Tauseef Akhtar

and 8 more

Background: Data related to electrophysiologic characteristics of atypical atrial flutter (AFL) following atrial fibrillation (AF) ablation and its prognostic value on repeat ablation success are limited. Methods: We studied consecutive patients undergoing a repeat LA ablation for either recurrent AF or atypical AFL, following 3 months after index AF ablation, between January 2012 and July 2019. The demographics, procedural data, complications, and 1-year arrhythmia-free survival rates were recorded for each subject after the first repeat ablation. Results: Of the total 336 included patients, 102 underwent a repeat ablation for atypical AFL and 234 for recurrent AF. The mean age was 63.7  10.7 years, and 72.6 % of patients were male. The atypical AFL cohort had significantly higher LA diameters (4.6 vs. 4.4 cm, p=0.04) and LA volume indices (LAVi; 85.1 vs. 75.4 ml/m2, p=0.03) compared to AF patients at repeat ablation. Atypical AFLs were roof-dependent in 35.6% and peri-mitral in 23.8% of cases. Major complications at repeat ablation occurred in 0.9 % of the total cohort. Arrhythmia-free survival at one year was significantly higher in the recurrent atypical AFL than the recurrent AF cohort (75.5 vs. 65.0 %, p=0.04). Conclusion: In our series, roof-dependent flutter is the most common form of atypical atrial flutter post AF ablation. Patients developing atypical AFL after index AF ablation have greater LA dimensions than patients with recurrent AF. The success rate of first repeat ablation is significantly higher among patients with recurrent atypical AFL compared to recurrent AF after index AF ablation.