Development process of coronary heart disease

At what age did coronary atherosclerosis begin?

Coronary heart disease mostly occurs in middle-aged and elderly people over 40 years old. Therefore, people often have a superficial understanding, as if people began to have atherosclerosis after the age of 40, but it is not. A recent pathophysiological study confirmed that atherosclerosis originated in childhood and gradually worsened with age. This is the first time that China researchers have come to a conclusion through the pathophysiological study of fresh human heart samples. This achievement provides a reliable basis for the prevention and treatment of atherosclerosis in China.

During the Eighth Five-Year Plan period, researchers from Fuwai Cardiovascular Hospital of China Academy of Medical Sciences and other units selected 327 fresh heart samples from residents of fishing areas in Beijing, Nanjing and Ningbo 15 ~ 39 years old, and made a comparative study on pathophysiology. Results The total detection rate of atherosclerotic lesions was 68.3%, which confirmed that Beijing was still a high incidence area of atherosclerosis, and the detection rate of atherosclerotic lesions was 75.8%. Symptoms such as intima thickening, lumen stenosis and vascular aging of coronary artery can appear as early as 20 years old in Beijing, and the low incidence area is about 5 ~ 10 years later, which may be related to diet structure. From the analysis of morphological characteristics, more than 70% of atherosclerotic plaques in Beijing samples are progressive. If not controlled in time, plaque bleeding and mural thrombosis will easily occur, resulting in sudden death of young adults or inducing myocardial infarction. The study of fresh heart samples from a group of high-risk people found that the late stage of atherosclerosis was twice as high as that of ordinary peers, and it was concentrated in 20 ~ 30 years old. This discovery shows that unhealthy lifestyles such as excessive smoking and alcoholism, and mental factors such as anxiety, depression, mania, fear and despair are risk factors for premature atherosclerosis in young people.

From this point of view, the occurrence of atherosclerosis is a very long process, which is the result of many risk factors repeatedly acting on large and medium-sized arteries for a long time. It gets worse with age, so people should establish a healthy lifestyle, strengthen blood vessel protection, pay attention to health accumulation, prevent atherosclerosis, and prevent cardiovascular and cerebrovascular diseases from adolescence.

The degree of coronary atherosclerosis stenosis is divided into several grades, and what is the relationship with coronary heart disease?

Pathologically, the degree of lumen stenosis caused by coronary atherosclerosis is often divided into four grades according to the cross section of the most severe part of stenosis, namely:

Grade I: the lumen stenosis area is below 25%;

Grade ⅱ: lumen stenosis area is 26% ~ 50%;

Grade ⅲ: lumen stenosis area is 51%~ 75%;

Grade ⅳ: lumen stenosis area is 76% ~ 100%.

This simple classification method has been used in the national survey of coronary atherosclerotic lesions, which can basically show the classification of coronary atherosclerotic stenosis and can be used to study the relationship between coronary atherosclerotic stenosis and coronary heart disease. Generally, grade I ~ II atherosclerosis will not cause a significant decrease in coronary blood flow, and has no direct impact on the onset of coronary heart disease except coronary artery spasm. There is a direct relationship between the prescription of stenosis above grade ⅲ and the incidence of coronary heart disease. Pathological examination shows that in patients with coronary heart disease and angina pectoris, the lumen of at least one main branch of coronary artery is obviously narrowed to more than 75% of the cross-sectional area, that is to say, the degree of coronary artery stenosis in most patients is above grade IV. This may be related to the fact that the degree of atherosclerosis in autopsy cases is mostly in the late stage, or it may be the result of the formation of collateral circulation, that is, the main branch of coronary artery is blocked more seriously before angina pectoris occurs. 1989 Beijing fuwai hospital re-examined and analyzed 109 autopsy cases of myocardial infarction. The results showed that the incidence of atherosclerosis in the anterior descending artery was the highest, and the stenosis was the most serious, followed by the right coronary artery trunk and the left coronary artery trunk, and the severe stenosis of the left coronary artery trunk was rare.

What are the inducing factors of coronary heart disease?

With the extensive and in-depth study of coronary heart disease by medical scientists, it shows that the disease is a multi-factor disease, which is caused by many factors acting on different links. These factors are risk factors, or risk factors, mainly including:

(1) Age: This disease is more common in middle-aged and elderly people over 40 years old, and it progresses rapidly after 49 years old. The incidence of myocardial infarction and sudden death in coronary heart disease is proportional to age. In recent years, the incidence of coronary heart disease tends to be younger.

