Electrogram Morphology Recurrence for Mapping Persistent Atrial Fibrillation: Initial vs Redo Catheter Ablation.

Area of Science:

• Cardiology
• Electrophysiology
• Medical Imaging

Background:

• Persistent atrial fibrillation (AF) ablation requires precise identification of arrhythmogenic drivers.
• Electrogram (EGM) morphology recurrence (EMR) mapping quantifies activation consistency, expected to be high near AF drivers.

Purpose of the Study:

• To compare EMR characteristics in the left atrium (LA) and right atrium (RA).
• To evaluate EMR in patients undergoing first-time versus repeat ablation for persistent AF.

Main Methods:

• Multisite LA/RA mapping was performed in 42 patients (32 first ablation, 10 redo ablation).
• EGM signals were cross-correlated to identify the most recurrent morphology, its frequency (Rec%), and recurrence cycle length (CL_R).

Main Results:

• Minimum CL_R was shorter in the LA compared to the RA (P=0.0005) in first-time ablation patients.
• The shortest CL_R was located in the LA in 84% of first-time ablation patients versus 50% in redo cases (P=0.04).
• Pulmonary veins (PVs) were identified as the shortest CL_R site in 59% of initial ablation patients.

Conclusions:

• EMR mapping effectively identifies pulmonary veins as critical sites for AF maintenance in a majority of initial ablation patients.
• Most atrial sites exhibit low recurrence, suggesting they are not primary drivers of AF.
• EMR offers a novel, robust method for assessing activation consistency and directionality in the atria.