[Comparison of the ultrastructural and clinical studies on myocardium in patients with congenital heart disease].

Right ventricle myocardium of 25 cases of tetralogy of Fallot and 11 cases of ventricle septal defect were studied by both light and electron microscopy. Normal human myocardium from 4 cases were used as the control. The resulting data indicate that the mean muscle diameter correlated significantly with the course of disease, mean pressure of right ventricle and diameter of ventricle septal defect. In 6 cases with congenital heart disease, the myocardium was atrophic and presented with 2 types of ultrastructural features: accumulation of Z-line material or hyperplasia of the mitochondria. The significance of these ultrastructural findings in congenital heart disease is discussed.