Right coronary artery arising from the distal left circumflex artery

Origination of the right coronary artery from the distal left circumflex artery is a rare anomaly. A 63-year-old woman was admitted with subacute anteroseptal myocardial infarction. Electrocardiography showed a QS pattern in V1-V3 precordial leads without ST elevation. Cardiac enzyme levels were elevated (CK-MB 186 ng/ml, troponin I 27.1 ng/ml). Echocardiography showed hypokinesia of the anterior and lateral walls without valvular pathology. Coronary angiography revealed origination of the right coronary artery from the circumflex artery. The right coronary artery had a normal flow pattern and there were atherosclerotic plaques in the circumflex artery without a significant stenosis. Distal to the first diagonal branch of the left anterior descending artery, a 95% stenotic lesion was detected, which was treated with balloon dilatation followed by implantation of a bare metal stent. The patient was discharged with near-complete patency and without any complication.