Myocardial infarction - Causes, symptoms and treatment. MF.

Myocardial infarction is an emergency, most commonly caused by coronary artery thrombosis. The risk of death is especially great in the first 2 hours from the beginning and very quickly decreases when the patient enters the intensive care unit and is dissolving a thrombus called thrombolysis or coronary angioplasty. Isolate myocardial infarction with a pathological Q tooth and without it. As a rule, the area and depth of the lesion is greater in the first case, and the risk of re-development of the infarct in the second. Therefore, the long-term prognosis is approximately the same.

Causes of myocardial infarction

Most often the infarct affects people suffering from a lack of motor activity against the background of psycho-emotional overload. But he can also defeat people with good physical training, even young ones. The main causes contributing to the occurrence of myocardial infarction are: overeating, malnutrition, excess in the diet of animal fats, inadequate motor activity, hypertension, bad habits. The likelihood of developing a heart attack in people leading a sedentary lifestyle is several times greater than that of physically active ones.

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The heart is a muscular bag that pumps a pump through itself. But the heart muscle itself is supplied with oxygen through the blood vessels that approach it from the outside. And now, as a result of various reasons, some of these vessels are affected by atherosclerosis and can not already pass enough blood. There is coronary heart disease. With myocardial infarction, the blood supply of a part of the heart muscle stops suddenly and completely because of a complete blockage of the coronary artery. Usually this leads to the development of a thrombus on an atherosclerotic plaque, less often - a spasm of the coronary artery. A segment of the heart muscle, devoid of nutrition, perishes. In Latin, dead tissue is a heart attack.

Symptoms of myocardial infarction

The most common manifestation of myocardial infarction is chest pain. The pain "gives" on the inner surface of the left hand, producing sensations of tingling in the left arm, wrist, fingers. Other possible areas of irradiation are the shoulder girdle, neck, jaw, interscapular space, also predominantly on the left. Thus, both localization and irradiation of pain does not differ from an attack of angina pectoris.

Pain with myocardial infarction is very strong, perceived as a dagger, tearing, burning, "a stake in the chest."Sometimes this feeling is so unbearable that it makes you scream. Just like with angina pectoris, not pain, but discomfort in the chest can arise: a feeling of strong contraction, compression, a sense of heaviness "tightened the hoop, squeezed into the vise, crushed by a heavy plate."Some people have only dull pain, numbness of the wrists in combination with severe and prolonged chest pain or discomfort in the chest.

The onset of anginal pain in myocardial infarction is sudden, often at night or in the pre-morning hours. Painful sensations develop wavy, periodically decrease, but do not stop completely. With each new wave of pain or discomfort in the chest strengthened, quickly reach a maximum, and then weaken.

A pain or chest discomfort lasts more than 30 minutes, sometimes for hours. It is important to remember that for the formation of myocardial infarction, the duration of angina pain is longer than 15 minutes. Another important distinguishing feature of myocardial infarction is the absence of reduction or cessation of pain in resting state or with the intake of nitroglycerin( even repeated).

Angina or myocardial infarction

The origin of pain with angina and myocardial infarction is the same. The main differences in pain in myocardial infarction are:

severe pain intensity;
duration is more than 15 minutes;
pain does not stop after taking nitroglycerin.

Atypical forms of myocardial infarction

In addition to the typical, characteristic for the infarction of sharp tearing pain behind the sternum, several other forms of infarction are identified, which can be masked for other diseases of internal organs or not manifest themselves in any way. Such forms are called atypical. Let's get into them.

Gastritic variant of myocardial infarction. Appears as a pronounced pain in the epigastric region and resembles an exacerbation of gastritis. Often with palpation, i.e.abdominal palpation, pain and tenderness of the muscles of the anterior abdominal wall. As a rule, in this form, the lower divisions of the left ventricle myocardium, adjacent to the diaphragm, are affected.

Asthmatic variant of myocardial infarction. This atypical type of infarction is very similar to an attack of bronchial asthma. It is manifested by an uncomfortable dry cough, a feeling of stuffiness in the chest.

A painless variant of a heart attack. It is manifested by an inability to sleep or mood, a sense of undefined chest discomfort( "heartache") combined with a marked sweating. Typically, this option is characteristic in the elderly and senile age, especially in diabetes mellitus. This variant of the onset of myocardial infarction is unfavorable, since the disease proceeds more severely.

Factors of myocardial infarction development

Myocardial infarction risk factors are:

age, the older a person becomes, the risk of a heart attack increases.
previously suffered myocardial infarction, especially small-focal, i.e.non-Q generatrix.
diabetes is a risk factor for the development of myocardial infarction, becausean increased level has an additional detrimental effect on the blood vessels and hemoglobin, worsening its oxygen transport function.
smoking, risk of myocardial infarction when smoking, both active and passive, simply inhaling tobacco smoke from a smoking person, increases by 3 and 1.5 times, respectively. Moreover, this factor is so "corrosive" that it persists for the next 3 years after the patient has given up smoking.
arterial hypertension, increasing blood pressure above 139 and 89.
high cholesterol, promotes the development of atherosclerotic plaques on the walls of arteries, including coronary arteries.
obesity or overweight helps increase blood cholestrin and as a result, blood supply to the heart worsens.

