1, signs and symptoms: cardiac manifestations within 3 weeks after upper respiratory tract infection, diarrhea and other viral infections, such as severe post-infection weakness, chest tightness, dizziness (due to reduced cardiac output), markedly diminished apical first heart sound, diastolic gallop rhythm, pericardial friction sound, heart enlargement, congestive heart failure or athlete’s syndrome that cannot be explained by general causes. 2, the following arrhythmias or ECG changes newly appeared within 3 weeks after the above infection: sinus tachycardia, atrioventricular block, sinus block or bundle branch block; multiple sources, paired ventricular premature, autonomous atrial or junctional tachycardia, paroxysmal or non-paroxysmal ventricular tachycardia, atrial or ventricular flutter or fibrillation; two or more leads with horizontal or downward sloping ST segment shift ≥0.01mv or ST segment abnormalities Elevation or abnormal Q waves. 3.Serum troponin I or troponin T and CKMB were significantly elevated during the course of the disease. Echocardiography showed enlarged heart chambers or abnormal ventricular wall motion and/or nuclear cardiac function tests confirmed reduced left ventricular systolic or diastolic function.