Right Ventricular Pacing Burden-Dependent Biventricular Remodeling in Patients With Preserved Left Ventricular...

To assess right ventricular (RV) systolic trajectories across right ventricular pacing (RVP) burdens and their relationship with left ventricular (LV) remodeling in patients with preserved baseline LV ejection fraction (LVEF).

This prospective study included 200 patients undergoing dual-chamber pacemaker implantation with an apical RV lead. Clinical, electrocardiographic, device, and echocardiographic assessments were performed at baseline, three months, and 12 months. Patients were grouped by RVP burden: 0%-3% (n = 43), 70%-79% (n = 51), or ≥80% (n = 106). RV global longitudinal strain (RVGLS), RV fractional area change (RVFAC), and tricuspid annular plane systolic excursion (TAPSE) were evaluated using adjusted linear mixed-effects models. Continuous RVP associations and concurrent RV-LV changes were examined.

Among 200 patients (median age, 79 years), adjusted mixed-effects models demonstrated significantly different longitudinal trajectories across RVP groups for RVGLS (Holm-adjusted p = 0.0096) and TAPSE (Holm-adjusted p = 0.050), but not for RVFAC (Holm-adjusted p = 0.252). RVGLS and TAPSE deteriorated with high RVP while remaining comparatively stable with minimal pacing. Within the 70%-100% range, each 10% higher RVP burden was associated with an additional TAPSE reduction of 0.305 at 3-months (95%CI, 0.084, 0.527; p = 0.007) and 0.401 mm at 12-months (95%CI, 0.179, 0.622 mm; p < 0.001). The overall continuous time-by-RVP interaction was significant for TAPSE (Holm-adjusted p = 0.0035), but not for RVGLS or RVFAC. Worsening LVGLS was associated with deterioration in all RV indices at both assessments (FDR-adjusted p ≤ 0.0017), while increasing LV end-systolic volume was associated with all RV indices at 12-months (all FDR-adjusted p < 0.001).

Substantial RVP was associated with statistically detectable changes in RV indices. Within the high-pacing range, greater RVP burden was associated with a greater longitudinal decline in TAPSE. Concurrent RV-LV changes were also present, although their clinical significance requires further investigation.