Increased myocardial enzymes do not necessarily mean infarction, and the degree of myocardial ischemia is not directly related to myocardial enzymes. To diagnose myocardial infarction, in addition to myocardial enzymes, it is necessary to combine clinical symptoms, coronary artery CT and coronary angiography, of which coronary angiography is the gold standard for diagnosis. Myocardial infarction usually occurs in patients with coronary artery disease, may be due to physical activity or emotional excitement and other triggers, the patient suddenly appeared in the retrosternal pressure-like pain, accompanied by dyspnea and sweating, more than half an hour does not relieve, and oral nitrate drugs or fast-acting heart pills are ineffective. Electrocardiogram shows ST-segment bow-back upward elevation, cardiac enzymes, especially troponin elevation, and sometimes acute cardiac insufficiency, at this time, basically can be diagnosed as myocardial infarction, and need to immediately carry out coronary angiography to clarify the diagnosis, and at the same time, interventional therapy, stent implantation in order to open up the blockage of the coronary arteries. In addition to myocardial infarction, severe heart failure and myocarditis may also lead to elevated cardiac enzymes. Therefore, the diagnosis of myocardial infarction should be made by combining the patient’s symptoms and various auxiliary examinations, rather than relying on a single indicator.