Diagnosis of ALCAPA syndrome in adults.

pulmonary artery (PA), receiving collaterals from a dilated RCA (Figure, B and D). Anomalous left coronary artery arising from the pulmonary artery (ALCAPA syndrome) is uncommon, although the true incidence may be underestimated because of the difficulties in diagnosing the condition in the absence of symptoms in adults. The diagnosis has been based on coronary angiography findings, but now MDCT can clearly establish the diagnosis and provide additional anatomic information before surgery. The patient refused any type of invasive treatment and remains stable at the time of writing, 8 months later.