Transmural myocardial infarction - what is it?
The content of the article:
- The reasons
- Forms of myocardial infarction
- Stages
- Symptoms
- First aid
- Diagnostics
- Treatment
- Rehabilitation
- Prevention
- Forecast
- Video
Transmural myocardial infarction (penetrating myocardial infarction) is a cardiac disease in which necrosis of the entire thickness of the heart muscle occurs against the background of an acute lack of blood supply to the organ, followed by replacement of the necrosis focus with connective tissue.
Myocardial infarction is a serious pathology that belongs to the main causes of death among the population. In the age group from 40 to 50 years, myocardial infarction is more often found in men. After 50 years, the incidence in men and women is comparable. The prognosis for this disease largely depends on the timeliness of the diagnosis of pathology and treatment, but primarily on the type of heart attack and the degree of damage to the heart muscle. About 20% of the total number of sudden deaths occurs in the transmural form of myocardial infarction, which is the most dangerous variant of this disease, since the entire organ wall is affected. It is with this form that medical care often does not have time to be provided. Another 20% of patients die in the first month after suffering a heart attack of this form.
Most often, the anterior wall of the left ventricle of the heart is affected, less often - the right ventricle, atrium. You can see what a macro-preparation looks like in this form of a heart attack in the photo.
The macroscopic preparation shows the affected area of necrosis, spreading to the entire thickness of the heart muscle
The reasons
Myocardial infarction occurs due to acute insufficiency of local blood circulation. In most cases, the cause of the pathology is atherosclerotic lesions of the coronary vessels - blockage of the coronary artery by atherosclerotic plaque. It can also be blood clots and emboli of a different nature (fat particles, air bubbles, etc.) or (less often) spasm.
The development of the disease is facilitated by arterial hypertension, excessive physical activity, carbon monoxide poisoning, frequent stressful situations, unbalanced diet, overweight, age, genetic predisposition, alcohol abuse, smoking (including passive smoking).
Forms of myocardial infarction
By the depth of the necrotic lesion of the heart muscle, a heart attack is:
- transmural - the entire thickness of the myocardium is affected;
- intramural - the focus of necrosis is located in the thickness of the muscle wall;
- subendocardial - the affected area near the endocardium;
- subepicardial - the affected area is adjacent to the epicardium.
A heart attack can be primary, recurrent (occurs no later than 8 weeks after the previous one) and repeated (develops after 8 weeks and later). In addition, myocardial infarction can be complicated and uncomplicated.
The transmural form of the disease, depending on the area of the lesion, is divided into large-focal (extensive) and small-focal infarction.
Depending on localization: infarction of the anterior myocardial wall, lower myocardial wall, other specified localizations, unspecified localization.
Infarction of the anterior (lateral) and lower (posterior) wall of the left ventricle is most often recorded. In this case, acute transmural infarction of the anterior myocardial wall is easier to determine by the electrocardiographic method (ECG) than acute transmural infarction of the lower myocardial wall. With left ventricular myocardial infarction, the likelihood of complications is higher than with other forms of the disease.
Right ventricular infarction in isolation is relatively rare, more often it is accompanied by damage to the posterior wall of the heart. With this form of the disease, cardiogenic shock often develops.
Apex infarction usually has a severe course, can be complicated by rupture of the interventricular septum, aneurysm.
Ventricular septal infarction is often combined with damage to the anterior or posterior wall of the heart. Against the background of this form of the disease, rupture of the septum, ventricular fibrillation, and intravascular thrombosis can occur.
Atrial infarction occurs in 1–17% of cases; this form of pathology is characterized by cardiac arrhythmias.
If it is impossible to determine the form of the disease using an ECG, a diagnosis of an infarction of unspecified localization is made.
Stages
In the clinical picture of the transmural form of a heart attack, the following periods are distinguished:
- Premonitory.
- The most acute (stage of ischemia).
- Acute (necrosis stage).
- Subacute (stage of organization).
- Postinfarction (cicatricial stage).
Symptoms
Depending on the clinical picture, a heart attack can occur in a typical (anginal) or atypical form. The typical, or anginal form, occurs in the overwhelming majority of cases when it comes to transmural lesions of the heart muscle. It manifests itself in intense chest pain, so acute that it can lead to shock (the so-called cardiogenic shock, which is characterized by: sharp pallor and cyanoticity of the skin, a drop in blood pressure, weak pulse, loss of consciousness, dysfunction of all organs).
With the development of cardiogenic shock, there is a high probability of death.
