A case of twin circumflex arteries associated with acute myocardial infarction.

A circumflex (Cx) artery originating from the right coronary artery is one of the most common congenital coronary anomalies and is usually thought to be benign. Twin Cx arteries represent a very rare congenital anomaly with only three reported cases. Herein, we present a case of twin Cx arteries originating from the left main and right coronary arteries, respectively. A 50-year old male patient was admitted with chest pain. The electrocardiogram showed ST-segment elevation in leads D2, D3, and AVF, and ST-segment depression in the anterior leads. With the diagnosis of acute inferior myocardial infarction, the patient underwent coronary angiography which showed that the left Cx originating from the left main coronary artery was totally occluded by a thrombus in the mid-portion. There was another Cx arising from the proximal part of the right coronary artery with a significant stenosis in the proximal segment. Balloon angioplasty and stenting were successfully performed for the left Cx lesion, followed by direct stenting of the right Cx lesion one month later. The two Cx arteries were also evaluated by cardiac computed tomography angiography. The right Cx coursed between the pulmonary artery and the aorta and supplied the right part of the lateral wall of the left ventricle. The left Cx was located in the lateral wall and supplied the left part of the lateral wall of the left ventricle.