Acute coronary syndrome in a patient with a single coronary artery arising from the right sinus of Valsalva.

Coronary artery anomalies are usually encountered as coincidental findings during coronary angiography or at autopsy. Life threatening symptoms, such as arrhythmias, syncope, myocardial infarction, or sudden death, can occur in up to 20% of patients. However, the majority of anomalies (80%) are benign and asymptomatic. A single coronary artery (SCA) is one of the most rarely seen coronary anomalies with an incidence of 0.05%. We report the case of a 55-year old male patient who presented with symptoms of chest pain associated with an acute myocardial infarction. Coronary angiography revealed an anomalous left main coronary artery (LMCA) originating from the right coronary ostium, and an occluded distal right coronary artery. The occluded distal right coronary artery was successfully treated by thrombosuction and stenting. In order to confirm the origin and course of the SCA, multi-slice computed tomography (MSCT) of the heart was performed after coronary angiography. MSCT showed that the anomalous LMCA originated from the right coronary artery ostium and then passed the interventricular septum, instead of being intra arterial, and under the right ventricular infundibulum. The anomalous LMCA was classified as R-II S subtype according to Lipton's classification.