Adult Anomalous Left Coronary Artery Arising From the Pulmonary Artery (ALCAPA) Syndrome as First Presentation With Atrial Fibrillation in a Marathon Runner.

Anomalous left coronary artery arising from the pulmonary artery (ALCAPA) syndrome is a very rare congenital heart disease with an incidence of one in 300,000 and a high rate of mortality early in life if left untreated. Adult-type ALCAPA presents when significant collaterals develop from the right coronary artery (RCA) to the left coronary artery (LCA). Even with the collaterals, chronic sub-endocardial ischemia occurs in most cases, and patients die from sudden cardiac death.