Congenital atresia of the left main coronary artery with noncompaction of the ventricular myocardium in an asymptomatic young child.

Congenital atresia of the left main coronary artery (LMCA) is an extremely rare cardiac anomaly, and no cases have been reported from the mainland of China. The diagnosis for the 20-month-old boy in the reported case highlights the essentiality of comprehensive diagnostic measures. To avoid a misdiagnosis, electrocardiographic and echocardiographic evidence should be vigilantly explored in young children suspected of having dilated cardiomyopathy. This is the first case report of LMCA atresia associated with noncompaction of the left ventricular myocardium.