Myocardial Infarction - What Is It? First Symptoms, Signs And Consequences

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Myocardial infarction: first symptoms, signs and consequences

Content:

• Myocardial infarction mortality statistics
• Causes of myocardial infarction
• The first signs of a heart attack in men and women
• The main symptoms of myocardial infarction
• The consequences of myocardial infarction
• Diagnosis of myocardial infarction
• First aid for a heart attack
• Recovery and rehabilitation after a heart attack
• Prevention of heart attack

Myocardial infarction - what is it?

Myocardial infarction is a focus of ischemic necrosis of the heart muscle, which is formed due to acute disturbance of the coronary circulation. This condition poses a direct threat to life, therefore, it requires urgent hospitalization of a person in the intensive care unit of the cardiology department. If timely assistance is not provided, then the pathological process most often ends in death.

The term was first introduced in 1896 by R. Marie, and the clinical picture of the disease was described in 1892 by VM Kerning.

Statistics indicate that a heart attack between the ages of 40 and 60 occurs in men 3-5 times more often than in women, and is caused by the existing atherosclerosis. From 55 to 60 years old, it is recorded in persons of both sexes with approximately the same frequency. In young and middle-aged women, acute infarction develops less frequently than men, experts attribute this to the fact that female sex hormones delay the development of atherosclerosis. After the end of menopause, the level of estrogen in the female body decreases sharply and they have a heart attack even more often than in men. In addition, the consequences for women from an acute heart attack are more global and often lead to death.

This cardiovascular pathology mainly affects the population living in industrialized countries, in large cities.

If the circulation of the myocardium remains impaired for more than 20 minutes in a row, then this leads to the formation of irreversible changes in the heart muscle, as well as to a pronounced disorder of the functioning of the heart. Some of the muscle cells undergo necrosis, being replaced by connective tissue fibers. As a result, a person who has suffered a heart attack develops a post-infarction scar on the heart. Naturally, this will negatively affect the further work of the body.

Myocardial infarction mortality statistics

Death from myocardial infarction is recorded in 30-35% of cases. Moreover, from 15 to 20% of all sudden deaths fall on this pathology. Statistics indicate that in the United States alone, 140 people die every day from heart attacks.

There is also evidence that 52% of all deaths of a heart attack occur in women and 48% in men.

At the prehospital stage, death occurs in about 20% of cases, another 15% of patients die in the hospital. The maximum mortality rate of patients is recorded in the first two days, therefore it is so important to carry out competent therapeutic actions in this short period. It was experimentally confirmed that if perfusion is restored within 4-6 hours from the onset of the pathological process, then the size of the scar is not so large, the local and general contractility of the left ventricle is significantly improved, the risk of postinfarction complications decreases. The restoration of perfusion within the first 60-120 minutes after the onset of acute infarction has a particularly good effect on the condition of patients.

Causes of myocardial infarction

The etiology of this disease can be very diverse, but in 95% of cases myocardial infarction is a consequence of thrombotic occlusion of arteries that have undergone atherosclerotic changes. In this case, a heart attack is an acute form of cardiac ischemia. The formation of blood clots is facilitated by the high viscosity of blood in patients with ischemia.

In all other cases, a heart attack becomes a complication of other diseases and pathologies, including:

• Malformations of the coronary arteries;
• Blockage of arteries by fragments of a parietal thrombus, a thrombus from a parietal valve, parts of a tumor, vegetation;
• Any inflammation of the vessels responsible for the nutrition of the heart muscle - narrowing of the arteries, their rupture, Buerger's disease, aortic aneurysm, disturbances in the functioning of the vascular endothelium;
• DIC syndrome, accompanied by the formation of a blood clot in the coronary artery. Such factors as a decrease in the volume of circulating blood, infections, poisoning of the body, malignant tumors, thrombocytosis, chronic leukemia, etc., are capable of provoking DIC syndrome;

• Tumor of the heart. A heart attack occurs due to its necrosis, or due to blockage of the coronary artery by parts of a growing neoplasm;
• Extracardiac tumors lead to infarction when they grow and metastasize in the artery;
• Electric shock, mechanical injury, as well as damage to the arteries and the heart during cardiac surgery can provoke a heart attack;
• A heart attack can develop against the background of spasm of the coronary arteries due to the use of drugs (amphetamine, cocaine);
• Hypertension, diabetes mellitus, obesity, alcohol abuse, smoking, nervous and physical stress - all these factors in the presence of heart ischemia can cause a heart attack.

