Tests for myocardial infarction include electrocardiography, cardiac enzyme profile, coronary angiography, and other tests. 1. ECG examination can indicate cardiac ischemia. Based on analyzing the difference between multiple ECGs, i.e. dynamic changes, it is possible to understand the trend of cardiac ischemia, the extent of myocardial infarction, and assess the efficacy of treatment. 2. Cardiac marker test is used to reflect the heart function, cardiovascular inflammation, cardiac tissue damage of serological examination, which can indicate the extent of myocardial infarction to a certain extent. 3. Coronary angiography: it can provide detailed vascular information, which can help to guide the treatment and assess the prognosis. 4. Other tests: echocardiography, radionuclide scanning, cardiac perfusion scanning, etc. can be used to a certain extent to assess myocardial perfusion, myocardial viability and function. If a person with no previous heart disease suddenly develops chest pain, or if a person with known heart disease suddenly develops chest pain, shoulder and back pain, epigastric pain, dizziness, nausea, etc., he/she should immediately call the 120 emergency number to seek medical treatment in time and complete the relevant examinations under the guidance of the doctor to make a clear diagnosis.