Isolated noncompaction of ventricular myocardium

Isolated noncompact-ion of the ventricular myocardium is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogene sis. The diagnosis can be made echocardiographically, and the entity may be associated with problems of cardiac rhythm. We describe two illustrative c ases, with Wolf-Parkinson-White syndrome in one, and left bundle branch blo ck in the other. We emphasize that children with problems of rhythm and fin dings suggestive for left ventricular cardiomyopathy, either hypertrophic o r dilated; should be investigated to exclude isolated noncompaction of the ventricular myocardium.