Coronary heart disease is a series of clinical conditions caused by atherosclerosis resulting in narrowing of the coronary artery lumen, resulting in insufficient blood supply to the heart muscle. It includes angina pectoris, myocardial infarction, heart failure, arrhythmia and sudden death. The coronary arteries are located on the surface of the heart and are blood vessels dedicated to supplying blood to the heart’s myocardium itself. It is divided into two left and two right ones. The left side is the left trunk and the right side is the right coronary artery. The left trunk is subdivided into the left anterior descending branch and the left circumflex branch.