing on left ventricular ejection fraction (LVEF) using three-dimensional echocardiography, aiming to determine which approach better preserves cardiac function by maintaining more physiologic ventricular activation. Material and methods: This randomized historical‑control study included 60 patients undergoing permanent pacemaker implantation at Shahid Madani Hospital between 2011 and 2013. Patients were assigned to septal or apical right ventricular pacing. Three‑dimensional echocardiography was used to compare left ventricular volumes and ejection fraction, with blinded assessment and standard statistical analyses to evaluate functional differences between pacing strategies. Results: Patients with septal right ventricular pacing demonstrated preserved conventional and three‑dimensional ejection fraction with no significant deviation from normal values (P>0.05). Compared with apical pacing, septal pacing was associated with significantly higher conventional and 3D ejection fraction and less impaired septal longitudinal strain, with a clear intergroup difference in SPSS‑Sep.A (P=0.001). Conclusion: This study demonstrates that right ventricular septal pacing is associated with more favorable left ventricular systolic performance compared with apical pacing when assessed using both conventional and three‑dimensional echocardiography.