Anomalous right coronary artery arising from left mainstem.

Various coronary artery anomalies occur in both symptomatic and asymptomatic individuals. We have described a unique case of an aberrant right coronary artery arising from the left mainstem, resulting in clinical myocardial infarction in the absence of coronary atherosclerosis. Though different anomalies of the right coronary artery have been described, we feel this case is unique in that the right coronary artery arises from the left mainstem, truly forming a single coronary artery.