Single coronary artery anomaly: the left main coronary artery originating from the proximal segment of right coronary artery.

This case report we presented is that the anomalous left main coronary artery (LMCA) originates from the proximal segment of right coronary artery. In order to confirm the origin and course of the anomalous LMCA, a multi-slice computed tomography (MSCT) of the heart was performed on a 64-slice machine (Philips 64 Slice, Philips, USA) after 6 months of coronary angiography operation. The results showed that the anomalous LMCA originates from the proximal segment of right coronary artery, lies posteriorly to the aorta before taking acute sharply to go between the aorta and left atrium. It was classified as R-II P subtype according to Lipton's classification. It is a rare case in the clinical practice.