Coronary atherosclerotic heart disease is due to coronary atherosclerosis caused by the narrowing of the blood vessel lumen and lead to insufficient blood supply to the heart muscle of the heart disease, is a common disease of the middle-aged and elderly groups, seriously jeopardizing human health. Coronary heart disease in our country on the incidence of coronary heart disease shows a year-on-year increase in the trend of outpatient clinics, there are a lot of patients to consult, often ask the doctor the same question: I this is coronary heart disease? Is it serious? How can I make it clear that it is coronary heart disease? Do I need medication or surgery? At this time, the general doctor can not decisively answer these questions, because the diagnosis of coronary heart disease needs to have a narrowing of the blood vessels of the heart, and the narrowing of the heart tissue significantly affects the blood supply, resulting in clinical symptoms before considering the diagnosis of coronary heart disease. So what tests can be done to find out whether there is a narrowing of the coronary arteries and the severity of the coronary stenosis? Nowadays, the two commonly used tests are coronary CTA and coronary angiography. First of all, let’s understand the difference between the two, in order to facilitate the choice. First, coronary CTA coronary CTA is injected through the vein contrast agent after the use of high-speed tomography (CT) and then through the computer processing reconstruction of the heart coronary artery vascular imaging of a test method. It can observe coronary artery stenosis or calcification and other lesions, thus showing coronary artery stenosis, good diagnostic accuracy of coronary artery lesions, high sensitivity to calcified lesions, and it monitors coronary artery stenosis with a sensitivity of 75-95%. However, the test requires a higher heart rate, for example, the heart’s beating frequency, rhythm, and whistle movement will interfere with the imaging results. Currently, coronary CTA is mostly used for initial screening of outpatients at high risk of cardiovascular disease. For those who have difficulty in differential diagnosis of symptoms and need to know the degree of coronary artery stenosis initially, doctors often arrange for other tests (e.g., coronary angiography, etc.). Precautions required for this test: 1. Normal rest and dietary contraindications before the test. 2.Requirements during the examination: for the psychological state of patients waiting for the examination process, do a good job of explaining and pacifying, and briefly and simply educate patients on the requirements and matters needing attention during the examination process, in order to eliminate concerns and keep patients in a good state of mind, which is conducive to the smooth progress of the examination. 3, the physician carefully explain to the patient in the examination of the normal reaction (such as contrast agent injected into the body of the patient will produce a generalized feeling of fever, nausea, vomiting), to avoid the patient’s nervousness, resulting in accelerated heart rate, affecting the quality of the examination, or even unsuccessful. Finally, we will talk about the possible results of CTA: 1, the coronary artery is normal, no calcified lesions, no obvious stenosis; 2, there are plaques and stenosis in the coronary artery, and the degree of stenosis is mild stenosis; 3, the degree of stenosis of the coronary artery is more serious, and the degree of stenosis is medium-heavy, and this kind of lesion needs to be further examined by coronary angiography; 4, aneurysm expansion of the coronary arteries, coronary artery entrapment, and so on. Coronary angiography Coronary angiography is an invasive examination, carried out in the catheterization room, the arterial catheter is sent to the aorta at the opening of the coronary artery, injected into the contrast medium, using the machine to observe the multi-angle coronary angiography, to obtain a clear image of the coronary arteries and the flow of blood, you can evaluate the coronary artery vessels, the number of aberrations; evaluation of the coronary artery lesions, the severity of the disease and the range of lesions; evaluation of the coronary artery functionality Coronary artery function can also be evaluated, including the presence or absence of coronary artery spasm and collateral circulation, as well as the evaluation of left heart function. Therefore, coronary angiography is clinically positioned as the “gold standard” for determining the degree of coronary artery stenosis. Possible results of coronary angiography: 1, the inner wall of the coronary artery is smooth, without obvious plaque and stenosis; 2, the inner wall of the coronary artery is rough, plaque formation can be seen, without obvious stenosis; 3, there is stenosis in the coronary artery, but the stenosis is less than 75%, and often do not give interventional intervention, but need to strictly control the cardiovascular risk factors, and long-term adherence to the medication. 4.Coronary artery stenosis is more serious, stenosis is more than 75% or reaches more than 90%, should be early for coronary intervention (stenting). Especially for patients with acute infarction, coronary angiography can clarify the site of coronary occlusion as early as possible, and open the coronary occlusion at an early stage to save the life; for patients with thrombolysis, coronary angiography can determine the effect of thrombolysis at an early stage. Its important clinical diagnostic value is irreplaceable by other examinations such as coronary CT. Depending on the patient’s condition, different examination methods should be selected to provide more targeted treatment in order to achieve better clinical results and reduce the patient’s pain and economic burden at the same time.