Anomalous origin of left coronary artery from pulmonary artery in association with intracardiac lesions. Report of two cases.

Two cases are presented to illustrate the diagnostic and therapeutic dilemma when an anomalous origin of the left coronary artery from the pulmonary artery occurs with a hemodynamically significant intracardiac lesion. Hemodynamic alterations resulting from the associated intracardiac lesion may obscure the clinical features of the coronary arterial abnormality, and the appearance of normal coronary arterial distribution with left ventricular or aortic root angiography may create a false impression of a normal origin of the coronary arterial supply. A high index of suspicion may be the only lead to the detection of an anomalous origin of the left coronary artery from the pulmonary artery in association with an intracardiac lesion. In addition to the intracardiac lesion known to be associated with coronary arterial abnormalities, the question of anomalous coronary supply should be raised by the finding of poor left ventricular function or mitral insufficiency after operation (unexplainable by other causes), by the development of poor myocardial function during cardiac catheterization or anesthesia, or by the significant enlargement of a coronary artery seen during left ventriculography or supravalvular aortography.