Ventricular remodeling during long-term right ventricular pacing following His bundle ablation

Area of Science:

• Cardiology
• Electrophysiology
• Cardiac Imaging

Background:

• Atrial arrhythmias often necessitate interventions like His bundle ablation (HBA) with pacemaker implantation (HBA-PI).
• Right ventricular (RV) pacing is a common consequence of HBA, raising concerns about potential ventricular remodeling.

Purpose of the Study:

• To evaluate ventricular remodeling during long-term RV pacing following HBA in patients with atrial arrhythmias.
• To identify factors influencing RV pacing-induced ventricular changes.

Main Methods:

• Retrospective analysis of echocardiographic data from 45 patients undergoing HBA-PI.
• Echocardiography performed 1 year pre-HBA-PI and up to 7 years post-HBA-PI.
• Patients categorized into two groups based on baseline left ventricular end-diastolic diameter (LVEDD).

Main Results:

• An inverse relationship observed between baseline LVEDD and relative LVEDD increase during RV pacing.
• Patients with initially normal LVEDD (Group I) showed significant increases in LVEDD, LV dimensions, LV weight, and left atrial diameter after long-term RV pacing.
• Group I also exhibited decreased LV ejection fraction, LV fractional shortening, and increased mitral regurgitation.
• No significant changes were noted in patients with initially enlarged LVEDD (Group II).

Conclusions:

• Long-term RV pacing after HBA adversely affects left ventricular structure and function in patients with initially normal LV dimensions and function.
• Baseline LV dimensions are a critical factor in determining susceptibility to RV pacing-induced remodeling.