The first signs of a heart attack in men and women

The initial manifestations of a heart attack in men and women are somewhat different. It was found that its symptoms in women are more blurred. Only 43% of patients note the sudden development of pathology; in all other cases, it is preceded by a period of unstable angina pectoris of different lengths with pain at rest.

The first signs of a heart attack in women may resemble the flu or severe fatigue. In this regard, doctors often underestimate the severity of the patient's condition and recommend her home treatment with bed rest. At the same time, 95% of women who suffered a heart attack indicated that their health problems manifested themselves long before the crisis.

On average, the preinfarction period is a month, at which time the following symptoms are observed:

• Up to 70.7% of women noticed increased fatigue. Typically, fatigue does not go away after a night's rest. Patients feel overwhelmed and exhausted, they do not have enough strength to carry out daily activities. Over time, the condition does not improve and turns into constant weakness;
• Sleep problems (up to 47.8%). Women have difficulty falling asleep, often waking up at night;
• Labored breathing. Even with a slight load, the patient develops shortness of breath. After rest, breathing is normalized;
• Pain and discomfort in the chest (29.7%), which resemble the pain that occurs when the muscles of the sternum are stretched. Possible irradiation of pain in the shoulder, upper jaw, arm, neck. Sometimes limbs become numb, tingling occurs in them;
• Probably the development of headache, disorders of the organs of vision;
• Characterized by mood swings, unreasonable anxiety;
• Digestion is impaired, there is heartburn, nausea, and sometimes vomiting;
• The skin is paler than usual, and cold sweats are common.

These statistics of the first signs of a heart attack in women are given by the authors of an article published in the journal Circulation for 2003. The survey involved 515 women who have already suffered a heart attack. They indicate that its first signs are passing: they appear, then they disappear again. Women notice them, but they are in no hurry to see a doctor because of a feeling of embarrassment and fear. They compare their condition with a cold or flu, in which there is also increased fatigue, weakness, weakness.

As for men, the first sign of a heart attack is chest pain. They indicate that they lacked early signs. Of course, this is actually not the case. The body always gives certain signals that something is wrong with it, but men simply ignore them. During the heart attack itself, 43% of women did not experience pain at all, while this pathology is painless in only 10% of men. Breathing problems were mentioned by 57% of the women surveyed.

The main symptoms of myocardial infarction

The main symptoms of myocardial infarction depend on whether it is typical or atypical.

For a typical case, the following clinical picture is characteristic:

• The first period of a heart attack is called "acute". It is characterized by extremely intense pain, which is localized mainly in the chest. They can give to the neck, teeth, left shoulder or collarbone, in the area between the shoulder blades, in the ear;
• The pains are of a different nature. They can be pressing, bursting, sharp. The larger the area of the myocardium is affected, the stronger the pain;
• The attacks of pain are wavy in nature, becoming stronger and weaker. The duration of the attack is different - from half an hour to several hours or even a day. Secondary intake of Nitroglycerin does not relieve pain;
• The patient experiences a strong sense of fear, may be overly agitated. Sometimes attacks of pain, on the contrary, are accompanied by apathy, weakness and shortness of breath;
• The skin turns pale, cold sticky sweat appears;
• Blood pressure rises during an attack and then falls either moderately or sharply. In parallel, the patient develops tachycardia and arrhythmia;
• The gradual extinction of pain characterizes the end of the acute period of the heart attack and the beginning of the acute period. At this time, pain can persist only if the patient develops pericarditis or the peri-infarction zone undergoes severe ischemia;
• The patient's body temperature rises, which is due to the launch of the processes of necrosis and perifocal inflammation. Fever can last up to 10 days or more. The larger the affected area, the higher the body temperature will be, and the longer it will last. In parallel, the symptoms of heart failure and arterial hypotension will increase;
• If the patient survives the acute period of a heart attack, then a subacute period follows with the normalization of body temperature, with the elimination of pain and with an improvement in general well-being. Heart failure symptoms go away.
• In the postinfarction period, all indicators of the patient's health return to a relative norm.

