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

BACKGROUND Electrogram (EGM) morphology recurrence (EMR) mapping of persistent atrial fibrillation (AF) quantifies consistency of activation and is expected to be high and rapid near AF drivers. OBJECTIVES The purpose of this study was to compare EMR in left atria (LA) and right atria (RA) in patients undergoing first vs redo ablation for persistent AF. METHODS Multisite LA/RA mapping (LA: 281 +/- 176 sites/patient; RA: 239 +/- 166 sites/patient) before persistent AF ablation was performed in 42 patients (30 males, age 63 +/- 9 years) undergoing first (Group 1, n = 32) or redo ablation (Group 2, n = 10). After cross-correlation of each automatically detected EGM with every other EGM per recording, the most recurrent electrogram morphology was identified and its frequency (Rec%) and recurrence cycle length (CLR) were computed. RESULTS In Groups 1 and 2, minimum CLR was 172.8 +/- 26.0 milliseconds (LA: 178.2 +/- 37.6 milliseconds, RA: 204.4 +/- 34.0 milliseconds, P = 0.0005) and 186.5 +/- 28.3 milliseconds (LA: 196.1 +/- 38.1 milliseconds vs RA: 199.0 +/- 30.2 milliseconds, P = 0.75), with Rec% 94.7% +/- 10% and 93.8% +/- 9.2%. Group 2 minimum CLR was not different from Group 1 (P = 0.20). Shortest CLR was in the LA in 84% of Group 1 and 50% of Group 2 patients (P = 0.04). Only 1 of 10 patients in Group 2 had the shortest CLR in the pulmonary veins (PVs) compared with 19 of 32 in Group 1 (P = 0.01). Most sites (77.6%) had Rec% <50%. CONCLUSIONS EMR identified the shortest CLR sites in the PVs in 59% of patients undergoing initial persistent AF ablation, consistent with reported success rates of similar to 50% for PV isolation. The majority of sites have low recurrence and may reflect bystander sites not critical for maintaining AF. EMR provides a robust new method for quantifying consistency and rapidity of activation direction at multiple atrial sites. (c) 2023 Published by Elsevier on behalf of the American College of Cardiology Foundation.

Automated summary

This study compared the recurrence of electrogram morphology in the left and right atria in patients undergoing initial and repeat ablation for persistent atrial fibrillation. The results showed that electrogram morphology recurrence was mainly observed in the left atrium, and the shortest cycle length recurrence occurred during the initial ablation process. Most sites had low recurrence, suggesting that they may not be critical for maintaining atrial fibrillation.