Myocardial ischemia is attributed to the narrowing or blockage of the coronary artery supplying the heart, so the following tests can provide certain reference diagnostic value: 1. ST-segment depression in the corresponding lead of the ECG is greater than or equal to 0.05mV, or T-wave inversion in the corresponding lead may suggest the possibility of myocardial ischemia supplied by the corresponding vessel. 2. Under X-ray guidance, it is possible to clearly see whether the coronary artery injected with contrast agent is stenosed or occluded, so as to deduce the corresponding ischemic myocardium. 3.Coronary CTA is one of the important means of non-invasive detection of coronary artery disease, and the principle is similar to that of coronary angiography, but the accuracy is lower than that of coronary angiography. 4.Nuclear myocardial imaging is a non-invasive test for the distribution of radioactive elements directed to the myocardium, which can infer the extent of corresponding myocardial ischemia.