Myocarditis in children is inflammatory damage to the heart muscle, most commonly caused by various viral infections, and its early manifestations vary, thus prompt medical attention is required once symptoms such as palpitations, chest tightness and chest pain are present after various infections. The clinical manifestations of myocarditis in children vary in severity, and symptoms depend on the extent and location of the lesion. Most children have prodromal symptoms of infection, such as fever, fatigue, muscle aches and other symptoms of upper respiratory tract infection or gastrointestinal symptoms such as nausea, vomiting and diarrhea, 1-3 weeks before the onset of the disease. Severe myocarditis can lead to cardiogenic shock and sudden death. Most of these children have dyspnea, edema, and even syncope and sudden death after prodromal symptoms, often due to severe arrhythmias, heart failure, and cardiogenic shock caused by extensive acute myocardial damage. Children with myocarditis have a variety of clinical manifestations, and thus it is less likely to rely on symptoms alone to diagnose myocarditis. Therefore, if palpitations, chest tightness and chest pain occur after symptoms such as fever, cough, sore throat, weakness, nausea and vomiting, one should be alert to the possibility of myocarditis.