Endocardial fibroelastosis is a disease of the endocardium. The main pathological changes are the proliferation of subendocardial elastic fibers and collagen fibers, and the lesions are mainly in the left ventricle. Most cases develop within 1 year of age. The cause is not completely clear, but some cases may develop from viral myocarditis; insufficient endocardial blood supply and hypoxia may also be the cause. Primary endocardial elastosis has no significant valve damage or other congenital cardiac malformations. In contrast, secondary endocardial elastosis has congenital heart disease of the left heart obstruction type such as aortic constriction, left heart dysplasia syndrome and aortic valve atresia or stenosis. Clinical manifestations】The main manifestation is congestive heart failure, which can be divided into three types according to the severity of symptoms. 1, fulminant onset of disease, sudden onset of dyspnea, lip cyanosis, pallor, irritability, tachycardia, hypocardia, can hear the gallop rhythm, the lungs often hear dry and wet retching, liver enlargement, a few appear cardiogenic shock, and even sudden death within a few hours. This type is mostly seen in infants within 6 months of age. 2, acute type The onset is also rapid, but the development of heart failure is not as rapid as the fulminant type. It is often complicated by bronchitis, and fine wet retching sounds appear in the lungs. In some patients, cerebral embolism occurs due to the dislodgement of wall clots in the heart chambers. The age of onset of this type is the same as that of the fulminant form. If left untreated, most patients die of heart failure. 3.Chronic type The symptoms are the same as the acute type, but progress slowly. The growth and development of the child is more backward. With appropriate treatment, it can be relieved and survive to adulthood, but death can still occur due to recurrent heart failure. Diagnosis】 1. ECG Mostly left ventricular hypertrophy, a few show right ventricular hypertrophy or combined left and right ventricular hypertrophy, extensive ST segment level shift and T wave inversion. 2.Chest x-ray The left ventricular hypertrophy is obvious, the pulsation of the left heart edge is mostly weakened, and the lung texture is increased. 3.Echocardiogram The left ventricle is obviously enlarged, mitral valve and tricuspid valve regurgitation, heart systolic and diastolic function are reduced, and the endocardial echo is enhanced and thickened, which are the typical features of this disease. Treatment】The main applications are digoxin, diuretics, ACEI to control heart failure and prednisone to suppress immunity, which generally respond well and need to be taken for a long time until the symptoms disappear and the X-rays and ECG return to normal for 1 to 2 years before stopping. When combined with pulmonary infection, antibiotics and other treatments should be given. If the disease is not treated, most of them die before the age of half a year. Those who are well treated with digitalis and can adhere to the treatment for a long time have a better prognosis, and most of them can be cured.