Coronary heart disease, referred to as coronary heart disease, is one of the most common heart diseases, which refers to myocardial dysfunction and/or organic lesions caused by narrowing of the coronary arteries and insufficient blood supply. The World Health Organization classifies coronary heart disease as follows: (1) asymptomatic myocardial ischemia (2) angina pectoris (3) myocardial infarction (4) ischemic cardiomyopathy (5) sudden death Causes and risk factors Coronary heart disease is caused by narrowing of the lumen of the coronary arteries that supply the heart itself due to the formation of atheromatous plaque in the walls of the coronary arteries. It is associated with hypertension, hyperlipidemia, diabetes, smoking and aging, and may also be associated with a sedentary lifestyle, genetics and environmental factors. Symptoms The symptoms vary depending on the location and degree of coronary artery stenosis. Angina pectoris type: manifests as a crushing sensation in the precordial region or behind the sternum, stuffiness, accompanied by significant anxiety, lasting 3 to 5 minutes, often spreading to the left side of the arm, shoulder, jaw, throat, and back. The onset of angina is called exertional angina when there is an increase in myocardial oxygen consumption due to emotion, cold, or a full meal, and is relieved by rest and nitroglycerin. Sometimes angina is atypical and may manifest as tightness of breath, syncope, weakness, belching, especially in the elderly. Myocardial infarction type: It is characterized by persistent severe pressure, stuffiness, or even knife-like pain, located behind the sternum, often spreading to the entire anterior chest, with the left side being the heaviest. Some patients can extend the left arm ulnar side downward, causing the left wrist, palm and fingers tingling sensation, some patients can radiate to the upper limbs, shoulder, neck, jaw, mainly on the left side. The pain is consistent with the previous angina, but lasts longer and is more severe, and is not relieved by rest or nitroglycerin. Sometimes it presents as epigastric pain, which can be easily confused with abdominal disease. It is accompanied by low-grade fever, irritability, excessive and cold sweats, nausea, vomiting, palpitations, dizziness, extreme weakness, dyspnea, and a sense of near death, lasting more than 30 minutes and often several hours. This condition should be seen immediately. Asymptomatic myocardial ischemia type: Many patients have extensive coronary artery obstruction without ever feeling angina, and some even do not feel angina at the time of myocardial infarction. It is only detected by routine physical examination or by coronary angiography because of a positive exercise test. Heart failure and arrhythmia type: Due to extensive lesions and extensive myocardial fibrosis, there are manifestations of heart failure, such as tightness of breath, edema, and weakness, as well as various arrhythmias, which manifest as palpitations. Some patients never have angina pectoris and directly present with heart failure and arrhythmias. Sudden death type: refers to the sudden and unpredictable death due to coronary heart disease Auxiliary examination ECG: ECG is the earliest, most common and basic diagnostic method in the diagnosis of coronary heart disease. However, many patients with coronary artery disease can maintain normal coronary blood flow at rest, without myocardial ischemia, and the ECG can be completely normal, despite the fact that the maximum reserve capacity of coronary arteries has decreased. ECG load test: It mainly includes exercise load test and drug test. Through exercise or other methods, the heart is given a load to induce myocardial ischemia, which in turn confirms the existence of angina pectoris. Ambulatory electrocardiography: A method that allows continuous recording and compilation and analysis of electrocardiographic changes in the heart in active and quiet states over a long period of time. This technique was first used by Holter in 1947 to monitor electrical activity, hence the name Holter Monitoring. Nuclear myocardial imaging: This test can be done when angina cannot be ruled out on ECG based on the medical history. Nuclear myocardial imaging can reveal the ischemic area and clarify the location and extent of ischemia. The detection rate can be increased when combined with exercise testing and re-imaging. Coronary angiography: It is the “gold standard” for the diagnosis of coronary artery disease. It can clarify the presence or absence of coronary artery stenosis, the location, degree and extent of stenosis, and can guide the measures to be taken for further treatment. Ultrasound and intravascular ultrasound: Cardiac ultrasound is one of the most commonly used tests for examining heart morphology, ventricular wall motion, and left ventricular function. It has important diagnostic value for ventricular wall tumors, intra-cardiac thrombus, cardiac rupture, and papillary muscle function. Intravascular ultrasound can clarify the wall morphology and degree of stenosis within the coronary arteries, which is a promising new technology. Myocardial enzymatic examination: It is one of the important tools for the diagnosis and differential diagnosis of acute myocardial infarction. Coronary CT: Despite the availability of coronary angiography as a golden indicator, its widespread clinical application is limited due to its invasive nature. Coronary CT can determine the degree of coronary stenosis to a certain extent without invasion, but due to the limitations of imaging itself, there is also the possibility of false positives and false negatives, which need to be combined with the clinical situation to make a judgment. Prevention Eat a reasonable diet, do not be partial and do not overindulge. It is important to control high cholesterol and high fat foods, as well as to control the total calorie intake and limit weight gain. Have a regular life and avoid excessive stress. Maintain appropriate physical exercise activities to enhance physical fitness. Do not smoke and do not drink alcohol. Actively prevent and treat various chronic diseases: such as hypertension, hyperlipidemia, diabetes, etc. Treatment Medication: including anti-platelet therapy (aspirin, clopidogrel, etc.), β-blockers to reduce myocardial oxygen consumption, angiotensin-converting enzyme inhibitors to improve myocardial remodeling, statins to regulate lipids and stabilize plaque, nitrates to dilate coronary arteries to relieve symptoms, and basic medication for hypertension, hyperlipidemia, hyperglycemia, etc. Interventional therapy: A balloon catheter is placed into the stenotic vessel through a vascular puncture, and the balloon is pressurized and expanded outside the body to open the narrowed vessel wall and restore patency to the diseased vessel. Some dilated lesions require stenting to reduce the incidence of restenosis. Surgical treatment: This involves using one’s own blood vessels (internal mammary artery, radial artery, right gastroretinal artery, saphenous vein) to create a bypass (“bridge”) between the aorta and the diseased coronary artery to allow blood from the aorta to perfuse directly across the stenosis to the distal end of the stenosis, thereby restoring blood supply to the myocardium. Thrombolytic therapy: It is the intravenous injection of thrombolytic drugs to dissolve the thrombus and achieve recanalization of the infarct-related vessels. Others: Chinese herbal medicine, etc. The treatment of coronary heart disease needs to be highly individualized and requires an experienced professional physician to select different treatments according to the patient’s condition.