Possible causes of exercise induced syncope or sudden death in young athletes include undetected cardiomyopathies, myocarditis, arrhythmias (especially inherited arrhythmia syndromes—such as long QT syndrome, Brugada syndrome), coronary artery abnormalities and disease, and aortic rupture.1 2 3 Coronary artery anomalies are of special interest as they are potentially treatable lesions.4 5 The most frequent coronary artery anomaly is anomalous origin of the left coronary or the left anterior descending artery from the right coronary sinus of the aorta. According to a recent north Italian study, anomalous origin of left or right coronary artery from the opposite aortic sinus is the third most frequent cardiovascular cause of deaths associated with exercise among athletes aged 12-35 years.2

We report on two adolescents who presented with a history of recurrent exertional pain and syncope during exercise. The results of previous cardiological evaluation—including 12 lead electrocardiography, exercise testing, and echocardiography—had been normal. Both patients were admitted to our hospital after life threatening events of ventricular fibrillation. The diagnosis of the coronary artery anomaly was detected in both patients by transthoracic echocardiography. These two cases show that this potentially fatal anomaly cannot be excluded by a negative exercise test.1 4