BACKGROUND: This case study demonstrated that although highly symptomatic, agenesis of the left circumflex artery was a benign finding. Anomalies of the coronary arteries were found to be the cause of sudden death in a young individual. Left circumflex anomalies were not associated with major cardiac events.

CASE REPORT: A 20-year-old male was admitted due to syncope preceded by chest pain. His electrocardiogram (ECG) showed global ST segment elevation as well as biphasic T waves in anterior precordial leads. Troponin T values were normal. Echocardiography was normal. Computerized axial tomography (CAT) scan showed agenesis of the circumflex artery with a super-dominant right coronary artery. Myocardial scintigraphy showed no perfusion defects. Exercise test did not present any arrhythmias. Tilt table test displayed stable blood pressure and pulse response. A reveal recorder registered no malignant arrhythmias. A coronary angiography confirmed the finding of the CAT scan and showed no collateral vessel development.

CONCLUSIONS: This case demonstrated that agenesis left circumflex artery although presenting with severe symptoms, such as chest pain, is a benign finding. Chest pain was not correlated to perfusion defects in this case. Although the patient experienced loss of consciousness, there was no objective support for cardiac origin as no malignant arrhythmias were found.

Keywords: Angina Pectoris, Congenital Abnormalities, Syncope