(2) Gender: In the multi-ethnic United States, the mortality rate of male coronary heart disease is significantly higher than that of female. According to the statistical data of 1979, the mortality rate of coronary heart disease in white men aged 35-44 is 5.2 times that of women. In China, the ratio of male to female is about 2:1. However, after menopause, the incidence of coronary heart disease increased significantly due to the obvious decrease of estrogen level and the increase of low density lipoprotein. Some data show that the incidence of coronary heart disease in women after 60 years old is greater than that in men.

(3) Occupation: There are more mental workers than manual workers, and jobs with a sense of urgency are more likely to get sick.

(4) Diet: People who often eat a high-calorie diet and have more animal fat and cholesterol are prone to this disease. At the same time, eating too much is also easy to get this disease. Researchers in Germany, the world's first obese country, believe that "eating too much is because of eating too much". Therefore, to control the incidence of coronary heart disease, in addition to controlling the intake of high-fat diet, we must also pay attention to controlling the intake of food.

(5) Blood lipids: abnormal blood lipids caused by genetic factors, or excessive fat intake, or disorder of lipid metabolism. For example, total cholesterol, triglycerides, low-density lipoprotein, very low-density lipoprotein increase, and high-density lipoprotein decrease, so it is easy to suffer from this disease.

(6) Blood pressure: Elevated blood pressure is an independent risk factor for coronary heart disease. Coronary artery and cerebral artery are the most common hazards of atherosclerosis caused by hypertension. 60% ~ 70% patients with coronary atherosclerosis have high blood pressure, which is four times that of normal people.

(7) Smoking: Smoking is the main risk factor of coronary heart disease. Compared with non-smokers, the incidence and mortality of the disease increased by 2 ~ 6 times, and it was directly proportional to the number of smokers every day.

(8) Obesity: Overweight people (65,438+00% are mild, 20% are moderate and 30% are severely obese) are prone to this disease, especially those who gain weight quickly. However, at present, it is considered that we should pay attention to the research on the method of evaluation weight. Not only the body mass index, but also the thickness of subcutaneous fat. Previous prospective research data showed that the risk of centripetal obesity was high.

(9) Diabetes: It has been recognized that diabetes is easy to cause cardiovascular diseases. Some data show that the incidence of diabetes is twice that of non-diabetic people.

(10) Heredity: If there are people in the family who are prone to the disease when they are young, their close relatives are five times more likely to get sick than those in families without this condition.

Among the above ten factors, hypertension, overweight and high or low cholesterol are the most dangerous factors leading to coronary heart disease and stroke. This is the eighth five-year plan project jointly completed by Fuwai Cardiovascular Hospital of China Academy of Medical Sciences and other units 17, and it is also the result of the first large-scale follow-up survey. The study also shows that the increase of diastolic blood pressure and average body weight leads to the increase of stroke incidence, while the increase of average systolic blood pressure, average body weight and serum cholesterol leads to the increase of coronary heart disease incidence.

What kind of clinical manifestations will you have if you get coronary heart disease?

Due to the differences in age, sex, physical condition, sensitivity, disease progression and collateral circulation, patients with coronary heart disease have various clinical manifestations. Initially, the patient may have no symptoms or discomfort. Occasionally, ischemic changes in ECG are found during physical examination, suggesting that patients have "hidden coronary heart disease" or "asymptomatic myocardial ischemia". Therefore, we should be vigilant, review regularly and give active prevention and treatment. If the coronary atherosclerotic lesion develops further and the degree of lumen stenosis is ≥75%, it can seriously affect the blood supply to myocardium and cause angina pectoris. Most of them show paroxysmal squeezing or contraction pain in the posterior sternum or precordial region, which radiates to the left shoulder, left arm and left finger. However, some angina pectoris occurred outside the chest, or manifested as headache, toothache, sore throat, or upper abdominal pain or discomfort, and some manifested as leg pain alone. It is often necessary to distinguish it from the discomfort caused by the corresponding organs. Some elderly people, especially diabetic patients, only show symptoms such as chest tightness or dyspnea, but have no chest pain, and even have symptoms of acute myocardial infarction without chest pain (painless myocardial infarction). They often go to the hospital with shock as the main clinical manifestation. The most common inducing factors of angina pectoris are physical activity and emotional excitement. Chest pain, such as walking in a hurry, climbing stairs or uphill, is the most typical angina pectoris, and in severe cases, activities such as drying yourself or shaving after bathing can induce angina pectoris. Emotional excitement, such as anger, anxiety, watching fierce sports games, etc. , can cause angina pectoris. However, some studies have shown that the threshold of angina pectoris induced by emotional excitement is often lower than that of exercise or physical labor, so it is speculated that sympathetic nerve-mediated vasoconstriction may be involved at the same time. Full meal is another common factor to induce angina pectoris, which can be induced alone, and a similar situation can be seen after defecation. The inducement and symptoms of most patients are similar, but with the progress of the disease, there is a trend of progressive aggravation. In other patients, angina pectoris has nothing to do with myocardial oxygen consumption, and often occurs in a quiet supine position. For example, when patients have a sudden attack during their sleep at night, they are forced to sit up to relieve themselves, or they can happen during lunch break or lying down during the day. This is supine angina pectoris, indicating that the patient has severe obstructive lesions of multiple coronary arteries and is prone to myocardial infarction. When angina pectoris attacks, some patients are accompanied by dyspnea, palpitation, nausea, sweating, dizziness, pallor and even loss of consciousness. Such as acute myocardial infarction caused by sudden interruption of coronary blood flow, chest pain is more severe and lasts longer, and nitroglycerin is ineffective. There are also patients with coronary heart disease who have no chest pain and only show various types of arrhythmia. The diagnosis of coronary heart disease is speculative unless coronary angiography proves the existence of coronary artery stenosis. Middle-aged and elderly people over 40 years old, if the above situation occurs, should go to the hospital in time, and the doctor will carry out necessary examinations for you to make a clear diagnosis; Patients with coronary heart disease who have been diagnosed should try their best to avoid the occurrence of inducing factors while intervening in risk factors, and regularly go to the hospital for review, and make a reasonable rehabilitation plan under the guidance of doctors.

