Cardiac blood tests include BNP and cardiac enzymes. The Chinese name of BNP is B-type natriuretic peptide, which is an indicator of heart failure. It is secreted by ventricular myocytes, and its secretion changes with intracardiac pressure. The higher the intracardiac pressure, the more BNP is secreted, and the higher the BNP measured by blood collection. When a patient has heart failure, the blood in the ventricles is not pumped out, resulting in increased pressure in the ventricles and increased BNP secretion. Cardiac enzymes, as the name suggests, are enzymes contained within the heart muscle cells and are indicators of myocardial infarction. When myocardial cells are damaged leading to necrosis, the enzymes in the myocardial cells will be released and the cardiac enzymes measured by blood collection will be elevated. Cardiac enzymes include creatine kinase and its isoenzymes, lactate dehydrogenase and its isoenzymes, and troponin. The most specific cardiac enzyme is troponin. The most specific of the cardiac enzymes is troponin, which requires active medical attention and improvement of the relevant tests.