Abstract
BACKGROUND: Patients with adult congenital heart disease have a high risk of atrial flutter (AFL) because of multiple operations, and it is often difficult to treat them with medication alone. CASE SUMMARY: An 18-year-old female patient with repaired tetralogy of Fallot (rTOF) who developed drug-refractory AFL 2 years after a second surgery involving pulmonary valve replacement and removal of a previous right ventricular outflow tract patch presented to out hospital. Catheter ablation was successfully performed for typical cavotricuspid isthmus-dependent AFL without complications, and sinus rhythm was maintained at follow-up. DISCUSSION: Typical AFL is a treatable cause of arrhythmia in patients with rTOF even years after reoperation. Catheter ablation is a safe and effective definitive therapy for this population, despite complex surgical anatomy. TAKE-HOME MESSAGES: Vigilance for late-onset AFL is essential in patients with rTOF post-pulmonary valve replacement, particularly after major right ventricular outflow tract reconstruction. A systematic, multidisciplinary long-term follow-up strategy is crucial for optimizing outcomes in adult congenital heart disease.