In addition, more and more patients with sudden cardiac death are caused by coronary heart disease, and statistics in western countries prove that it can be as high as 80% or more. None of these patients are too old. Patients may or may not have a history of heart disease in the past, and often have no symptoms or discomfort before onset, which rarely attracts the attention of patients or doctors. From this point of view, in order to truly understand coronary heart disease, doctors still face many problems to be solved urgently.

How to find coronary heart disease early?

Coronary heart disease is a common and frequently-occurring disease in middle-aged and elderly people. People of this age should seek medical advice in time if they have the following situations in their daily life, so as to find coronary heart disease as soon as possible, so as not to delay their illness.

(1) Chest tightness or constrictive pain in the posterior sternum or precordial region occurs when you are tired or nervous, and it will be radiated to the left shoulder and left upper arm for 3-5 minutes, and then it will be relieved by itself after rest.

(2) Chest tightness, palpitation and shortness of breath during physical activity will be relieved automatically during rest.

(3) Headache, toothache and leg pain related to exercise.

(4) Chest pain and palpitation when having a full meal, catching a cold or watching a thrilling movie.

(5) Those who feel chest tightness and hold their breath when sleeping with a low pillow at night and need a high pillow to feel comfortable; Those who suddenly have chest pain, palpitation and dyspnea when sleeping or lying flat during the day and need to sit up or stand up immediately to relieve them.

(6) Palpitation, chest tightness, shortness of breath or chest pain during sexual life or forced defecation.

(7) Hearing the sound of gongs and drums or other noises around will cause palpitation and chest tightness.

(8) Recurrent irregular pulse, unexplained tachycardia or bradycardia.

What is the inducement of myocardial infarction?

1. Overwork: engaging in incompetent manual labor, especially climbing stairs with heavy load, excessive physical activity, persistent intense fatigue, etc. , can significantly increase the burden on the heart, myocardial oxygen demand suddenly increased, and the coronary artery of patients with coronary heart disease has hardened and narrowed, which can not fully expand, leading to myocardial ischemia in a short time. Ischemia and hypoxia can cause arterial spasm, which in turn aggravates myocardial hypoxia and even leads to acute myocardial infarction.

2. Excitement: Some patients with acute myocardial infarction are induced by strong emotional changes such as excitement, tension and anger. It is reported that there is a state in the United States. On average, every 10 game, there are 8 spectators with acute myocardial infarction.

3. Overeating: Many cases of myocardial infarction occur after overeating. Data at home and abroad show that the incidence of acute myocardial infarction is high on weekends and holidays. After eating a large number of foods containing high fat and calories, the blood lipid concentration suddenly rises, leading to an increase in blood viscosity and platelet aggregation. Thrombosis is formed on the basis of coronary artery stenosis, causing acute myocardial infarction.

4. Cold stimulation: Sudden cold stimulation may induce acute myocardial infarction. This is why doctors always tell patients with coronary heart disease to pay great attention to cold and warmth, and it is also one of the reasons for the high incidence of acute myocardial infarction in winter and spring.

5. Constipation: Constipation is very common in the elderly, but its harmfulness has not attracted enough attention. Clinically, it is not uncommon for the elderly to hold their breath hard when constipation leads to myocardial infarction. Therefore, this problem must be paid enough attention by the elderly to keep the stool unobstructed.