Isolated left ventricular noncompaction: an unclassified cardiomyopathy with severe prognosis in adults.

Noncompaction of the ventricular myocardium is a rare congenital cardiomyopathy, which appears to represent an arrest in intrauterine endomyocardial morphogenesis. It is diagnosed both in children and adults. Its common presentation involves heart failure symptoms, ventricular tachyarrhythmias and thromboembolic events, but the age of onset varies widely.