It is worth considering the fact that the symptoms of a heart attack in men are most often clear. The male sex is characterized by the classic development of a heart attack. The predominant symptom is chest pain. In women, a heart attack in the vast majority of cases is blurred. Symptoms are similar to those of the flu or severe fatigue.

Of course, during the acute period of a heart attack, women experience chest pains, but usually they are not as intense as in men. The pain spreads throughout the sternum, not being localized in the region of the heart. Dizziness, cold sweat, nausea, and shortness of breath are characteristic.

As already mentioned, a heart attack can be atypical, the symptoms of which are observed in 70-90% of cases.

Nevertheless, other variants of pathogenesis are not excluded, including:

• Asthmatic variant of the development of an attack. During its onset, shortness of breath and suffocation come to the fore, heart rate increases. The pain is either absent or mild. The frequency of occurrence of the asthmatic variant of myocardial infarction is 10%. Such a course is characteristic either for the elderly, or for those patients who suffer a second attack;
• Gastralgic variant of the development of an attack. The pain is localized in the upper abdomen, accompanied by hiccups, belching, nausea, and repeated vomiting. Bloating is common, and diarrhea can sometimes develop. Pain is given to the back, to the shoulder blades. The incidence of the gastralgic variant of myocardial infarction is 5%. This course of the attack is observed in patients with inferior myocardial infarction;
• Arrhythmic variant of the development of an attack. In this case, a violation of the heartbeat comes to the fore. The pain is not expressed, the person, as a rule, does not pay attention to them. During an attack, weakness is observed, some patients experience shortness of breath. The incidence of the arrhythmic variant of myocardial infarction varies from 1 to 5%;
• Cerebrovascular variant of seizure development. The patient is disoriented in space, experiences dizziness, may faint, sometimes vomiting occurs. Neurological symptoms often blur the clinical picture of a heart attack, and it is possible to determine it only by the results of an ECG. The incidence of cerebrovascular seizure development varies from 5 to 10% and increases with age;
• Low-symptom variant of seizure development. Often, a heart attack is discovered accidentally during an ECG. At the same time, a survey of patients shows that almost 90% of them noted unexplained weakness, deterioration in health and mood, chest pain, shortness of breath. But these symptoms did not make them go to the doctor. The frequency of occurrence of an asymptomatic variant of the development of an attack varies in the range of 0.5-20%. Most often, these attacks occur in people with diabetes.

It should be noted that only the most acute period of a heart attack proceeds atypically, all subsequent periods are characterized by a monotonous clinical picture.

The consequences of myocardial infarction

The consequences of myocardial infarction can often be detected already in the first few hours after its manifestation. They significantly worsen the course of pathology and negatively affect the patient's health.

During the first 3 days, various arrhythmias most often develop: flickering is the most formidable consequence of a heart attack, it often turns into ventricular fibrillation and leads to death. It was found that cardiac conduction disturbances and heart rhythm disturbances occur in 40% of patients in the late period. As for the early period, heart rhythm disturbances are recorded in 100% of patients.

