Case report. Fetal cardiac failure resulting from endocardial fibroelastosis.

An autopsy was performed on a female stillborn infant with generalized edema associated with ascites. On gross examination of the heart the pulmonary trunk was atretic from its origin of the heart to the bifurcation. The ductus arteriosus was abnormally wide. The right ventricle was hypoplastic and its endocardium was diffusely thickened. The inner surface of right ventricle appeared pale, obscuring the identification of trabeculae corneae and papillary muscles. At the posterior wall there was an extremely thin lesion where no apparnet cardiac muscle was contained. The tricuspid orifice was stenotic and the valve was hypoplactic. The right atrium was markedly enlarged and its wall was thickened. The foramen avale had patency of the valvular competent type. Atrial septal defect (ASD) was not present. The left ventricle was remarkably dilated with markedly thick wall. Ventricular septal defect (VSD) was present immediately beneath the right coronary cusp of the aortic valve. Light microscopic examination of the right ventricle revealed a marked increase of collagen and elastic fibers with extensive deposits of calcium not only in the endocardium but also in the deep portion of myocardium. Fibroelastosis appeared particularly prominent in the subendocardial layer. The muscle fibers surrounded by these penetrating fibers and deposits of calcium showed degeneration. The entire myocardial layer of the specific area in the right ventricle where the wall was paper-thin was fully replaced by fibers and calcium. Inflammatory cell infiltration was found only at some places of the pericardium. The left ventricular wall also showed fibroelastosis, although the degree of involvement was much less as compared to that seen in the right ventricle. There were no significant pathological changes in both atria.