Progressive and Simultaneous Right and Left Atrial Remodeling Uncovered by a Comprehensive Magnetic Resonance...

Area of Science:

• Cardiology
• Cardiac Imaging
• Electrophysiology

Background:

• Left atrial remodeling is a known factor in atrial fibrillation (AF) arrhythmogenesis.
• The role of right atrial (RA) structural remodeling in AF and its prognostic implications post-ablation are not well understood.

Purpose of the Study:

• To characterize RA structural remodeling in patients with AF.
• To identify RA parameters that predict AF recurrence after ablation.

Main Methods:

• Cardiac magnetic resonance imaging (3.0 T late gadolinium enhancement) was used in 109 individuals (9 healthy, 100 with AF).
• Quantified RA and left atrial (LA) volume, surface, sphericity, and fibrosis burden.
• Assessed AF recurrence post-ablation through systematic follow-up.

Main Results:

• Progressive RA dilation and increased sphericity were observed with increasing AF severity.
• RA volume and shape were influenced by tricuspid regurgitation, while RA fibrosis was linked to diabetes.
• Right atrial sphericity, but not other RA or LA parameters, significantly predicted AF recurrence post-ablation (HR 1.12).

Conclusions:

• Atrial fibrillation progression is associated with parallel structural remodeling in both the right and left atria.
• Right atrial sphericity emerges as a significant independent predictor of AF recurrence following ablation.