An autopsy case of cardiomyopathy with restrictive physiology in a child.

An autopsy case of cardiomyopathy with restrictive physiology associated with subendocardial myocardial necrosis and fibrosis in a seven-year-old child is described. Cardiac catheterization showed high left ventricular end-diastolic pressure with a dip-and-plateau pattern. Macroscopically, marked dilatation with fibroelastosis in both atria and mild dilatation in both ventricles were observed. Histologic examination revealed extensive subendocardial necrosis with marked disorganization of myocardial cells and moderate arteriolosclerosis. We speculate that these extensive myocardial lesions, which contributed to the restrictive hemodynamic changes, could have been induced by anoxia or a Ca2+ transport abnormality of unknown cause.