Introduction
Patients undergoing cavotricuspid isthmus (CTI) ablation of typical right atrial flutter (AFL) frequently develop new-onset atrial fibrillation (AF) within three years after ablation.1-3 Previous studies investigating risk factors for incident AF after AFL ablation have yielded inconsistent results, and have not commonly included detailed echocardiographic data, or electrophysiology study data.4-6 Recently, the HATCH score, a risk score incorporating hypertension, age >75 years old, stroke/transient ischemic attack, chronic obstructive pulmonary disease, and heart failure, has been proposed as a predictor of AF after AFL ablation,7-8 but its utility in clinical decision making remains unclear. Multiple randomized trials have demonstrated the benefit of prophylactic pulmonary vein isolation (PVI) for patients undergoing CTI dependent AFL ablation.9-13 However, prophylactic PVI during AFL ablation is not widely performed, and not included in clinical guidelines.14 Patients at greatest risk of developing incident AF after AFL ablation may derive the greatest benefit from either prophylactic PVI, or intensified monitoring to guide anticoagulation therapy.9-12 We aimed to investigate risk factors, including detailed echocardiography data, and invasive electrophysiology study data, for development of incident AF following AFL ablation.