• Left ventricular heart failure is expressed in symptoms of cardiac asthma, congestive wheezing, and possibly the development of pulmonary edema. The most serious consequence of left ventricular failure is cardiogenic shock, which most often leads to death. In this case, the systolic pressure drops below 80 mm Hg. Art., a person loses consciousness, tachycardia and cyanosis are observed. It has been established that acute heart failure in the early period develops in 50% of patients.
• If muscle fibers rupture in the area of necrosis caused by a heart attack, this often leads to the outpouring of blood into the pericardial cavity. This complication is called cardiac tamponade.
• In 2-3% of cases, patients have blockage of the pulmonary artery or systemic circulation by a thrombus. This is the most dangerous complication, which most often leads to the sudden death of a person.
• In 8% of cases, the development of an acute mental disorder is possible.
• Sometimes patients develop acute ulcers of the stomach and intestines. This happens 3-5% of the time.
• Acute heart aneurysm. If it becomes a chronic aneurysm, then most likely the patient will develop heart failure. Chronic heart failure develops in 12-15% of cases.
• A massive infarction is dangerous due to a rupture of the ventricle due to an acute cessation of blood circulation. The risk of ventricular rupture is especially high in the first 10 days after an attack.
• At the end of the acute phase of a heart attack, patients often have fibrin deposition on the walls of the endocardium. This further leads to the formation of a parietal thrombus. Its detached parts can cause embolism of the pulmonary, cerebral, and renal vessels. Thromboembolic complications are recorded in 5-7% of cases.
• A later complication of a heart attack is Dressler's postinfarction syndrome. It is expressed in arthralgia, pleurisy, fever, pericarditis, and eosinophilia. The syndrome develops in 1-3% of cases and is associated with the body's immune response to the formation of a necrotic zone.

Diagnosis of myocardial infarction

Diagnosis of myocardial infarction is based on ECG data, on the collection of anamnesis and the study of indicators of the activity of blood serum enzymes:

Patient interview. The patient's complaints depend on what form of heart attack he has - typical or atypical, as well as on how extensive the area of damage to the heart muscle is. The doctor is obliged to suspect a heart attack when a person has chest pains for half an hour or more.

ECG. On the ECG with a heart attack, a negative T-wave, or a Q-wave, or a pathological QRS complex is formed.

Blood test. Depending on the time after the onset of an attack, an increase in four indicators is found in the blood:

1. For the first 4-6 hours after the manifestation of a painful attack, an increased amount of myoglobin is found in the blood of a person, which is responsible for supplying oxygen to cells.
2. After 8-10 hours from the onset of an attack, the level of creatine phosphokinase in the blood increases by half. This indicator will return to normal only after 48 hours. If there are 3 negative results for creatine phosphokinase, then the heart attack is excluded.
3. After 24-48 hours from the onset of the attack, to confirm the heart attack, a test is performed to determine the enzyme lactate dehydrogenase, the level of which rises precisely during these periods. This indicator will return to normal only after 1-2 weeks.
4. In addition, ESR increases, the level of leukocytes, AsAt and AlAt in the blood.

Echocardiography allows you to determine violations of ventricular contractility, as well as thinning of its wall.

Coronography reveals thrombotic occlusion of the coronary artery, decreased ventricular contractility. In addition, this study provides information regarding the possibility of performing angioplasty or coronary artery bypass grafting.

Troponin test for myocardial infarction

Troponin test for myocardial infarction is a highly specific diagnostic method that allows you to determine the increase in the amount of isoforms of the myocardial troponin protein in the blood. The level of troponin-1 and troponin-T increases significantly 3-4 hours after the attack, which makes it possible to speak with confidence about myocardial infarction. Troponins will remain at high levels in the blood for another two weeks. Therefore, even if a person, for some reason, did not get to a medical institution, the opportunity to determine he had a heart attack still remains.

Modern medicine considers the troponin test as an integral part of the diagnosis of myocardial infarction. Its undoubted advantage is the fact that it allows you to detect even small damage to myocardial muscles.

First aid for a heart attack

First aid for a heart attack should be provided immediately.

It is important to call an ambulance as soon as possible, and before its arrival, observe the following algorithm of actions:

• The patient should take a sitting position. To do this, you can put pillows under his head;
• To ensure air access, it is necessary to unfasten the collar of the shirt, remove from the neck all accessories pulling it (scarves, ties, etc.);
• A person needs to put a tablet of Nitroglycerin under the tongue, or spray one dose of this agent into his mouth, if it is at hand in the form of a spray. If Nitroglycerin is taken for the first time, then the dose should be reduced by half;
• You need to repeat taking Nitroglycerin every 5 minutes. The maximum number of receptions is 3 times;
• In addition to Nitroglycerin, the victim can be given half a tablet of Aspirin and Plavix;
• If the ambulance is delayed, then you can give the patient an injection of Analgin or Baralgin, which will reduce pain.

