Pediatric myocarditis is a disease of systolic and diastolic dysfunction of the heart and cannot be self-tested, but can be diagnosed by going to the hospital for a clinical examination under the guidance of a doctor. Myocarditis is triggered by viruses, and children with myocarditis may have a history of viral infections, such as colds and diarrhea, etc. After 1 to 3 weeks, symptoms of cardiac impairment, such as muffled heart sounds, arrhythmia, and palpitations, may be present. You can go to the hospital for ECG, X-ray and laboratory tests. In the case of myocarditis there may be manifestations such as ST-T changes on the ECG, enlarged heart shadow, and elevated troponin. The diagnosis of pediatric myocarditis needs to be carried out under the guidance of doctors and standardized treatment. Do not make blind judgment on your own to avoid delaying the condition.