Background: Some patients undergoing catheter ablation for atrial fibrillation may develop typical atrial flutter on follow-up, and a second procedure for typical atrial flut-ter is often required in such patients. In this study, we aimed to define the variables asso-ciated with the development of typical atrial flutter after ablation.

Methods: One hundred fifty-nine patients who underwent catheter ablation for the first time due to atrial fibrillation and who did not have a previously documented atrial flutter were included in the study. Before ablation, baseline clinical features and echocardiographic parameters were recorded. At the 1st, 3rd, 6th, and 12th months after the procedure, and then annually, the patients were followed up for typical atrial flutter development.

Results: At a mean follow-up of 34.0 (14.0-50.0) months, typical atrial flutter developed in 21 (13.2%) patients. During the follow-up, right atrial diameter was greater in those who developed typical atrial flutter than those who did not [39.0 (38.0-43.0) vs. 36.0 (34.0-39.0) mm, P <.001]. A multiple Cox regression analysis showed that the right atrial diameter was the only independent predictor of typical atrial flutter development (hazard ratio = 1.12, 95% CI: 1.02-1.23, P =.021). A receiver operating characteristic analysis showed that the best cutoff for the right atrial diameter was 38.5 mm to predict typical atrial flutter development (area under the curve = 0.77, 95% CI: 0.67-0.86, sensitivity = 62%, specificity
= 75%, P <.001).

Conclusion: In patients undergoing catheter ablation for atrial fibrillation, a pre-procedural right atrial diameter measurement may predict typical atrial flutter development at follow-up. In particular, patients with a pre-procedural right atrial diameter ≥39 mm may be at a higher risk for developing typical atrial flutter in the future.