Familial nonobstructive cardiomyopathy with endocardial fibroelastosis beyond infancy.

A 10-year-old boy with congestive heart failure died in five months in spite of comprehensive medical treatment. Autopsy showed patchy areas of endocardial fibroelastosis of the left ventricle. The sister of this patient had followed a similar course at 13 years of age with death within six months of the onset of congestive failure. Her postmortem examination also showed endocardial fibroelastosis. The clinical presentation of familial endocardial fibroelastosis in the preteen and teenage years is a rare event. Probably the endocardial fibroelastosis was secondary to a familial nonobstructive cardiomyopathy.