ABSTRACT
Anomalous aortic origin of a coronary artery (AAOCA) can cause sudden death, especially in young athletes. AAOCA does not have any clinical cardiovascular manifestations and sudden death is often the first manifestation ; hence, it is difficult to diagnose AAOCA before a major episode occurs. We report the case of a 58-year old woman with a right coronary artery arising from the left sinus and passing between the aorta and the pulmonary artery. Although the results of the exercise treadmill test and various other tests were normal, this patient underwent coronary artery bypass, surgery using the right internal thoracic artery to preventing sudden death. Two years after the operation, she is asymptomatic and has normal results on the exercise treadmill test.