Characteristics of Recurrent Atypical AFL
Among the 102 patients who underwent repeat ablation for atypical AFL, 79 patients presented in AFL on the day of repeat ablation, and 23 presented in sinus rhythm (Figure 1). For those patients presenting in NSR, AFL was successfully induced with standard pacing protocols in 14/23 patients. Most patients had at least one documented atypical AFL, and the number of flutter circuits ranged from 0 to 5 (Table 3). Atypical AFL could not be documented in 9 (8.7%) of the patients during the ablation. A total of 36 (35.6%) of the patients had roof dependent flutters. Peri mitral flutters were seen in 24 (23.8%) of the patients, and 33 (32.7%) patients had other flutter forms (idiosyncratic flutter circuits involving prior lesion sets; multiple-loop flutter circuits; transitioning flutters that were not durable enough for adequate mapping).