An incidental finding of unroofed coronary sinus during angiography confirmed by 3D echocardiography; A case report.

Unroofed coronary sinus (UCS) is an uncommon congenital heart anomaly and the most unusual type of atrial septal defect. This report presents a 71-year-old female with palpitation and dyspnea following an emotional stress, who was referred for ablation of typical atrial flutter. Finally diagnosed with a partially unroofed CS causing a bidirectional shunt.