The sinus node, the basis of the electrical activity of the heart, is the physiological pacing point that controls the electrical activity of the heart and determines the rhythm of its contraction. The sinoatrial node, located in the lateral right atrium, rhythmically sends impulses that transmit electrical signals through the heart’s conduction system to cardiac muscle cells, causing regular, sequential contraction and diastole of the atrial and ventricular muscles.
The “pump” function of the heart is based on the periodic contraction and diastole of the myocardium, which drives the blood in the circulatory system (blood vessels + tissue microcirculation) to flow in a certain direction, transporting oxygen, nutrients, hormones, etc. to various organs and tissues of the body, and transporting metabolites and carbon dioxide from tissues and organs to the corresponding organs for processing or excretion. The metabolites and carbon dioxide from the tissues and organs are transported to the corresponding organs for processing or excretion. When the myocardium contracts, the heart chambers become smaller and the pressure rises, pumping blood out of the heart chambers; when the myocardium diastolic, the heart chambers become larger and the pressure decreases, promoting the return of blood to the heart chambers. The valves between the atria and ventricles – the atrioventricular valve (mitral and tricuspid valves) and the aortic and pulmonary valves – act as one-way valves to ensure that the heart performs its “pumping” function with blood flowing in a certain direction, over and over again, without flowing in the opposite direction (“regurgitation”). “regurgitation”).
The whole process of diastole and contraction of the atria and ventricles, and the opening and closing of the heart valves, is highly coordinated and occurs in a certain sequence, under precise regulation. During atrial diastole, blood flows back into the atrium from the veins (superior and inferior vena cava and pulmonary veins); while the atrium contracts, the ventricle diastole, the atrioventricular valve (mitral and tricuspid valves) opens and blood flows into the ventricle through the atrioventricular valve opening; during ventricular contraction, the atrioventricular valve closes and the semilunar valve (aortic valve and pulmonary valve) opens, blood shoots from the ventricle into the aorta and pulmonary artery and enters the body and pulmonary circulation respectively.
Effective control measures for common heart diseases.
l. Discomfort such as palpitations, fatigue, shortness of breath or a sense of dyspnea during physical activity.
2.Sudden onset of chest pain, chest tightness or a feeling of pressure during exertion or stress.
3.Pain in the left chest accompanied by sweating or pain radiating to the shoulder, arm and neck.
4.Pulse is too fast, too slow, short or irregular.
5.Suddenly wake up during sleep or dream, feel palpitations, chest tightness, and breathlessness.
6.Feeling difficulty in breathing, chest tightness or chest pain during sexual life.
7.Feeling palpitations, chest tightness or chest pain when having a full meal, cold, smoking, watching a tense movie or TV.
8, in public places, often feel chest tightness, breathlessness and insufficient air.
9.When going upstairs, palpitations and shortness of breath occur more easily than before or than others.
10.Sudden palpitations, dizziness, blackness in front of the eyes and the feeling of falling when at rest.
11.Children are less active than their peers, with palpitations, shortness of breath, weakness, and blue lips during activities.
12.Palpitations and fatigue with light work or feeling of shortness of breath when walking slightly fast after a cold.
L3, sudden chest discomfort, fainting on the floor or a sense of “near death”.
L4, when sleeping at night with a low pillow, feel difficulty in breathing and need to sleep with a high pillow.
15. Swelling of the lower extremities, hypertrophy and deformation of the ends of the fingers or toes.
l6. Abnormal colors such as cyanosis and dark red appear on the face, mouth, lips and nails.
l7. Abnormal rhythm of heartbeat, missed beats, stopping beats or palpitations under resting state.
L8. Tremor when touching the heart area on the front chest wall with the palm.
l9. Palpitations, dizziness, shortness of breath or swelling during pregnancy.
20, Frequent radiating pain in the left shoulder.
Overview of common heart diseases.
1, angina pectoris is a clinical syndrome caused by insufficient coronary artery blood supply and acute, temporary ischemia and hypoxia of the myocardium. It is characterized by paroxysmal anterior chest crushing pain sensation, may be accompanied by other symptoms, pain is mainly located in the posterior sternum, can be radiated to the precordial area and the left upper limb, often occurs during labor or emotional excitement, lasting several minutes, disappear after rest or with nitrate preparations. The disease is mostly seen in men, and most patients are over 40 years old. Exertion, emotional excitement, satiety, cold, rainy weather, acute circulatory failure, etc. are common triggers.
