Left Circumflex Aneurysm With Coronary Sinus Fistula In a Middle-aged Man: A Case Report

Coronary artery aneurysms (CAAs) and coronary artery fistulas (CAFs) are rare abnormalities. CAA is an abnormal dilatation of the coronary artery while CAF is an unusual connection between a coronary artery and other cardiac structures. We report a case of a 55-year-old male with a history of atrial fibrillation and mitral regurgitation who was diagnosed with a left circumflex artery aneurysm, with a fistula connecting to the coronary sinus. He subsequently underwent an aneurysm resection, along with coronary artery bypass grafting (CABG) and mitral valve replacement. In this case report, we underscore the importance of early identification of this rare condition, as timely intervention mitigates potential complications, including coronary aneurysm rupture.