cTnl (cardiac troponin I) is a subtype of cardiac troponin, normal people have very low blood content, when cardiomyocytes are damaged, cTnl content in the blood rises rapidly, cTnl has become one of the most clinically valuable myocardial injury markers. Myoglobin MYO molecule is small and can directly enter the blood circulation without passing through lymph nodes, so when the myocardium is mildly damaged, it directly enters the blood circulation from cardiomyocytes. The creatine kinase isoenzyme CK—MB is mainly present in the myocardium. CK-MB can be used as an indicator to detect disease progression and guide treatment.