Myocardial infarction is a disease in which, due to a violation of patency of the coronary arteries, blood access to the heart muscle sharply decreases or stops, which leads to the death of its part.
Myocardial infarction, causes, symptoms and first aid for myocardial infarction.
The immediate cause of a heart attack, as is clear from the definition, is the cessation of nutrition of the myocardium – the muscle wall of the heart. When the blood does not flow to the muscle for a long time, a more or less large focus of necrosis is formed in it. There may be several reasons leading to impaired blood flow through the arteries of the heart. The most common of them, which is observed in 96–98% of patients with myocardial infarction, is coronary atherosclerosis.
. Violation of fat metabolism, in particular, an increase in blood cholesterol, leads to the fact that it and other “harmful” lipids begin to accumulate in the walls of arteries, as a result of which their lumen is narrowed. So-called atherosclerotic plaques form.
They can grow very slowly, which gives manifestations in the form of periodic pain in the heart – angina pectoris, which is easily removed with the necessary medications. In other cases, the growth of plaques is accelerated, they are damaged, a rapidly growing thrombus forms inside the arteries, blocking their lumen. This deprives the heart muscle of nutrition.
There are many factors that predispose to the development of myocardial infarction. Firstly, it is heredity. If blood relatives suffered from heart diseases, especially at a young age, then the risk of myocardial infarction is higher. Fortunately, bad heredity is not a guarantee that a person will fall ill sooner or later..
Much more important are lifestyle factors. The probability of the disease increases with a sedentary lifestyle, smoking, alcohol abuse, malnutrition – all this contributes to the development of atherosclerosis. The diet should consist of natural products with a moderate content of sodium chloride and a decrease in the amount of animal fat – the main source of cholesterol. It is necessary to ensure that the diet often had fresh fruits and vegetables.
In rare cases, myocardial infarction can be caused by other causes. For example, in a small number of people predisposed to it, coronary vessels are sometimes spasmodic – their lumen narrows, obstructing blood flow. This can cause myocardial infarction. Such cases in general statistics occupy tenths of a percent, usually occur in young men.
Also, the cessation of blood flow through the coronary vessels can occur due to the inflammatory process in the walls of the vessels. This is possible in patients suffering from relatively rare diseases – vasculitis (Takayasu disease, polyarteritis nodosa, etc.). However, the main cause of myocardial infarction remains atherosclerosis of the coronary vessels.
Symptoms of myocardial infarction.
The complexity of the diagnosis is that myocardial infarction can manifest itself in different ways. In order to correctly establish the disease and provide competent emergency care, you need to know what the picture of acute myocardial infarction may look like. The main symptom is chest pain. Heart attack pain must be distinguished from that caused by angina pectoris, since they have a certain similarity between themselves.
Prenatal angina pectoris pain usually occurs in the left half of the chest, often has a pressing, compressive, sometimes burning character. It is moderate in strength, can give to the left hand, shoulder blade, left side of the neck. Appears with physical exertion or stress, is removed by nitroglycerin. The pain that is observed with the classic picture of myocardial infarction is different..
Firstly, it is usually very strong, many times stronger than ordinary pain with angina pectoris. When patients are asked to describe the nature of the pain, it is often defined as “tearing”. As a rule, the area of unpleasant sensations in the chest is larger in area than with angina pectoris, the pain can be spilled, that is, felt throughout the entire front surface of the chest, although this is not necessary – sometimes it is also determined only on the left. The areas of pain distribution are the same – the left arm, shoulder blade, half of the neck and lower jaw, the space between the shoulder blades. Occasionally, it spreads to the right side of the body..
Myocardial infarction can develop not only with some kind of load (physical or emotional), but also without it. Often, the disease begins in the early morning hours, when no external causes affect a person. From taking nitroglycerin, the pain does not disappear, although it may slightly decrease. Often, in order to relieve discomfort, the use of painkillers with narcotic action is required. The lack of effect from nitrates is a very important criterion that distinguishes myocardial infarction from angina pectoris.
Chest pain in myocardial infarction is very often accompanied by cooling of the arms and legs, the appearance of a cold sweat, a sharp blanching of the skin. Sometimes nausea, loss of consciousness, a feeling of lack of air are possible. If the heart attack is large in size and the heart cannot cope with the load, there are signs of acute heart failure: shortness of breath, wheezing in the lungs, the appearance of a pale bluish or “marbled” skin color, cessation of urine output and other symptoms that are very dangerous and require immediate hospitalization of the patient in intensive care unit.
