The diagnostic criteria for viral myocarditis mainly depend on clinical manifestations

Everyone is familiar with the disease of viral myocarditis. Both children and middle-aged and elderly people may suffer from this disease. In recent years, with the increasing incidence of myocarditis, experts say that if you have viral myocarditis, you should take the correct treatment in time. If the treatment time is delayed or the treatment effect is not good, it will induce the occurrence of complications of myocarditis, which will cause great harm to the patient's health. So, what are the symptoms of viral myocarditis?

1. Clinical diagnosis basis

1. Heart failure, cardiogenic shock or cardio-cerebral syndrome.

2. Enlarged heart (one of the manifestations in X-ray and echocardiography examinations).

3. ECG changes: ST-T changes in 2 or more main leads (I, II, aVF, V5) dominated by R waves lasting for more than 4 days with dynamic changes, sinoatrial block, atrioventricular block, complete right or left bundle branch block, coupled rhythm, polymorphic, multi-source, paired or parallel premature beats, ectopic tachycardia caused by non-atrioventricular node and atrioventricular reentry, low voltage (except newborns) and abnormal Q waves.

4. CK-MB is elevated or cardiac troponin (cTnI or cTnT) is positive.

2. Etiological diagnosis basis

1. Diagnostic indicators: Examination of the child's endocardium, myocardium, pericardium (biopsy, pathology) or pericardial puncture fluid can confirm that myocarditis is caused by a virus if one of the following is found: ① Isolation of the virus. ② Detect viral nucleic acid using a viral nucleic acid probe. ③Specific viral antibodies are positive.

2. Reference basis: If one of the following is combined with clinical manifestations, myocarditis may be considered to be caused by a virus: ① The virus is isolated from the child's feces, throat swab or blood, and the antibody titer in the recovery serum is more than 4 times higher or lower than that in the first serum. ② In the early stage of the disease, specific IgM antibodies are positive in the blood of children. ③ Use viral nucleic acid probe to detect viral nucleic acid in the blood of the child.

3. Diagnosis basis

1. With two clinical diagnostic bases, a clinical diagnosis of myocarditis can be made. The diagnosis is supported by evidence of viral infection at the same time as or 1 to 3 weeks before the onset of the disease.

2. If one of the etiological diagnosis bases is met, it can be diagnosed as viral myocarditis. If one of the etiological reference bases is met, it can be clinically diagnosed as viral myocarditis.

3. If there is no basis for diagnosis, necessary treatment or follow-up should be given to confirm or exclude myocarditis based on changes in the condition.

4. Rheumatic myocarditis, toxic myocarditis, congenital heart disease, connective tissue disease, myocardial damage caused by metabolic diseases, hyperthyroidism, primary cardiomyopathy, primary endocardial fibroelastosis, congenital atrioventricular block, cardiac autonomic dysfunction, β-receptor hyperfunction and electrocardiogram changes caused by drugs should be excluded.