Diagnostic criteria for myocardial enzymes in myocarditis

Nowadays, when we treat diseases, we cannot do without various examination items. There are many examination items for myocarditis, such as electrocardiogram and echocardiogram, etc. However, the examination and diagnosis of myocardial enzymes are different from myocarditis. Therefore, everyone must distinguish between these two examinations in normal times and choose the appropriate and corresponding ones to do a good job, otherwise it will cause unnecessary trouble and side effects.

Can it be used to diagnose myocarditis?

Generally speaking, the diagnosis of myocarditis requires comprehensive consideration of the specific manifestations, electrocardiogram, medical history, myocardial enzyme test results, etc. Myocarditis cannot be diagnosed based solely on the elevated creatine kinase isoenzyme. If there are other symptoms of myocarditis, a history of viral infection, and elevated creatine kinase isoenzymes, the possibility of myocarditis should be considered.

Normal values ​​of five myocardial enzymes :

1. Lactate dehydrogenase LDH: 100~240 IU/L;

2. Aspartate aminotransferase AST: 0~40 IU/L;

3. Creatine kinase CK: 24~194 IU/L;

4. Creatine kinase isoenzyme CK-MB: 0~25 IU/L;

5. Alanine aminotransferase ALT: 0~40 IU/L.

When LDH is high, it can cause acute myocardial infarction, skeletal muscle damage, certain hepatitis, leukemia, cirrhosis, obstructive jaundice and malignant tumors. During a myocardial infarction, LDH will be high for 12-24 hours, reach a peak at 48-72 hours, and return to normal after 1-2 weeks. LDH in the late stage of malignant tumors and in the pleural and abdominal effusions caused by malignant tumors will be high. In patients with chronic glomerulonephritis, SLE, diabetic nephropathy, etc., urinary LDH can reach 3-6 times that of normal people. The urine contains a variety of substances that inhibit LDH activity, such as urea and small molecule peptides. Low pH can also inhibit LDH activity. The LDH level of patients with uremia is normal, and it will increase after dialysis because the urea level in the body is high. We can observe related diseases in the body through five tests of the myocardial enzyme spectrum.

HBD, LD, AST, CK and CK-MB together constitute the myocardial enzyme spectrum, which is of great significance for the diagnosis of myocardial infarction. The serum LD/HBD ratio of healthy adults is 1.3:1.6, but the serum HBD activity of patients with myocardial infarction increases and the LD/HBD ratio decreases to 0.8:1.2.

It is reported that patients in the acute stage of stroke and acute cerebrovascular disease have increased myocardial enzymes. The reason may be that the damage or destruction of brain tissue releases more enzymes, which leads to increased sympathetic nerve excitability, increased catecholamine secretion, and accumulation of catecholamines in myocardial tissue, resulting in secondary myocardial damage and increased myocardial enzyme values ​​in serum.

In addition, studies have shown that elevated myocardial enzymes can occur in many diseases that can cause damage to myocardial cells, skeletal muscle cells and other tissue cells, such as active rheumatic heart disease, viral myocarditis, dermatomyositis, nephritis, pneumonia, and some malignant tumors, leukemia, etc.

The above is the relevant content of "What is the standard of myocardial enzyme and what is its use in diagnosing myocarditis". If you want to know more about myocarditis, you can read the relevant articles below or consult a doctor.