Sometimes the pain in myocardial infarction in an elderly person can be confused with the sensations caused by osteochondrosis. When the nerve roots are infringed, especially if it happened at the chest level, very similar pains arise. In order to correctly distinguish between these conditions, you need to carefully walk your fingers from top to bottom along the spine, making pressure movements. If the pain intensifies in the thoracic region with pressure near the spine, it means that it is caused by osteochondrosis and is relieved by non-narcotic painkillers, for example diclofenac.
If the disease proceeds classically, as described above, then it will not be difficult to recognize it. However, it can occur in several ways, which you also need to know about. They are more rare, but possible. In some cases, myocardial infarction has a picture similar to food poisoning – nausea, vomiting, abdominal pain. In other cases, dyspnea or heart rhythm disturbances come first..
Occasionally, pain does not bother the chest, but in those areas where it should spread (left arm, half of the neck and lower jaw, shoulder blade). There are cases when a person went to the dentist with complaints of pain in the jaw on the left, and later he was diagnosed with myocardial infarction. Sometimes people who first came to see a cardiologist are surprised to learn that myocardial scars, signs of a heart attack, are found on their electrocardiogram. It turns out that this disease can also be transferred in a painless form, “on the feet.” Especially often, the painless form of myocardial infarction is found in patients with diabetes.
First aid for myocardial infarction.
Myocardial infarction is a very dangerous disease that can be fatal for the patient. In all cases when there is a suspicion of him, the person should be hospitalized as soon as possible. For this disease, there are two so-called “death thresholds”: the largest number of patients dies during the first 3 hours, the smaller – in the first three days. If a person is going through this time, then recovery usually occurs. Therefore, a temporary criterion for medical care is important here, as nowhere else..
During hospitalization, it is advisable to resort to the services of an ambulance station, since its teams are equipped with electrocardiography devices, and this can greatly help in the diagnosis. This is not the only advantage – ambulance staff begin treatment even before the patient is taken to the hospital. This can be very important in saving a person’s life..
However, sometimes (when close to the hospital, relatives have a personal car) it is faster to deliver the patient to the hospital’s emergency room without calling an ambulance. In any case, no matter how the person enters the cardiology department, they should be transported there on a gurney or on a stretcher. You can’t allow physical activity – this can further aggravate myocardial oxygen starvation and increase the area of myocardial infarction.
Although hospitalization is the most important thing to do for the patient in this case, do not forget about pre-medical care. Having established the signs of the disease and suspecting myocardial infarction, it is necessary to provide the person with physical rest. Sometimes it is not easy to seat or lay such a patient. Many experienced doctors identified symptoms of myocardial infarction among the symptoms of myocardial infarction. Indeed, severe stress in the conditions of a vascular disaster for the body, pain – all this contributes to the fact that a person can panic and become almost uncontrollable.
Reassuring the patient, you must immediately give him a tablet of acetylsalicylic acid. It dilutes the blood, which helps to slow the growth of a blood clot in a clogged coronary artery and improves blood circulation to the heart. It is very important to remember that the patient is given a pill to chew, and not swallow, washed down with water. A chewed tablet is absorbed much faster in the mouth and stomach.
The next step is pain relief. In any case, even if the symptoms clearly indicate myocardial infarction, in which nitrates are ineffective as painkillers, the patient needs to take a nitroglycerin tablet under the tongue. Even if the pain cannot be relieved, the drug has a relaxing effect on the muscle cells of the vascular wall, which improves blood flow in the arteries that feed the heart.
5 minutes after the first dose of the drug, you can give a second. Nitroglycerin should not be given when the upper (first) digit of the patient’s arterial pressure is lower than 90 mm Hg. Art., for example, it is 85 and 60 mm Hg. Art. Nitrates reduce blood pressure, and if it is already low, the patient’s condition can worsen even more. With severe pain, you can also use any available non-narcotic analgesics, preferably intramuscularly – for a faster effect. Although they are not able to completely remove the pain symptom, even its slight decrease can bring relief to the patient.
It is necessary to control blood pressure and heart rate. With myocardial infarction, blood pressure can be any – normal, low (this is an alarming sign that warns of the development of acute heart failure) or high. The pulse due to the stress response to pain is usually accelerated (80-120 beats per minute). If myocardial infarction occurs against a background of high blood pressure, try to reduce it..
For this, let’s take captopril under the tongue at a dose of 25-50 mg or drugs from the group of adrenergic blockers, which include anaprilin, metoprolol. The latter are especially indicated for heart attack, as they reduce oxygen starvation of the heart muscle. Nifedipine, still widely used in hypertensive crises, is strictly contraindicated in cases of suspected myocardial infarction – it can lead to an expansion of the boundaries of damage.
Based on the book “Quick help in emergency situations”.