[Dilated cardiomyopathy in childhood: intravital differentiation of endocardial fibroelastosis using transvascular endomyocardial biopsy].

Possibly due to the lack of clinical reports concerned with dilated cardiomyopathy in childhood, pediatric cardiologists may inadvertently designate the angiographic finding of a dilated left ventricle as endocardial fibroelastosis. We report historical and noninvasively-obtained data from twelve children, aged seven months to 17 years, with poorly-functioning dilated left ventricles, in whom no differentiation between the two diseases was enabled. Only by means of transvascular endomyocardial biopsies, performed during cardiac catheterization with a 6-F guide-catheter and a Machida bioptome for light and electron microscopal examination, was differentiation achieved among six patients with endocardial fibroelastosis and six with the nonspecific histological findings of muscular hypertrophy, interstitial fibrosis and marked degenerative changes. After exclusion of noxious and inflammatory etiologies, even in childhood, the diagnosis of primary dilated cardiomyopathy must be regarded as established. Since experience previously reported with endocardial fibroelastosis has not been based on histologic documentation of the diagnosis, questions with respect to natural history and prognosis remain unanswered.