2, arrhythmia arrhythmia refers to abnormal impulse generation, abnormal conduction and combined abnormal impulse generation and conduction caused by any abnormality of sinus node pacing frequency, impulse conduction process or abnormal discharge of atrial and ventricular cells. In addition, premature ventricular contractions caused by abnormal autoregulation may result in sustained ventricular tachycardia by a foldback mechanism. The diagnosis of the nature of the arrhythmia mostly depends on the electrocardiogram, but a significant proportion of patients can make a preliminary diagnosis based on history and physical signs.
3, myocardial infarction Myocardial infarction is a fatal extreme form of coronary heart disease due to occlusion of coronary arteries and interruption of blood flow, resulting in local necrosis of part of the myocardium due to severe and persistent ischemia. Clinically, there is severe and more persistent retrosternal pain, fever, leukocytosis, accelerated erythrocyte sedimentation rate, increased serum cardiac enzyme activity and progressive electrocardiographic changes, and arrhythmias, shock or heart failure may occur.
The size, extent and severity of myocardial infarction depend mainly on the site, degree and speed of coronary artery occlusion and the communication of collateral circulation. Occlusion of the anterior descending branch of the left coronary artery is most common and can cause infarction of the anterior wall, apical region, inferior lateral wall, anterior septum and anterior internal papillary muscle of the left ventricle; occlusion of the gyral branch of the left coronary artery can cause infarction of the high lateral wall of the left ventricle, diaphragmatic surface and left atrium, and can involve the atrioventricular node; obstruction of the left coronary artery can cause infarction of the diaphragmatic surface of the left ventricle, posterior septum and right ventricle, and can involve the sinus node and atrioventricular node. Infarction of the right ventricle and left and right atria is less common. Left ventricular subendocardial myocardial infarction is often the result of severe lesions in all three coronary arteries. Occlusion of the main coronary artery causes extensive infarction of the left ventricle.
The diagnosis of the disease is not difficult based on the typical clinical presentation, characteristic electrocardiographic changes and laboratory findings. The diagnosis is more difficult in patients without pain. Once the diagnosis is clear, the main treatment tools are currently: percutaneous intracoronary balloon sphincter angioplasty, intracoronary stenting, coronary artery bypass grafting and other interventional procedures.
Lifestyle guidelines to ensure cardiovascular health.
I. Weight control. A 10% increase in body weight increases the risk of coronary heart disease by 38%; a 20% increase in body weight increases the risk of coronary heart disease by 86%, and the prevalence of coronary heart disease in hypertensive patients with diabetes is 1 times higher than in hypertensive patients without diabetes.
Second, quit smoking. Nicotine in tobacco can make the heart beat faster, blood pressure (excessive smoking can make blood pressure drop), increased oxygen consumption of the heart, vascular spasm, abnormal blood flow and increased adhesion of platelets. These adverse effects, the incidence of coronary heart disease in men aged 30-49 years who smoke is three times higher than in nonsmokers, and smoking is also an important cause of angina attacks and sudden death.
Third, limit alcohol. Excessive ethanol intake can reduce the contractility of the heart muscle. For people with heart disease, alcohol abuse will not only increase the burden on the heart, and even lead to arrhythmias, and affect fat metabolism, and promote the formation of atherosclerosis.
Fourth, improve the living environment. Severe pollution and noise intensity of the place may induce heart disease. Therefore, improve the living environment, expand the green area, reduce the noise and try to stay away from all kinds of pollution.
Five, avoid crowding. Whether it is viral myocarditis, dilated cardiomyopathy, or coronary heart disease, wind heart disease, are related to viral infections, even heart failure is often caused by acute exacerbation of upper respiratory tract infection. Therefore, attention should be paid to avoid crowded places, especially in the flu season, to reduce the chance of infection.
Sixth, reasonable diet. Hyperlipidemia, unbalanced diet, diabetes and obesity are all related to dietary nutrition, so from the point of view of heart disease prevention and treatment, nutritional factors are very important. In principle, we should achieve “three low”, namely: low calorie, low fat, low cholesterol, specific measures should be in line with the following requirements: l. Daily cholesterol intake should not be less than 1.5 mg.
l. Daily cholesterol intake should not exceed 300 mg.
2, fat intake does not exceed 30% of total calories.
