Background: Atypical Atrial Flutter (AAFL) prevalence is increasing due to the escalating Atrial Fibrillation (AF) ablations and cardiac surgeries. We wanted to explore the outcome of the AAFL ablation, considering the recent changes in mapping and ablation. Methods: This study was approved by the Institutional Review Board (IRB) of Mayo Clinic hospital. We retrospectively studied 419 patients who had undergone AAFL ablation at Mayo Clinic from January 2017 to June 2022. Thirteen patients declined research authorization, and 19 patients were lost to follow-up during the 90-day blanking period, resulting in a sample size of 387. The median follow-up time for patients was 25.7 months (95% CI 23.7, 32.3). Results: Recurrent symptoms with documentation of atrial arrhythmia Occurred in 226/387 (58.4%) patients, of which 151/226 (66.8%) occurred within the first year. The median time to recurrence was 8.5 months (max 57.8 months). Eleven patients died during the study period, 9 of whom experienced recurrence prior to death. Overall, the median recurrence-free survival (RFS) time was 16.6 months (95% CI 13.2, 20.0) with a 1-year RFS rate of 57.2% (95% CI 52.2, 62.7%). Acute termination occurred 324/387 (83.7%) during the ablation. The 1-year RFS rate was 58.9% (95% CI 53.5%, 64.9%) for patients with acute termination and 49.0% (95% CI 37.9%, 63.4%) for those without acute termination. The rate was not significantly different based on acute termination status (p = 0.11). Conclusions: The one-year RFS rate of 57.2% following AAFL ablation, even though 83.7% achieved acute termination during the procedure, signifies the extent of the underlying substrate abnormalities.

Background: It is unknown whether cryoballoon technology for persistent atrial fibrillation (AF) is a reasonable initial strategy for patients with persistent AF (perAF). Methods: 390 consecutive procedures using cryoballoon for initial AF ablation were evaluated and divided first by clinical presentation: paroxysmal AF (PAF) or perAF, and then whether PV potentials associated PV pacing (PV capture) were identified after ablation. Patients were followed for recurrent AF (median 20 months). Results: PV capture was identified in patients with PAF and perAF (PAF: 20.3% vs. perAF: 14.6%; p < 0.05). No patient charactieristic differences were identified between those patients with or without PV capture. The presence of PV capture was not associated with different outcomes in patients with PAF. However, in patients with perAF, the presence of PV capture was associated with long-term outcomes similar to patients with PAF and significantly better than patients with perAF without PV capture (p < 0.001). In patients with perAF and PV capture, a strategy of reisolation of the PVs only for recurrent AF resulted in 20/23 (87%) patients in sinus rhythm off antiarrhythmic medications at study completion. In patients with PV capture, specific electrophysiologic properties of PV tissue did not have an impact on AF recurrence. Conclusion: PV capture (and not specific PV electrophysiologic characteristics) was associated with decreased recurrent AF in patients with perAF. PV capture may identify those patients with perAF in whom PV isolation alone is sufficient at initial ablation procedure and also as the primary ablation strategy for recurrent AF.