Prevention of myocardial infarction

Methods of preventing myocardial infarction are similar to the prevention of coronary heart disease.

Probability of complication development of myocardial infarction

Myocardial infarction is dangerous in many respects, its unpredictability and complications. The development of complications of myocardial infarction depends on several important factors:

the magnitude of damage to the heart muscle, the greater the area affected by the myocardium, the greater the complication;
localization of the zone of myocardial damage( anterior, posterior, lateral wall of the left ventricle, etc.), in most cases, there is a myocardial infarction in the pereborodochnoy area of the left ventricle with the capture of the tip. Less often, in the area of the lower and posterior wall of the
, the time of restoration of blood flow in the affected heart muscle plays a very important role, the earlier the medical help is provided, the less the damage zone will be.

Complications of myocardial infarction

Complications of myocardial infarction mainly occur with extensive and deep( transmural) damage to the heart muscle. It is known that a heart attack is a necrosis( necrosis) of a certain zone of the myocardium. In this case, muscle tissue, with all its inherent properties( contractility, excitability, conductivity, etc.), is transformed into a connective tissue that can only perform the role of a "skeleton".As a result, the thickness of the heart wall decreases, and the dimensions of the cavity of the left ventricle of the heart grow, which is accompanied by a decrease in its contractility.

The main complications of myocardial infarction are:

arrhythmia is the most common complication of myocardial infarction. The greatest danger is represented by ventricular tachycardia( the kind of arrhythmia in which the role of the pacemaker takes on the ventricles of the heart) and ventricular fibrillation( chaotic ventricular wall shrinkage).However, it is necessary to remember, any hemodynamically significant arrhythmia requires treatment.
heart failure( decreased cardiac contractility) occurs with myocardial infarction quite often. Reduction of the contractile function occurs in proportion to the size of the infarction.
arterial hypertension due to increased oxygen demand in the heart and tension in the wall of the left ventricle leads to an increase in the zone of the infarction, and to its stretching.
mechanical complications( heart aneurysm, rupture of interventricular septum) usually develop in the first week of myocardial infarction and clinically manifest as sudden deterioration of hemodynamics. Mortality in such patients is high, and often only an urgent operation can save their lives.
recurrent( recurring) pain syndrome occurs in about 1/3 of patients with myocardial infarction , thrombus dissolution does not affect its prevalence.
Dressler's syndrome is a post-infarction symptom complex, manifested by inflammation of the heart bag, lung bags and inflammatory changes in the lungs themselves. The emergence of this syndrome is associated with the formation of antibodies.
Any of these complications can be fatal.

Diagnosis of acute myocardial infarction

Acute myocardial infarction is diagnosed on the basis of 3 main criteria:

characteristic clinical picture - with myocardial infarction there is a strong, often tearing, pain in the region of the heart or behind the breastbone, giving to the left shoulder blade, arm, lower jaw. The pain lasts more than 30 minutes, while taking nitroglycerin does not completely go away and only does not decrease for a long time. There is a feeling of lack of air, cold sweat, severe weakness, lowering of blood pressure, nausea, vomiting, fear can appear. Prolonged pain in the heart, which lasts more than 20-30 minutes and does not pass after taking nitroglycerin, may be a sign of the development of myocardial infarction. Address in the ambulance.
characteristic changes in the electrocardiogram( signs of damage to certain areas of the heart muscle).Usually, this is the spacing of the Q teeth and the rise of the ST segments in the leads concerned.
characteristic changes in laboratory parameters( increase in blood levels of cardiospecific markers of cardiac muscle cell damage - cardiomyocytes).

Emergency care for myocardial infarction

An ambulance should be called if this is the first time in a life attack of angina, and if:

chest pain or its equivalents intensifies or lasts more than 5 minutes, especially if all this is accompanied by a worsening of breathing, weakness, vomiting;
chest pain did not stop or intensified within 5 minutes after resorption of 1 tablet of nitroglycerin.

Help before the arrival of the "First Aid" for myocardial infarction

What should I do if I suspect a heart attack? There are simple rules that will help you save the life of another person:

patient lay, raise the head, re-give a tablet of nitroglycerin under the tongue, and in the grinded form( chew) 1 tablet of aspirin;
additionally take 1 tablet of analgin or baralgina, 60 drops of corvalol or valocardin, 2 tablets of panangin or potassium orotate, put a yellow card on the heart area;
urgently call an ambulance team( "03").

Each

should be reanimated. The chances of the patient to survive are higher the earlier resuscitation measures have been started( they should be started no later than one minute after the onset of a cardiac catastrophe).Rules for the main resuscitation:

If the patient does not respond to external stimuli, immediately go to point 1 of this Regulation.

Ask someone, for example, neighbors to call an ambulance.

