Left bundle branch area pacing is associated with higher cardiac baroreflex sensitivity during orthostatic challenge

Cardiac baroreflex function during orthostatic challenge remains poorly characterized in chronically paced patients. While conventional right ventricular (RV) pacing induces non-physiological activation, left bundle branch area pacing (LBBAP) restores near-normal ventricular activation. We compared their effects on cardiac baroreflex sensitivity (BRS) during standardized orthostatic challenge. We prospectively studied 100 patients with atrioventricular block—50 LBBAP, 50 RV pacing (25 apical pacing, 25 septal pacing). At 3 months, all underwent a standardized protocol (supine–tilt–recovery; 45°). Continuous beat-to-beat hemodynamics were recorded, and BRS was assessed using the sequence method alongside baroreflex effectiveness index (BEI). LBBAP was independently associated with significantly higher BRS compared to RV pacing across all phases (β = + 6.8 ms/mmHg; 95% CI + 3.9 to + 9.7; p < 0.001). At rest, BRS was significantly higher in LBBAP versus RV pacing (15.37 ± 6.05 vs. 8.19 ± 4.35 ms/mmHg). Both groups showed tilt-induced BRS reduction; however, during head-up tilt, BEI decreased in the RV pacing group ( p = 0.018), while no significant within-group change was observed in the LBBAP group. A significant inverse ΔHR–ΔBRS association was observed only in LBBAP (ρ = − 0.43; p = 0.0016). No between-group differences in blood pressure or heart rate were observed. LBBAP is associated with higher baroreflex gain and preserved chronotropic–baroreflex coupling compared with RV pacing, despite comparable systemic hemodynamic responses. These findings suggest an association between ventricular activation pattern and autonomic cardiovascular regulation. The potential implications for arrhythmic risk and long-term outcomes require confirmation in dedicated outcome studies.