Frequency of atrial arrhythmias after atrial flutter ablation and the effect of presenting rhythm on the day of ablation.

Radiofrequency catheter ablation of the cavotricuspid isthmus is a proven therapy for typical atrial flutter (AFl); however, in some patients, new atrial arrhythmias (AA) may occur after AFl ablation. This study explored the difference in the occurrence of spontaneous AA after AFl ablation as a function of the patient's presenting rhythm on the day of the AFl ablation. A retrospective study of consecutive patients who underwent AFl ablation at Baylor University Medical Center at Dallas was performed. A total of 188 subjects were included; 50% (94) presented in AFl (Group AFl) on the day of the ablation procedure and 94 presented in sinus rhythm (SR; Group SR). Group AFl patients were older (P < 0.001), more likely to have diabetes (P = 0.03), and more likely to have undergone previous heart surgery (P = 0.03). The median size of the left atrium was 4 cm (range 2.8-6.8) in Group AFl compared with 3.8 cm (range 2.6-5.6) in Group SR (P = 0.009). Atrial fibrillation was induced during the ablation procedure in 7.5% and 21.3% of patients in Groups AFl and SR, respectively (P = 0.007). Overall, 29 of 188 (15.4%) patients developed new AA within 1 year of the procedure, 13.8% in Group AFl vs 17.0% in Group SR (P = 0.57). In conclusion, patients presenting for AFl ablation in SR were younger and healthier but had more atrial fibrillation induced during their ablation procedure, with a trend toward more postablation AA due to additional arrhythmia substrate.