[Anatomoclinical study of 100 cases of hypoplasia of the right ventricular muscle (including 89 unexpected sudden deaths). Relation with Uhl's anomaly].

The authors present the pathologist's view of Uhl's anomaly based on 100 cases recorded over 31 years, 89 of which came from medico-legal autopsies following sudden unexpected death in young subjects. The anatomic diagnosis is made by macroscopic examination of the whole heart in diffuse forms (parchment heart) and from transverse sections of the mid third of the ventricle in incomplete forms, showing absence of myocardium in the juxta-septal anterior wall of the right ventricle. The wall entirely made up of adipose tissue, may retain its normal thickness. On microscopy, normal adipose tissue is observed between the epicardium and endocardium, sometimes with islets of myocardium dispersed in the subendocardial layer and with, in about half the cases, subendocardial bundles of non-hyalinized collagen without any inflammatory cellular infiltration. Other structural histopathological lesions may complicate the malformation, involving the intraseptal arterioles or the conductive system. In addition to the 89 cases of sudden and unexpected death before the age of 50 (preceded by some modification of the patient's life style in 29 cases), 11 cases were symptomatic and 5 were transplanted with a good result. The clinical diagnosis of Uhl's disease is important because of its consequences: ventricular tachycardia and possible sudden death, more rarely cardiac failure with age. Histological analysis should take into account the constant presence of adipose tissue in the right ventricle, and should only interpret excessive quantities with associated myocytic aplasia as pathological.(ABSTRACT TRUNCATED AT 250 WORDS)