Before talking about coronary angiography, let’s first talk about coronary heart disease, coronary heart disease is known as coronary heart disease, of which the most common type is due to atherosclerosis, also known as coronary atherosclerotic heart disease. As we all know, every organ in the human body relies on the heart to supply arterial blood containing oxygen and nutrients to ensure function, and the heart is an important member of each organ. The heart is also relatively “selfish” in that it supplies oxygen and nutrients to “others” while at the same time needing to meet “its own” needs first, so the heart sends out the aorta and then first branches out to supply blood to itself. 2 blood vessels to its own blood supply, these 2 blood vessels is the coronary arteries, respectively, for the left and right coronary arteries, the left coronary artery from the left trunk and then divided into 2 blood vessels called the left anterior descending branch, the left echogenic branch, which is why you hear the most is the heart has 3 blood vessels, in fact, the left 2 in most cases are divided by a trunk. Coronary artery disease is a problem with the blood vessels that supply blood to the heart itself, mainly due to the formation of lipid plaques, resulting in narrowing or occlusion of the coronary arteries, and eventually angina pectoris or myocardial infarction. The purpose of coronary angiography is to check for coronary heart disease and its severity, and is currently the “gold standard” for diagnosing coronary heart disease. Since blood vessels are also “meat” and have little difference in density from the surrounding heart muscle, it is not possible to see if there is any stenosis or occlusion of the coronary arteries under ordinary X-rays, so it is necessary to inject a contrast medium into the coronary arteries to make them visible and to observe the condition of the blood vessels. The procedure of coronary angiography is performed through the radial artery or femoral artery route. Firstly, the puncture point is selected and local anesthesia is applied to the radial artery or femoral artery, and then the arterial sheath is entered after a successful puncture (Fig. 1), and a guidewire is introduced into the arterial sheath to reach the heart, and a contrast catheter is delivered along the guidewire to the heart. to visualize the vessel (Figure 2). According to current standards, coronary artery disease is diagnosed if a stenosis greater than 50% is observed, and stenting is recommended if the stenosis is greater than 75% with evidence of ischemia. Figure 1: Radial artery puncture and tube placement Figure 2: Results of coronary angiography, the black is the vessel and the yellow arrow points to a particularly thin area that looks like it is about to disconnect, which would lead to a diagnosis of coronary artery disease and the need for coronary stenting to improve symptoms of myocardial ischemia.