What Is Myocardial Fibrosis?

Myocardial ischemia refers to a pathological state in which the heart's blood perfusion is reduced, resulting in reduced oxygen supply to the heart, abnormal energy metabolism in the heart muscle, and inability to support normal heart functioning. The energy required for cardiac activity is almost entirely provided by aerobic metabolism, so even when quiet, the myocardial blood oxygen uptake rate is very high (about 70%). Under normal circumstances, the body can regulate itself to promote blood supply and demand Relatively constant to ensure that the heart works properly. When the imbalance of myocardial blood supply and demand is caused for some reason, it constitutes a real myocardial ischemia. Coronary heart disease is the main and most common cause of myocardial ischemia. With the improvement of people's living standards, the prevalence of myocardial ischemia in China is increasing year by year. It has become a common and frequently-occurring disease in middle-aged and elderly people. Some young people between 20 and 30 years old also have myocardial ischemia. which performed.

Basic Information

English name: myocardial ischemia
Visiting department: cardiology
Multiple groups: Middle-aged and elderly

Common causes: Mostly because of coronary atherosclerosis, followed by inflammation, embolism, etc.
Common symptoms: The most common symptom of myocardial ischemia is angina
Contagious: no

Causes of myocardial ischemia

Main reason

There are many reasons that can cause myocardial ischemia. Lower blood pressure, reduced aortic blood supply, and coronary artery obstruction can directly reduce the heart's blood supply; heart valve disease, blood viscosity changes, and myocardial disease can also reduce the heart's blood supply. The most common cause is coronary atherosclerosis, followed by inflammation (rheum, syphilis, Kawasaki disease, and vaso-occlusive vasculitis, etc.), spasm, embolism, connective tissue disease, trauma, and congenital malformations. Species.

2. Risk factors

Epidemiological studies have found that the important risk factors associated with atherosclerosis are hyperlipidemia, hypertension, diabetes, smoking, obesity, low physical activity, and advanced age.

Classification of myocardial ischemia

According to the nomenclature and diagnostic criteria of "ischemic heart disease" published by the World Health Organization, the disease can be divided into the following types:

Angina pectoris

It is the most representative type of myocardial ischemia. It is characterized by paroxysmal and squeezing pain in the thorax. The pain is mainly located in the back of the sternum. It can radiate to the anterior heart area and the left upper limb. It often occurs during labor or emotional excitement. It disappeared after the nitrate preparation. Can be divided into stable, unstable and variant angina.

Myocardial infarction

Myocardial infarction is usually caused by secondary thrombosis on the basis of coronary atherosclerotic lesions. With the advancement of medical technology, the main mortality rate of this disease has decreased in the acute stage, but it is still a serious fatal disease, with a total mortality rate of 30%. It is necessary to pay attention to prevention, especially smoking, obesity, diabetes And lack of manual labor.

3. Ischemic cardiomyopathy

Myocardial ischemia and hypoxia for a long time can cause myocardial cell necrosis and scar formation, and myocardial fibrous tissue hyperplasia. It is characterized by the heart becoming stiff, gradually expanding, and arrhythmia and heart failure occurring. The prognosis is poor, the mortality is high, and the main causes of death are progressive congestive heart failure, myocardial infarction and severe arrhythmia.

4. Sudden death

There are often no life-threatening early manifestations, the main reason being sudden and severe cardiac arrhythmia. Coronary heart disease is the most common underlying heart disease in patients with sudden cardiac death. Therefore, the prevention of sudden cardiac death should be prevented from the root cause of the disease, changing lifestyle and eating habits, reducing the risk of coronary atherosclerosis, and reducing the formation of coronary heart disease. . When there is ischemia, long-term medication should be used to improve myocardial ischemia and prevent the disease from worsening.

Clinical manifestations of myocardial ischemia

1. Trouble in the back of the sternum or in the front of the heart when you are overworked or nervous, or tightening pain, and radiate to the left shoulder and left upper arm for 3 to 5 minutes. After the break, it can relieve itself with heavy sweating.

2. Chest tightness, palpitations, shortness of breath occur during physical activity, and relieved by themselves at rest.

3. Exercise-related sore throat and burning sensation, tightness, toothache, etc.

4. Full meal, cold, chest pain and tightness after drinking.

5. When the sleep pillow is low at night, you feel chest tightness and belching, and you need to feel comfortable in a high-pillow lying position; when you fall asleep or suddenly lie flat during the day, chest pain, palpitations, and difficulty breathing, you need to sit up or stand immediately to relieve it.

6. Pause, chest tightness, shortness of breath, or chest pain during sexual activity or forced bowel movements.

7. Sudden bradycardia, decreased blood pressure, or syncope.

8. Tiredness and lack of energy for no reason at all.

9. Patients without typical symptoms only feel upset stomach, nausea, or toothache, cervical pain and so on.

Myocardial ischemia test

1. Coronary heart disease related examination

In order to detect myocardial ischemia as early as possible, people over 40 years of age should undergo regular physical examinations to understand whether there are risk factors related to coronary heart disease, such as blood lipids, blood pressure, blood glucose, cervical vascular ultrasound, cardiac ultrasound, and electrocardiogram.

