Circumflex Coronary Artery Fistula Draining into Coronary Sinus.

Coronary artery fistula draining into the coronary sinus is a rare vascular malformation, and its diagnosis and clinical manifestations usually occur late. We describe the case of a 72-year-old female patient with dyspnea on exertion (New York Heart Association Class III) associated with palpitations. The transthoracic echocardiogram showed significant tricuspid insufficiency.