Myocardial infarction

Myocardial infarction is the death of a portion of the heart muscle during an abrupt imbalance between the myocardium’s need for oxygen and its delivery to the heart.

Myocardial infarction

Table of Contents

Types of myocardial infarction

Myocardial infarction classification:

  • Acute myocardial infarction with the presence of abnormal Q wave.
  • Acute myocardial infarction without a pathological prongQ.
  • Acute subendocardial myocardial infarction.
  • Acute myocardial infarction, unspecified.
  • Recurrent myocardial infarction (from three to 28 days).
  • Repeated myocardial infarction (after the 28th day).

By the size of the hearth:

  • Large focal myocardial infarction.
  • Small focal myocardial infarction.

In relation to the thickness of the heart muscle:

  • Transmural
  • Net transmural

On the localization of myocardial infarction on the electrocardiogram (ECG):

  • I, aVL, V4-V6 – lateral myocardial infarction;
  • V1-V3 – anterior septal myocardial infarction;
  • V4 – apical myocardial infarction;
  • I, Avl, V1-V6 – anterolateral myocardial infarction;
  • II, III, aVF – lower myocardial infarction.

Stages of myocardial infarction:

  • The sharpest stage. Duration up to 6 hours. Focal dystrophy and ischemia is observed.
  • Acute stage. Duration from 6 hours to a week. The processes of melting the hearth prevail.
  • Subacute stage. Duration from three weeks to two months.
  • Chronic stage. Duration is more than two months.

Atypical forms of myocardial infarction:

  • Asthmatic option.
  • Abdominal option.
  • Arrhythmic option.
  • Cerebrovascular variant.
  • Little or asymptomatic option.


Causes of myocardial infarction

  • Clogged thrombus or embolus of the heart (coronary, coronary) arteries.
  • Atherosclerotic vascular process.
  • Spasm of the coronary arteries.
  • The separation of the walls of the aorta or coronary vessels.
  • Anomalies of the structure of the heart arteries.


Symptoms of myocardial infarction

Patients complain of pain in the chest, behind the sternum, which lasts more than 25-30 minutes, and when taking nitroglycerin under the tongue – the pain is not eliminated.

The pain may radiate (give) in the back, in the left hand, in the stomach, in the neck or in the lower jaw.

Those who give pain to a patient or a doctor can perceive it as a pathology of another organ, therefore it is very important to tell about your painful sensations from the very beginning, so that the cardiologist has a complete understanding of the disease that has begun.

On examination of the patient , the cardiologist may observe the presence of dyspnea at rest, excessive sweating of the patient, as well as a decrease or increase in blood pressure (hypotension or hypertension) and heart rhythm disturbances.

The patient may complain of nausea or dizziness, and there may be complaints about an atypical clinical picture of myocardial infarction, in which there is abdominal pain and upset stool (diarrhea, diarrhea).

When listening to the heart, the muffledness of the first heart tone will be noted, as well as a soft systolic murmur, sometimes a friction noise of the leaves of the pericardium is heard after three days (fibrin deposition).

If you do not start diagnosing and treating the patient, then complications may develop in the form of heart failure, cardiogenic shock, pulmonary edema, left ventricular heart wall rupture, mitral valve insufficiency, cardiac rhythm or conduction disorder, thromboembolism, ventricular wall aneurysm, pericarditis (syndrome Dressler) and even death.


Diagnosis of myocardial infarction

For complete information about the diagnosis, treatment, and most importantly – about the prevention of myocardial infarction, you need to make an appointment with a physician or cardiologist. Consultation of the doctor will help determine the further tactics of examination and treatment.

Diagnosis of myocardial infarction begins with the interpretation of the patient’s complaints, external examination, measurement of heart rate, blood pressure and listening to the heart.

Electrocardiography (ECG) remains the main method for diagnosing heart disease , it remains the very first and unconditional study if the patient has complaints of pain in the heart, and is mandatory. Conducts an ECG doctor functional diagnostics. According to the ECG, you can determine the position of the axis of the heart, the regularity and frequency of the heartbeat, determine the source of excitation and conductivity in the heart. This will provide an opportunity to clarify or make a diagnosis, prescribe the appropriate treatment.

Laboratory diagnosis of myocardial infarction is based on standard methods for the study of clinical blood analysis (neutrophilic leukocytosis, increases the erythrocyte sedimentation rate). A biochemical blood test will help detect in its serum the presence of special enzymes that are narrowly specific and appear only in myocardial infarction: troponin I, troponin T. There are also non-specific serum enzymes that can appear in other diseases of organs and systems: CK, MF- KFK, LDH, AST, ALT, myoglobin.

Treatment of myocardial infarction

  • First of all, it is necessary to stop the pain, regardless of its manifestation. Nitroglycerin is used sublingually (under the tongue), narcotic analgesics (intravenous morphine), you can also use a combination of nitroglycerin and beta-blockers (intravenously).
  • A constant supply of oxygen is needed to combat hypoxia and ischemia of the focus in myocardial infarction.
  • Antiplatelet therapy is required for the appointment to improve the rheological properties of blood, and to prevent blood clots.
  • Thrombolytic therapy is designed to dissolve the already formed blood clots in the vascular system of the body. But it is especially effective with the introduction of drugs (streptokinase) no later than 1 hour after the onset of an attack.
  • Surgical treatment is presented in the form of transluminal angioplasty.

Prevention of myocardial infarction

  • Active lifestyle.
  • Rational nutrition, with the restriction of animal fats and with a lot of vegetables and fruits.
  • Compliance with the regime of work and rest.
  • To carry out continuous monitoring of body weight.
  • Timely treatment of coronary heart disease (stenting) and maintaining normal blood pressure numbers.
  • Avoid psycho-emotional experiences.

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