Thallium-201 myocardial imaging in patients with angina pectoris and anomalous aortic origin of the circumflex coronary artery.

Anomalous aortic origin of the circumflex coronary artery is the commonest coronary artery anomaly. In this study, the significance of anomalous aortic origin of the circumflex coronary artery was investigated in seven patients with exertional chest pain using exercise thallium scintigraphy. Five patients with circumflex coronary arterial disease served as controls. Myocardial perfusion was normal in the five patients with a nonstenosed anomalous artery. In these patients, exercise heart rate and blood pressure response were normal. Two patients with a stenosed anomalous circumflex coronary artery and four of the five control patients had posterolateral myocardial perfusion defects. It is concluded that anomalous aortic origin of the circumflex coronary artery does not cause impairment of myocardial perfusion unless it is the site of significant coronary arterial stenosis.