Left Bundle Branch Area Pacing Versus Right Ventricular Pacing in Bradycardia

Introduction: Right ventricular pacing (RVP) has been the standard approach for patients with bradycardia requiring permanent pacing. However, RVP is linked with increased mortality risk and detrimental ventricular effects causing dyssynchronous ventricular activation, contributing to left ventricular dysfunction and pacing-induced cardiomyopathy (PICM). Left bundle branch area pacing (LBBAP) restores near-normal ventricular conduction preserving electrical synchrony and mechanical function. The objective of this study is to compare the electrical, mechanical, and clinical outcomes of LBBAP versus RVP in adult bradycardia patients. Methods: A systematic literature search was conducted across medical databases to identify studies comparing LBBAP to conventional RVP in patients with bradycardia undergoing pacemaker implantation. Pooled effect sizes were estimated using random-effects models.Statistical analysis was conducted via R Software. Subgroup and Sensitivity analyses using leave-one-out methodology were performed. Publication bias was assessed via Egger’s test. Results: Six studies enrolling 2,961 patients (LBBAP n = 1,472; RVP n = 1,489) were included. LBBAP was associated with significantly shorter post-implant QRS duration compared with RVP (MD –28.2 ms, 95% CI –34.6 to –21.8 ms; p < 0.001; I 2 = 76.6%). On subgroup analysis, larger (≥300) and prospective studies produced greater effect estimates with markedly decreased heterogeneity (MD -33.7, 95% CI -37.5 to -29.9, I 2 = 22%) and (MD -34.8, 95% CI -38.9 to -30.7, I 2 = 18%), respectively. LBBAP also showed significantly decreased lead impedance (MD -10.0, 95% CI -18.76 to -1.24, I 2 = 0%, p = 0.03) and LV-End Diastolic Diameter (MD -2.28, 95% CI -2.84 to -1.72, I 2 = 0%, p < 0.001). For clinical events, LBBAP demonstrated a 43% relative risk reduction in composite adverse outcomes (RR 0.57, 95% CI 0.38-0.86; p = 0.007; NNT ≈15). Safety event rates were low and numerically comparable between groups (LBBAP ∼1.1% vs. RVP ∼1.4%). Egger’s test suggested no significant publication bias (p = 0.09). Conclusion: LBBAP provides superior electrical resynchronization with significantly fewer adverse clinical outcomes compared with conventional RVP. These findings support LBBAP as a preferred pacing strategy, particularly in patients at risk of PICM. High heterogeneity driven primarily by study design differences warrants cautious interpretation, and adequately powered randomized controlled trials are needed to confirm these benefits.