Angiographic identification of primary coronary anomalies causing impaired myocardial perfusion.

The origin and early branching of the coronary arteries is fairly constant. Anomalous origin of the coronary arteries, which produced significant abnormalities of myocardial perfusion, were documented in 13 adult patients undergoing investigation because of chest pain. All underwent surgical treatment with relief of the presenting symptoms. They can be divided into four groups: (1) Origin of the left anterior descending branch of the left coronary artery (LCA) from the pulmonary artery (PA) (three cases); (2) origin of the LCA from the anterior sinus. Acute angulation of the ostium and compression of the intramural segment of this coronary produced severe myocardial ischaemia in three patients. (3) Origin of the LCA from the right coronary artery with its proximal segment closely related to the noncoronary sinus (one patient) in whom relief of symptoms was obtained by surgery. (4) Origin of the LCA from the PA with reversal of coronary flow and left to right shunting (six patients). It is concluded that anomalies of the origin of the coronary arteries are rare, but can produce specific clinicopathological entities that can be diagnosed with confidence and corrected surgically. Moreover, the study emphasises the need for angiographic awareness of these coronary anomalies, even in adult patients in whom atherosclerotic disease would be the most likely finding at cardiac catheterisation.