3, eat less or no sucrose, glucose content of high food.
4.Eat more foods rich in vitamin C, such as fruits, fresh vegetables, etc.
5, eat less food containing saturated fatty acids and high cholesterol, such as fatty meat, egg yolk, animal oil, animal offal, etc.
6, diet should be high in potassium and low in sodium, encourage the consumption of soy products and drink tea.
7.Eat regularly, try to avoid excessive hunger or overeating.
8, appropriate intake of fiber foods (including cereal starch) to keep the bowels open.
9.At least one meal a day with black fungus, which has the health benefits of regulating blood lipids, lowering blood sugar and regulating immunity.
10. Drink a moderate amount of water at night before going to bed and try not to eat.
Seven, reasonable exercise actively participate in the appropriate amount of sports. Maintain regular and appropriate exercise is conducive to enhancing heart function and promoting normal body metabolism, especially to promote fat metabolism and prevent the occurrence of atherosclerosis has an important role. For patients with heart disease, according to the function of the heart and physical strength, engaging in an appropriate amount of physical activity can help improve blood circulation, enhance resistance, improve the function of all organs of the body, and prevent thrombosis. However, it is necessary to avoid overly strenuous activities, and the amount of exercise should be gradually increased, in order not to cause discomfort symptoms.
Regular moderate exercise can promote the expansion, extension and branching of the tiny blood vessels in the heart, improve the oxygen supply to the heart muscle and improve the body’s lipid metabolism. Exercise also helps to improve myocardial metabolism, improve the working capacity of the heart muscle and the metabolic function of the heart. In addition, it also improves the fibrinolytic activity of the blood, preventing excessive blood viscosity, which is important for preventing blood clots and delaying the formation of atherosclerosis.
Heart-healthy exercise.
1, walking: walking can make myocardial contraction, peripheral vascular expansion, with enhanced cardiac function, lower blood pressure, the effect of preventing coronary heart disease. For people who participate in sports will cause angina, can improve the condition. Each walk can be insisted on 20 minutes to 1 hour, 1 to 2 times a day, or walk 800-2000 meters a day. Those whose physical condition allows can appropriately increase the walking speed.
2, jogging: jogging or running in place can also improve heart function. As for the jogging distance and in situ running time should be based on the specific circumstances of each person, do not have to be forced.
3, taijiquan: for hypertension, heart disease, etc. have a better prevention and treatment effect. Generally speaking, patients with good physical strength can practice old-style taijiquan, and those with poor physical strength can practice simplified taijiquan. If you can’t play a full set, you can play half a set, and those who are weak and have poor memory can only practice individual movements and practice in sections, not in a row.
Precautions in physical exercise.
l, anyone, if after 10 minutes of exercise, the number of heartbeats per minute is still more than 100, should not increase the amount of exercise, should be appropriate to reduce the amount of exercise according to the situation.
2, the amount of exercise should be small to large, from short to long time, gradually.
3, meal and exercise interval of at least 1 hour or more.
4, the most suitable temperature for exercise is 4 ℃ -30 ℃.
5, exercise if dizziness, headache, panic, nausea, vomiting and other uncomfortable symptoms, should immediately stop. Cardiovascular disease patients, should not exercise early in the morning, for three reasons.
(1) the human body in the morning hours sympathetic nerve activity is high, and the ensuing increase in bioelectrical instability, easily lead to arrhythmia, ventricular fibrillation may occur, causing sudden death.
(2) 6:00 a.m. to 9:00 a.m. is the most dangerous time for coronary heart disease and cerebral hemorrhage attacks, with an incidence rate more than three times higher than 11:00 a.m.
(3) Human arterial pressure is higher in the morning, increasing the possibility of atherosclerotic plaque rupture, leading to the onset of acute coronary syndrome.
Eight, regular life to develop a healthy lifestyle habits. Live a regular life, have a happy mood, avoid emotional excitement and overexertion. Once a person’s emotions are tense and excited, it will make the sympathetic nerve excitement, catecholamines increase, resulting in a faster heartbeat, higher blood pressure, myocardial oxygen consumption also increased significantly, aggravating the condition of patients with coronary heart disease and heart failure. More seriously, these changes can sometimes lead to lethal arrhythmias, causing cardiac arrest.
As the ancients say, “Harmonize happiness and anger and live in peace, regulate yin and yang and adjust the rigid and soft” is a good motto to regulate the body and mind.