Pulmonary vein isolation for paroxysmal atrial fibrillation in a patient with stand-alone unroofed coronary sinus

Introduction Atrial arrhythmia is common in patients with an atrial septal defect (ASD). Atrial fibrillation (AF) is the main cause of morbidity in older patients with ASD. An unroofed coronary sinus (CS) is rare (in,1% of all types of ASD) and is often associated with persistent left superior vena cava (PLSVC) and other forms of complex congenital heart disease and heterotaxy syndromes. Unroofed CS rarely occurs alone. This is a unique report of pulmonary vein isolation (PVI) for paroxysmal AF in a patient with stand-alone unroofed CS.