A patient with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) may present with signs and symptoms of myocardial infarction and congestive heart failure in infancy, or the condition may be unassociated with myocardial infarction or symptoms of heart disease until detected serendipitously in adulthood or at autopsy.

The ideal treatment of ALCAPA is to detect the presence of the anomaly before myocardial infarction occurs and to establish a coronary system that prevents myocardial infarction. All cases in infancy, however, come to medical attention only after myocardial ischemia and infarction have occurred. Attempts to establish a two-coronary-artery system for patients with ALCAPA are indicated when the condition is discovered.

Anomalous origin of the left coronary artery from the right sinus of Valsalva is a rare but important malformation because it is associated with a significant risk of sudden death (Fig. 43.3). Sudden death presumably is due to myocardial ischemia as a result of compression of the left coronary artery between the aorta and the pulmonary artery, an elliptical rather that a circular os of the left coronary artery, and compromise of the lumen of the left coronary artery due to acute angulation near its origin. Patients usually are asymptomatic until sudden death occurs, although some patients may have symptoms of angina or coronary insufficiency. Symptoms may include syncope or light-headedness associated with exercise.