Myocarditis is often the inflammatory manifestation of systemic diseases in the myocardium, due to the size of the myocardial lesions and the extent of the lesions, the mild can have no clinical symptoms, serious can lead to sudden death, timely diagnosis and appropriate treatment, can be completely cured, and those who do not heal, can form chronic myocarditis or lead to cardiomyopathy. I. Etiology Bacterial diphtheria bacilli, hemolytic streptococci, diplococcus pneumoniae, typhoid bacilli, etc. Viruses such as coxsackievirus, echovirus, hepatitis virus, epidemic hemorrhagic fever virus, influenza virus, adenovirus, etc., and others such as fungi, protozoa, etc. can cause myocarditis. However, viral myocarditis is currently more common. The pathogenic condition factors ① excessive exercise, exercise can cause the virus to multiply and replicate in the myocardium to increase, aggravating myocardial inflammation and necrosis. ②Bacterial infections, when bacteria and viruses are mixed, may play a synergistic pathogenic role. ③ Pregnancy: Pregnancy can enhance the reproduction of virus in the myocardium, and the so-called perinatal cardiomyopathy may be caused by viral infection. ④Other: malnutrition, high fever and cold, hypoxia, excessive alcohol consumption, etc., can induce viral myocarditis. The symptoms are more frequent in young adults, often preceded by manifestations of the primary infection, such as fever, sore throat, cough, vomiting, diarrhea, and muscle aches in viral cases. Most of the symptoms of myocarditis appear 1-3 weeks after the viral infection, and the palpitations can cause weakness due to lower blood displacement due to arrhythmia. When the pericardium and pleura are involved, chest tightness, chest pain, and angina-like manifestations may occur. In severe cases, cardiac insufficiency may occur. Common signs: sinus tachycardia is not parallel to body temperature. Sinus bradycardia and various arrhythmias may also be present. The enlarged heart border accounts for 1/3-1/2 of the cases, which are seen in severe myocarditis, as the enlarged heart may cause mitral or tricuspid valve closure insufficiency and systolic murmur in the apical region or left lower sternal border. In severe myocardial damage or heart failure, a diastolic gallop rhythm can be heard, the first heart sound is diminished, and in cases of combined pericarditis, a pericardial fricative sound can be heard. In mild cases, the heart may be completely asymptomatic, but blood pressure usually rises in the acute phase, leading to headache, dizziness and panic, chest tightness, chest pain, etc. In severe cases, the heart may fail or die suddenly. The performance varies. According to the clinical manifestations, there are six types: ① asymptomatic type: S-T changes on ECG 1-4 weeks after infection, no symptoms. (2) Arrhythmia type: various types of arrhythmias, with ventricular asystole being the most common. ③Heart failure type: Signs and symptoms of heart failure appear. ④Myocardial necrosis type: clinical manifestations are similar to myocardial infarction. ⑤ Enlarged heart type: enlarged heart with systolic murmurs in the mitral and tricuspid regions. (6) Hypertensive type: Clinically, it often parallels the active phase of myocarditis, and uncontrolled over time will result in left ventricular hypertrophy, septal hypertrophy, mitral tricuspid valve closure insufficiency, and other changes in cardiac structure unique to hypertension. (7) Sudden death type: no aura, sudden death. ECG: The positive rate of abnormal ECG is high and is an important basis for diagnosis. The ECG can suddenly change from normal to abnormal after the onset of the disease and disappear as the infection subsides. The main manifestations are T wave hypotension or inversion, ST?T change, R wave hypotension, pathological Q wave, and about 1/3 patients may have Ⅰ to Ⅱ degree atrioventricular block. 2.See hypertensive type in symptoms. 3.X-ray examination: due to the extent of lesions and the severity of lesions, radiological examination also varies greatly, about 1/3-1/2 heart enlargement, mostly mild to moderate enlargement, obvious enlargement is mostly accompanied by pericardial effusion, the heart shadow is spherical or flask-shaped, the heart beat is weakened, limited myocarditis or less severe lesions, the heart boundary can be completely normal. 4, blood tests: white blood cell count in viral myocarditis can be normal, high or low, blood sedimentation is mostly normal or slightly increased, C-reactive protein is mostly normal, GOT, GPT, LDH, elevated, creatine phosphokinase increased (CKP) elevated, blood sedimentation increased. 5. Virus isolation or antibody determination can be done if available. Bed rest should be given to reduce tissue damage and accelerate recovery of the lesion. With arrhythmia, bed rest should be 2-4 weeks, then gradually increase the amount of activity, severe myocarditis with heart enlargement, should rest for 6 months to a year, until the clinical symptoms completely disappeared, the heart size back to normal. Immunosuppressants: the application of hormones is still debated, but severe myocarditis with atrioventricular block, cardiogenic shock cardiac insufficiency can be applied hormones, commonly used prednisone, 40-60mg / day, gradually reduce the amount after the condition improves, 6 weeks a course of treatment. If necessary, hydrocodone or dexamethasone can also be used, intravenous administration. For heart failure, cardiac, diuretic and vasodilator are available. Anti-arrhythmic, etc. Myocardial repair medications: coenzyme Q10, vitamins, energy synergists, etc. Anti-hypertensive therapy can be standardized for those with hypertension. The sequelae period is based on symptom relief treatment, strengthening rest, preventing cold and flu, not doing strong physical labor, etc.