Properly pack the reanimated, ensuring airway patency. For this:

patient must be laid on a flat solid surface and the maximum to throw back his head.
to improve the patency of the airways from the mouth, you need to remove removable dentures or other foreign bodies. In case of vomiting, turn the patient's head to the side, and remove the contents from the mouth and pharynx with a tampon( or improvised means).

Check for self-contained breathing.
If there is no independent breath, start artificial ventilation. The patient should lie in the previously described posture on his back with a head thrown back sharply. The pose can be provided by placing under the shoulders of the roller. You can hold your head with your hands. The lower jaw must be pushed forward. The assisting person takes a deep breath, opens his mouth, quickly brings it closer to the patient's mouth and, pressing his lips tightly to his mouth, makes a deep exhale, i.e.as if blowing air into his lungs and inflating them. To the air does not go through the nose reanimiruemogo, pinch his nose with your fingers. Then the relief man leans back and takes a deep breath again. During this time, the chest of the patient falls down - there is a passive exhalation. Then the caretaker again blows air into the patient's mouth. For hygienic reasons, the patient's face can be covered with a handkerchief before blowing air.
If there is no pulse on the carotid artery, artificial ventilation of the lungs must necessarily be combined with indirect heart massage. For an indirect massage, place your hands one on top of the other so that the base of the palm resting on the sternum is strictly on the median line and 2 fingers above the xiphoid process. Without bending hands and using your own body weight, for 4-5 cm smoothly move the sternum to the spine. At this displacement, compression( compression) of the chest occurs. Massage so that the duration of the compression is equal to the interval between them. The frequency of compression should be about 80 per minute. In pauses, leave your hands on the sternum of the patient. If you are carrying out intensive care alone, after 15 compressions of the thorax, make two air inlets in succession. Then, repeat an indirect massage in combination with artificial ventilation.
Do not forget to constantly monitor the effectiveness of your resuscitation. Resuscitation is effective if the patient has pink skin and mucous membranes, pupils have narrowed and a response to light has appeared, spontaneous breathing has resumed or improved, a pulse appeared on the carotid artery.
Continue resuscitation before the ambulance arrives.

Treatment of myocardial infarction

The main goal in the treatment of a patient with acute myocardial infarction is to as quickly as possible resume and maintain blood circulation to the affected area of the heart muscle. To this end, modern medicine offers the following tools:

Aspirin( Acetylsalicylic Acid) - inhibits platelets and prevents the formation of a blood clot.

Already for several decades, acetylsalicylic acid has been used to prevent infarction and thrombosis, however, prolonged use of the drug may lead to gastrointestinal problems, such as heartburn, gastritis, nausea, stomach pain, etc. To avoid such undesirable consequences, it is necessary to take the drugs in a special enteric coating. For example, you can use the drug Trombo ACC, each tablet is covered with a special film shell, resistant to the action of hydrochloric acid in the stomach and dissolving only in the intestine. Thus, the substances that make up the drug do not harm the stomach. For better effect this tool is recommended to take every day, not courses.

Heparin, low molecular weight heparins( Lovenox, Fraxsiparin), Bivalirudin - anticoagulants, acting on blood coagulability and factors leading to the formation and spread of blood clots.

Thrombolytics( Streptokinase, Alteplase, Reteplase and TNK-aza) are potent drugs that can dissolve the uzhus formed thrombus.

All of the above groups of drugs are used in combination and are necessary in the modern treatment of a patient with myocardial infarction.

The best method to restore the patency of the coronary artery and restore blood flow to the affected area of the myocardium is the immediate procedure of angioplasty of the coronary artery with the possible installation of a coronary stent. Studies suggest that in the first hour of a heart attack, as well as if agioplasty can not be performed immediately - the use of thrombolytic drugs should be made and is preferable.

If all of the above measures do not help or are impossible - an urgent operation of aorto-coronary bypass may be the only way to rescue myocardium - restoring blood circulation.

In addition to the main task( restoration of blood circulation along the affected coronary artery), the treatment of a patient with myocardial infarction has the following objectives:

Limiting the size of the infarction is achieved by reducing myocardial oxygen demand, using beta-blockers( Metoprolol, Atenolol, Bisoprolol, Labetalol, etc.);reduction of the load on the myocardium( Enalapril, Ramipril, Lisinopril, etc.).

Control of pain( pain, as a rule, disappears with restoration of blood circulation) - Nitroglycerin, narcotic analgesics.

Fighting arrhythmias: Lidocaine, Amiodarone - for arrhythmias with accelerated rhythm;Atropine or temporary pacemaking - with a slowing of the rhythm.

Maintenance of normal parameters of vital activity: arterial pressure, respiration, pulse, kidney function.

The first 24 hours of the disease are critical. Further prognosis depends on the success of the measures applied and, accordingly, how much the heart muscle "suffered", as well as the presence and extent of the "risk factors" of cardiovascular diseases.

It is important to note that with a favorable course and effective rapid treatment of a patient with myocardial infarction, there is no need for strict bed rest for more than 24 hours. Moreover, an excessively long bed rest can have an additional negative effect on post-infarct recovery.