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. The diagnosis is made by the combined appearance of numerous, excessively prominent trabeculations and multiple deep intertrabecular recesses perfused from the ventricular cavity, commonly involving the apical and midventricular segments of the left ventricle. Although the peculiar echocardiographic picture may possibly lead to the correct diagnosis, this condition may be often misdiagnosed or unrecognized since it is not widely known.