The pain spreads to the left (more often) and / or right (less often) part of the chest, it can radiate to the shoulder, neck, jaw, upper limbs. This pain is called anginal pain. A painful attack is accompanied by severe weakness, cold sweat, dizziness, tachycardia, arrhythmia, and an acute fear of death. Late signs include an increase in body temperature up to 38 ° C, usually occurs on the 2nd day of the disease and lasts about 1 week.
Atypical form of a heart attack can proceed latently, without intense pain (the painless form is typical for patients with diabetes mellitus), pain in the abdomen, fingers of the upper and lower extremities, asthma attacks, unproductive dry cough, edema, headache, dizziness, neurological symptoms can appear …
With the development of the combined form of the disease, typical and atypical signs are combined in the clinical picture.
First aid
If you suspect a myocardial infarction, you need to immediately call an ambulance without waiting for the full clinical picture to unfold - it is impossible to make an accurate diagnosis without an instrumental examination.
Before the arrival of the doctor, the patient should be laid down or seated, placing a pillow or roller from available means under his back, freed from squeezing clothes, provide an influx of fresh air by opening the windows in the room. If the patient has previously been prescribed heart medications, the drug should be given to him. You can also take Nitroglycerin or a sedative such as Corvalol, tincture of valerian, motherwort, etc.
The patient should not be left alone until the ambulance arrives.
Proper first aid treatment for a heart attack can significantly improve the prognosis.
Diagnostics
The main methods for diagnosing a heart attack are ECG, echocardiography (ultrasound of the heart) and a biochemical blood test. These methods make it possible to detect a site of necrosis, to determine the prevalence and duration of a heart attack, localization, and the depth of the lesion. Transmural myocardial infarction on the ECG is manifested by the presence of an abnormal Q wave (QS), which is why it is called Q-positive infarction.
The transmural form of infarction is diagnosed when a pathological Q wave is detected on the electrocardiogram
A biochemical blood test reveals specific markers of heart muscle damage.
The earliest sign found in a general blood test from the first days of the disease is an increase in the number of leukocytes, indicating an inflammatory process. Leukocytosis is observed over the next two weeks. An increase in the rate of erythrocyte sedimentation rate with a decrease in the number of leukocytes is also determined.
Treatment
Treatment of acute transmural myocardial infarction begins in the intensive care unit or resuscitation unit, where measures are taken to maintain basic vital functions, restore blood supply to organs, minimize damage to the heart muscle, and remove toxic decay products of the necrotic focus. After stabilization of the condition, the patient's treatment continues in the cardiology department. Its main tasks are to reduce the area of ischemia, ensure the onset of scarring of the necrosis focus, and prevent the development of possible complications. The patient is shown strict bed rest and complete rest.
Drug therapy includes the appointment of narcotic analgesics (conventional painkillers for transmural infarction are ineffective), tranquilizers, anticoagulants, thrombolytics, vasodilating antispasmodics, antiarrhythmic drugs. In the subacute period, anabolic steroids and vitamin complexes can be used.
In some cases, it may be necessary to remove the occlusion of the vessel by surgery.
Rehabilitation
After suffering a heart attack, the patient needs a long, at least six months, rehabilitation, limitation of physical activity and regular observation by a cardiologist. A postponed heart attack increases the risk of developing a second attack, therefore, it is necessary to strictly follow all the prescriptions of the attending physician.
In the early stages, preventing lung congestion is important. The main goal of physical rehabilitation after a heart attack is the return of full-fledged physical activity. As the patient's condition improves, physical therapy should be started.
Cardiac rehabilitation includes exercise therapy under the supervision of a specialist
Sanatorium treatment is shown.
Prevention
In order to prevent the development of a heart attack, as well as to prevent a second attack, it is recommended to improve the lifestyle: giving up bad habits, correcting excess weight, healthy eating, physical activity, walking in the fresh air, avoiding physical and mental overload. Patients at risk need blood pressure control, preventive examinations by a cardiologist.
Forecast
The prognosis for transmural myocardial infarction is conditionally unfavorable, since changes in the myocardium are irreversible, and damage to the heart muscle throughout its depth leads to a significant decrease in cardiac function. If more than 50% of the heart muscle is damaged, the development of cardiogenic shock, thromboembolism, acute heart failure and a number of other complications, the risk of death is high.
Video
We offer for viewing a video on the topic of the article.
Anna Aksenova Medical journalist About the author
Education: 2004-2007 "First Kiev Medical College" specialty "Laboratory Diagnostics".
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