The isolated single coronary artery is a rare congenital anomaly, in which both coronary arteries arise from a solitary ostium. Diagnosis of coronary anomalies and identification of the exact anatomy of coronary arteries has significant clinical importance, hence, myocardial ischemia or sudden cardiac death is usually related to its course of anomalous coronary artery. Most patients with a single coronary artery are asymptomatic and have normal electrocardiogram and negative stress tests. However, if the patient has other structural abnormalities, for example, ventricular hypertrophy, the exam is determined. This report describes a case of single coronary artery, where the right coronary artery originated from the distal left circumflex artery in a patient with hypertrophic ardiomyopathy.

Prevalence of the coronary artery anomaly is approximately 1% of the population who undergo coronary angiography. The anomalous origin of the right coronary artery (RCA) as a branch of the left anterior descending artery (LAD) is a very rare variation of single coronary artery. The anatomic variation has no clinical significance. However, some patterns of congenital coronary artery anomalies can cause clinical manifestations of myocardial ischemia, reducing myocardial perfusion. We report on a case of a 78-year-old man who had anomalous RCA arising from the proximal part of the LAD, which probably caused chest pain.