Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA), a forgotten congenital cause of sudden death in the adult

Anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) is a very rare often fatal congenital coronary artery anomaly that occurs in approximately only 1 of 300,000 live births. Many cardiologists and pathologists may be unaware that cardiac ischemia and sudden death can also occur due to ALCAPA in adults in whom it is even rarer and thus may be missed at autopsy. The adult form may range clinically from asymptomatic to sudden cardiac death. We present four cases of adult ALCAPA that illustrate the variable presentations and survival. Two had died at rest and were previously asymptomatic. The other two died during exertion with history of recent chest pains in one and previous myocardial infarction in childhood in the other. This last case remained asymptomatic until death. These four cases highlight that surgery should be undertaken in all cases, even in those who are asymptomatic as newer imaging makes the diagnosis in life more frequent. Age is not important as cases vary widely in age from 22 to 68 in our small group. Furthermore, the most common site of left coronary artery origin is the left pulmonary sinus but our autopsy study shows that the origin can be variable extending above the pulmonary valve sinus to the main pulmonary artery.