ECG is the most commonly used non-invasive test. When a part of the myocardium ischemic, it will affect the normal progress of ventricular repolarization, and can cause ST-T abnormal changes in the ischemic area-related leads. The type of ECG changes in myocardial ischemia depends on the severity, duration, and site of ischemia. In a typical myocardial ischemic attack, the leads facing the ischemic site often show ischemic ST segment depression and / or T wave inversion.

2. Load test inspection

It is an important method for screening high-risk patients for further coronary angiography, coronary interventional therapy, coronary artery bypass surgery, evaluation of drugs and surgical efficacy, and prediction of patient prognosis. Such as active plate electrocardiogram, adenosine-loaded heart echocardiogram, and coronary multi-slice CT. For patients with painless myocardial ischemia, the ischemic challenge test is a very important auxiliary method.

3. Coronary angiography

The obstruction of the main coronary artery and its small branches can be directly observed, which is the most valuable detection method to show coronary atherosclerotic lesions.

Myocardial ischemia treatment

Treatment principle

Because myocardial ischemia is at risk for myocardial infarction and sudden death, early treatment is required when myocardial ischemia is found. Actively prevent the occurrence of atherosclerosis. If it has occurred, it should be actively treated to prevent the development of the disease and strive to reverse it. Those who have experienced complications should be treated in time to prevent deterioration and prolong the patient's life.

2. Drug treatment

Because the mechanism of myocardial ischemia is mainly the imbalance between the supply and demand of myocardial blood (blood oxygen), treating myocardial ischemia is nothing more than increasing myocardial oxygen supply and / or reducing myocardial oxygen consumption, so that myocardial oxygen supply and demand can be reached again. Balanced state.

(1) Antiplatelet drugs prevent thrombosis, prevent coronary and cerebral arterial thromboembolism, and reduce the risk of myocardial infarction, stroke, and cardiovascular death in patients with stable angina pectoris. They should be taken for a long time if there are no contraindications. Commonly used drugs are aspirin. , Clopidogrel, etc.

(2) Beta receptor blockers can slow heart rate, reduce myocardial oxygenation, and prevent sudden death, such as metoprolol or its sustained-release tablets. Beta blockers are the first choice for stable angina pectoris. Combination with nitrates can complement each other. Generally, small doses should be started, and the dose should be adjusted according to treatment response and heart rate changes.

(3) Calcium antagonists can inhibit myocardial contraction and reduce myocardial oxygen consumption; dilate the coronary arteries, relieve coronary spasm, and improve myocardial blood supply. Commonly used drugs are verapamil and nifedipine.

(4) Statins Reduce cholesterol in plasma, stabilize arterial plaques, and prevent plaque from falling off to form blood clots, such as atorvastatin and rosuvastatin.

(5) RAS (renin-angiotensin-aldosterone system) system blocker can prevent ventricular remodeling and improve cardiac function, such as benazepril and valsartan.

(6) Nitrate drugs Dilate coronary arteries and increase blood supply to the heart muscle, such as isosorbide mononitrate.

(7) Thrombolytic drugs Dissolve acutely formed thrombus for acute myocardial infarction.

3. Interventional Therapy

Coronary interventional therapy is widely accepted by patients due to its characteristics of less trauma, quicker recovery, and shorter hospital stay. From the early balloon dilatation, to the era of bare metal stents, to the era of drug-coated stents, it has become an important method for treating this disease. Therefore, for patients with typical or unstable symptoms, unsatisfactory medication, and noninvasive examination suggesting myocardial ischemia, coronary angiography is recommended, and stent placement is necessary.

4. Surgical coronary bypass surgery

Those with complex multivessel disease and unprotected left main disease can choose.

Myocardial ischemia prevention

Diet

Low-salt, low-fat light diet, eat more sweet potatoes, tomatoes, carrots, black fungus and other vegetables, drink some green tea, tea contains a small amount of theophylline, has a certain diuretic effect, and has certain help for patients with myocardial ischemia, There is also vitamin C in tea, which can prevent and cure arteriosclerosis, but it should not be too concentrated.

2. Develop good living habits

Emotions should be stable, avoiding great joy and sorrow, maintaining adequate sleep, regular bowel movements, and not being overworked. Do not watch nervous, scary novels and TV before going to bed, quit smoking and drink less alcohol, avoid excessive physical labor or sudden exertion, and should not exercise after a full meal.

3. Moderate exercise

Can promote the establishment of myocardial collateral circulation, exercise should be based on each person's own physical conditions, hobbies and choices, to do their best.

4. Closely observe changes in the condition

Patients who have been diagnosed with coronary heart disease should pay close attention to their own conditions. If there is any change in the condition, they should seek medical treatment in time. In addition, high-risk groups who are susceptible to coronary heart disease should also have regular physical examinations to detect problems in a timely manner, such as patients with hypertension, diabetes, abdominal obesity, and family history of cardiovascular disease.

5. Preventive drugs

It is mainly used to prevent myocardial infarction or death from coronary heart disease in patients with coronary heart disease. Commonly used drugs include aspirin, beta blockers, calcium antagonists, statins, and angiotensin-converting enzyme inhibitors.