Giant aneurysmal fistula of the left main coronary artery to the right atrium.

A 42-year-old woman presented to our outpatient department with complaints of atypical chest pain and palpitation. On physical examination, the patient's blood pressure was 140/95 mm Hg, and there was a systolic cardiac murmur on the left sternal border. A transthoracic echocardiography examination was performed, and a left-to-right shunt ratio (Qp/Qs) of approximately 1.5 was detected. Computed tomography angiography and coronary angiography examinations confirmed the presence of a large fistula between the left main coronary artery and the right atrium, with giant aneurysm formation and an intact right coronary artery. Surgical closure of the shunt was performed with a good final result.