Two cases of anomalous origin of LAD from right coronary artery requiring coronary artery bypass.

We experienced two cases with anomalous origin of the left anterior descending artery (LAD) from the proximal right coronary artery requiring coronary artery bypass grafting. A 66-yr old female with a long history of angina and a positive stress test had the anomalous artery coursing anterior to the right ventricular outflow tract. A 42-yr old male with worsening angina after an anteroseptal myocardial infarction had the anomalous artery running between the great vessels. Both patients underwent left internal mammary artery-to-LAD bypass on the beating heart with complete resolution of ischemic symptoms. Isolated coronary artery anomaly is an uncommon disease (0.6-1.2%) in patients undergoing cardiac catheterization. An anomalous origin of the LAD from the proximal right coronary artery (RCA) or the right sinus of Valsalva (RSV) is very rare, found in 1.2-6.1% of all coronary anomalies. This coronary anomaly has been considered potentially serious but functionally unimportant. We report two cases of anomalous LAD from the proximal RCA resulting in anterior wall ischemia which was effectively treated by coronary artery bypass surgery.