The causes of cardiomyopathy in children are: i. It may be due to genetic mutation and congenital hypertrophic cardiomyopathy, because this disease, if it occurs in children, is mostly caused by genetic mutation. Second, the etiology may also be due to a lack of oxygen in the child while the child is in the mother’s body for various reasons, such as infection during the mother’s pregnancy, obstructed labor, excessive amniotic fluid, and overdue delivery, which may result in a lack of oxygen in the child and further cause congenital hypertrophic cardiomyopathy or congenital dilated cardiomyopathy. Third, the cause of the disease may also be due to exposure to rays, hair dye, etc., while in the mother’s body, the emergence of heart valve disease, secondary to cardiomyopathy. Fourth, children with low resistance are infected by viruses and develop viral cardiomyopathy, which gradually develops into dilated cardiomyopathy.