Cardiac hypertrophy of unknown etiology in young adults. A clinical and pathological study of three cases

Three cases have been described presenting an unfamiliar clinical picture. The main features were great cardiac enlargement, intraventricular thrombosis with embolisms to the viscera, and death within a year after the symptoms were well established. There were no signs of valvular disease or arteriosclerosis, and the blood pressure was at the normal level or slightly below it. Microscopic examination of the myocardium showed hypertrophy of muscle fibers in all, infarcts in varying stages of degeneration and repair in two, and in one of these, a curious hydropic degeneration of the heart muscle cells with vacuolization of the sarcoplasm. The third case showed only a few hemorrhages between the muscle bundles. No inflammatory changes or signs of arteriolar disease were observed. Though clinically the patients presented many essential features in common, the lesions at autopsy were not identical. It was not possible to state whether these cases represented a single condition at different phases of its development or were entirely unrelated in their pathogenesis. The etiology remained obscure.