These are all actions that a person without medical education can perform to help a patient with a heart attack.

Recovery and rehabilitation after a heart attack

Rehabilitation of a patient after a heart attack is a whole range of measures aimed at treating the disease, as well as preventing its complications. Competently built therapy allows you to restore a person's physical activity, correct possible psychological disorders and return him to work.

The patient should gradually restore the lost physical activity. On the first day after a heart attack, strict bed rest is shown with the patient being in the intensive care unit. Doctors are required to constantly monitor all vital signs. If complications of a heart attack do not develop, then on the second day the patient is allowed to sit down and rise in bed. At the same time, you can begin to perform therapeutic exercises under strict monitoring of pulse and pressure.

On the fourth day, the patient is transferred to the common ward, and he can start using the shared toilet. The patient is discharged on days 16-21, before that he is given a test with a dosed physical activity. It allows you to assess the readiness of the body for movement and to assume the risk of developing myocardial ischemia and other delayed complications. If this risk is high, then the timing of patient activation is postponed. Further rehabilitation is carried out in cardiological sanatoriums.

Most people who have had a heart attack require the help of a psychologist or psychiatrist. The fact is that mental disorders are observed in 30% of such patients. These disorders are expressed in a tendency to depression, insomnia and increased anxiety. From 1 to 5% of patients suffer from acute psychoses. At the discretion of the doctor, such patients are prescribed antidepressants, hypnotics and sedatives.

Without fail, the patient is consulted before discharge on the subject of his possible return to work, as well as on which mode of physical activity he should adhere to.

After being discharged from the hospital, patients must follow a certain diet, take medications, and exercise.

Diet. It is important that the meals the patient receives are low in cholesterol and saturated fat. Fresh vegetables (preferably green) and fruits should be included in the menu every day. It is better to replace meat of animals with meat of poultry and fish, and butter and margarine - with olive oil.

Physical exercise. For people in the postinfarction period, special programs have been created that allow you to dose physical activity, contribute to accelerated social and psychological adaptation. Initial training should take place under the strict supervision of doctors, then you can start doing exercises at home. In each case, the amount of exercise is determined individually after the patient has passed the dosed exercise test. Classes on simulators, on bike paths, in the pool are useful. Training should be done at least three times a week.

Taking medicines

All people who have had myocardial infarction should receive medication.

Recommended medicines include:

• Lipid-lowering drugs. So, taking Simvastatin, Atorvastatin, Pravastatin can reduce the risk of a second heart attack. It has been established that statins can reduce the number of deaths from such complications of a heart attack as unstable angina pectoris, cardiosclerosis, exertional angina;
• Antiplatelet agents. Continuous use of Aspirin reduces the risks of developing cardiovascular complications by 25%. Substitutes for aspirin are drugs such as Clopidogrel, Ticlodipine;
• Symptoms of heart failure require the use of ACE inhibitors. The patient is given these drugs during the acute period of a heart attack, then the dose is adjusted;
• Beta-blockers reduce the risk of sudden death after a heart attack by 32%, and also reduce overall mortality by 23%. These can be drugs such as Timolol, Metoprolol, Bisoprolol, etc.

Prevention of heart attack

Prevention of a heart attack is reduced to the following:

• Daily blood pressure monitoring;
• Control of cholesterol and blood sugar levels;
• No bad habits;
• Proper nutrition with the rejection of fried, fatty smoked and canned foods. Reducing the amount of salt consumed;
• Increased physical activity;
• Avoiding stressful situations;
• Timely and adequate treatment of all diseases associated with the heart and blood vessels.

Myocardial infarction is a formidable disease, but maintaining a healthy lifestyle can significantly reduce the risk of developing it.

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The author of the article: Molchanov Sergey Nikolaevich | Cardiologist

Education: Diploma in "Cardiology" received at the PMGMU. I. M. Sechenov (2015). Here I completed my postgraduate studies and received a diploma "Cardiologist".