A case of right ventricular dilated cardiomyopathy.

This paper presents a sudden death case of 16-year-old girl. She is assumed to have died of ventricular arrhythmia clinically. On autopsy, the right cardiac ventricle was markedly dilated due to extensive infiltration of fibroadipose tissue and resultant depletion of the myocytes, but there was no full thickness disappearance of the contractile element in any part. Considerable parts of remaining myocytes showed degenerative changes similar to those of dilated cardiomyopathy. The left ventricle was moderately dilated. It showed similar significant degenerative changes to the right ventricle, but the degree was less extensive than the right. These findings do not fill the diagnostic requirements of neither Uhl's anomaly nor parchment heart, which reveal almost total depletion of the right ventricular myocytes. However, the findings were consistent with arrhythmogenic right ventricular dysplasia, in case the concept of the entity is extended, we concluded that it would be better to adopt a term--cardiomyopathy--to this case rather than dysplasia. Because, there were considerable histological evidence of myocardial degeneration suggesting primary myocardial disease rather than congenital defect in nature. We diagnosed, therefore, this case as right ventricular dilated cardiomyopathy, comprising a type of dilated cardiomyopathy whose myocardial lesions predominate in the right compared to the left ventricle.