Temporal change in right ventricular pacing ratio and its association with cardiac function and arrhythmia: A linear mixed-effects model analysis.

BACKGROUND

Right ventricular pacing (RVP) induces electrical and mechanical dyssynchrony, possibly influencing left ventricular (LV) dysfunction and heart failure (HF). However, the impact of temporal increases in the RVP ratio (RVP%) on LV remodeling and arrhythmia remains unclear.

OBJECTIVE

This study aimed to evaluate the association between longitudinal changes in RVP% and subsequent adverse LV remodeling and arrhythmia occurrence.

METHODS

We conducted a retrospective longitudinal cohort study of patients who underwent RVP implantation between May 2013 and December 2024. Patients with ≥6 months of follow-up and serial RVP% data were included. The annual RVP% change rate (slope, %/y) was estimated using linear regression; a slope of ≥10%/y was used to define those in the elevation group, whereas the stable group comprised those with a slope of <10%/y. Primary outcomes were changes in LV ejection fraction and LV end-diastolic dimension. Secondary outcomes included device-detected atrial fibrillation, ventricular tachyarrhythmia (ventricular tachycardia/ventricular fibrillation), and HF hospitalization.

RESULTS

Among 148 patients (median follow-up 1825 days), 37 (25%) were in the elevation group. RVP% increased significantly over time (interaction P < .001). LV ejection fraction declined faster (-3.33%/y vs -1.81%/y; P = .028), with LV end-diastolic dimension progressively enlarging (+1.19 mm/y vs -0.19 mm/y; P < .001). The elevation group showed higher ventricular tachycardia/ventricular fibrillation risk (hazard ratio 6.48; 95% confidence interval 3.44-12.2; P < .001), confirmed by joint modeling (P = .0002), with no association with atrial fibrillation (P = .33). Hospitalization for HF was more frequent (adjusted hazard ratio 3.41; 95% confidence interval 1.42-8.20; P = .006).

CONCLUSION

Progressive RVP% increase is independently associated with adverse LV remodeling and arrhythmic events, serving as a potential clinical risk marker.