Eurasian Journal of Chemical, Medicinal and Petroleum Research

Abstract 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.

Abstract Introduction: Right ventricular pacing can profoundly influence left ventricular mechanics, particularly when non‑physiological activation patterns induce mechanical dyssynchrony and impaired myocardial deformation. Global peak systolic strain is a sensitive marker for detecting pacing‑related alterations in ventricular function. This study aimed to evaluate and compare global peak systolic strain in patients undergoing right ventricular apical versus septal pacing to determine the pacing site associated with more preserved myocardial mechanics.

Material and methods: This randomized historical control study included 60 patients undergoing permanent right ventricular pacing at a tertiary cardiac center. Participants were equally assigned to apical or septal pacing. Standardized echocardiography with speckle tracking analysis was performed to quantify global peak systolic strain, and outcomes were compared using appropriate statistical methods under blinded assessment and ethical approval.

Results: Right ventricular pacing was associated with significant impairment of left ventricular myocardial deformation. Global longitudinal strain showed a stepwise reduction from normal subjects to septal pacing and was most severely attenuated with apical pacing (p < 0.001). Inferior and mid‑inferior segmental strain was preserved with septal pacing but significantly reduced with apical pacing compared with both normal and septal groups (p ≤ 0.01).

Conclusion: This study demonstrates that the site of right ventricular pacing is a critical determinant of left ventricular mechanical performance. Although septal pacing does not fully replicate physiological ventricular activation, it is associated with relatively preserved global and regional myocardial deformation and reduced mechanical heterogeneity compared with apical pacing.