Primary endocardial fibroelastosis is mainly the disease of infancy, but adult cases rarely have been reported. This disease is characterized by diffuse endocardial thickening due to the proliferation of elastic and collagenous tissue. The etiology and pathogenesis of this disease remains obscure.
A boy reported here ha d been apparently in good health until the age of 11, since when palpitation, nausea, vomitting, facial edema and epigastric pain developed. On a chest x-ray examination the heart was found to be greatly enlarged (CTR: from 0.62 to 0.72)and an electrocardiographic study revealed QS-pattern and inverted T-wave. He received treatment with digitalization, and repeated hospitalization and discharge from hospital. At the age of 13, following a lapse of common cold, his congestive heart failure rapidly deteriorated and he died 16 months after the onset of congestive cardiac failure.
At autopsy, the heart, weighed 370gm, was remarkably enlarged and hypertrophied, especially in the left ventricle. The endocardial surface of the left ventricle was smooth and yellow-white. Microscopic examination revealed diffuse proliferation of elastic and collagenous tissue in the endocardium, which had various thickness of about 500p to 3.0 mm. Multiple organizing thrombi were found in the mural endocardium of the left ventricle, some of which were covered by the thick layer of elastic and collagenous tissue. The myocardium of the left ventricle showed the mixture of atrophic and hypertrophic muscle fibers, furthermore fatty degeneration and diffuse interstitial fibrosis. Neither myocardial inflammation nor infarction was found. There were neither congenital cardiac anomalies such as Bland-White-Garland syndrome and aortic stenosis, nor the evidence of the congenital metabolic disorders such as glycogen storage disease. All the liver, spleen, lungs and other organs showed severe congestion, and especially the liver, weighed 870gm, did “nutmeg liver” -like appearance.
On the basis of these clinical and pathological findings, it is supposed that slight endocardial fibroelastosis was present in the left ventricle of this boy from birth, and has been increased in thickness gradually over a very long period as the result of being affected by some factors such as an elevated intra-ventricular blood pressure and a long-standing mild ischemia of endocardium.
For these reasons, he seems to have been able to maintain good health without cardiac symptoms or signs until the age of 11, despite the presence of the endocardial lesion. In conclusion, this autopsy case is regarded as a very rare and interesti ng one of primary endocardial fibroelastosis in point of having been able to survive until the age of 13.
