What causes a person to lose consciousness? Loss of consciousness due to heart disease - simple fainting or loss of life

At least once in their life, every person has experienced fainting or near-fainting. In this case, for many, fainting becomes a cause of worry and anxiety, most often because such a reaction of the body is not always clear.

Fainting is a sudden loss of consciousness a short time(from a few seconds to 5 minutes), which causes a decrease blood pressure. The most common cause of fainting is acute failure blood circulation, due to which blood circulation in the brain decreases and, as a result, to a lack of oxygen supply to the brain.

The insidiousness of fainting is that it always happens suddenly, and if you think that you are young and relatively healthy, so loss of consciousness does not threaten you, then you are very mistaken. Fainting can happen at any age, in both women and men. He may well have healthy people, for example, with a sharp change in body position from horizontal to vertical, with a strong emotional outburst, in a stuffy space and for many other reasons.

The picture of fainting can be described as dizziness, darkening of the eyes and tinnitus, an attack of lightheadedness, pallor, nausea, weakness in the legs, cold sweat. In most cases, all these signs are not dangerous and pass quickly. A hot day, overeating, severe stress- all this is enough for blood pressure to drop. A sharp decrease in pressure, even for a few minutes, disrupts blood flow in the brain, causing loss of consciousness in the patient.

Most often, women become victims of fainting, since their blood pressure is more susceptible to fluctuations and their nervous system is more vulnerable.

Causes of fainting

The causes of fainting are quite varied: from cardiovascular diseases, pregnancy, blood loss, overheating to the point of banal fright or “hungry” fainting in women who abuse their diet. Doctors still have not been able to fully figure out why, under certain circumstances, a person’s blood pressure drops sharply and he loses consciousness. The real reason fainting can be detected only in half of the patients.

Vasodepressor syncope is the most common option fainting in adolescence and youth. This condition can often be provoked by emotional reactions (fear, the sight of blood) or staying in a stuffy room.

Situational syncope can occur under certain circumstances. Fainting associated with defecation occurs, where straining plays an important role, which causes an increase in intrathoracic pressure and a decrease in venous return. A similar mechanism is also triggered when coughing faints, which occurs in patients with chronic obstructive pulmonary diseases.

One of common reasons fainting in older men is hypersensitivity of the carotid sinus if they suffer from arterial hypertension and atherosclerosis of the carotid arteries. This type of fainting can be caused by wearing a tight collar or turning the head suddenly. The mechanism of fainting is associated with activation of the vagus nerve.

The most common cause of fainting (25%) is heart disease. Moreover, this is the most dangerous option fainting, which you should pay attention to first of all. Quite often, fainting occurs in older people due to heart rhythm disturbances. And if other types of fainting occur, as a rule, in an upright position, then such cardiogenic fainting can also happen with bedridden person. The danger of such fainting is that it occurs very suddenly, unlike vasodepressor fainting, when pathological condition preceded palpitations. If a patient falls, he may even be injured.

First aid for loss of consciousness

Usually, fainting states pass very quickly on their own, as soon as the patient takes a horizontal position and the blood is evenly distributed throughout the body.

The first thing you can do for someone who has fainted is to provide sufficient access to fresh air and place them in a horizontal position.

To help the patient come to his senses faster, you can spray it in his face. cold water or hold cotton wool under your nose ammonia. When the person comes to his senses, you can offer him strong tea or coffee, as well as a piece of dark chocolate to raise blood pressure.

(obsolete medical name Syncope is a condition characterized by loss of consciousness and a drop in blood pressure. Metabolism slows down, sudden weakness and confusion. Fainting can last from a few seconds to tens of minutes.

In most cases, fainting is caused by a sudden decrease in metabolism in the brain, cerebral circulation is disrupted, and the brain stops receiving enough oxygen. Even though the brain is not functioning at full capacity, the basic vital functions decrease, but do not disappear completely. The patient is breathing, the heart is working.

Loss of consciousness may be caused by the most various diseases. Sometimes fainting occurs due to a coincidence of circumstances - fatigue, stuffiness, prolonged fasting.

Before fainting, there is always a pre-fainting state, which can also last from a few seconds to several minutes. In some cases, it is enough for the patient to sit or lie down and relax the collar to avoid fainting.

Presyncope is characterized by the following symptoms:

pulsation in temples;
difficulty breathing - a subjective feeling of lack of oxygen;
increased sweating;
feeling of heat throughout the body;
nausea, dizziness;
tachycardia, feeling of rapid heartbeat;
appearance dark spots before your eyes.

If the patient fails to sit down, he faints. In most cases, patients quickly recover without outside help(although this does not mean that it does not need to be provided). Sometimes after fainting there are other unpleasant symptoms, such as trembling and involuntary twitching limbs, urge to urinate.

Causes of fainting

There are several physiological reasons which can lead to short-term loss of consciousness. Let's look at some of them.

Disturbances in autonomic functioning nervous system. This system is responsible for vascular tone. If there is a malfunction, it cannot correctly give commands to the vessels, they contract sharply, and loss of consciousness occurs. This is the main cause of neurogenic fainting - the most common fainting.
Diseases of cardio-vascular system. They are the cause of the so-called. cardiogenic syncope. The heart does not work well enough, the blood vessels narrow, which leads to brain hypoxia.
Atherosclerosis and vascular diseases. This also includes ischemic attacks and strokes.
Promotion intracranial pressure. Occurs as a consequence of certain diseases - tumors, congenital hydrocephalus, or against the background of cerebral hemorrhage, as well as after head injuries.
Decreased blood glucose, decreased oxygen concentration in tissues. Such conditions occur with diabetes, anemia, kidney and liver failure.
As a result of a decrease in the volume of fluid circulating in the body. May be the result of bleeding, diarrhea, or other excess fluid loss.
Toxin poisoning: carbon monoxide, ethyl alcohol and others.
As a result of various psychological and psychiatric diseases. For example, with neuroses, anxiety states common symptom- This is hyperventilation. The body tries to control the oxygen content, which leads to vascular spasm. In such cases, patients need to learn breathing techniques.

There are others causes: infectious diseases, traumatic brain injuries, epileptic seizures. In every special case It is necessary to undergo an examination to find out why fainting occurs.

If this is an isolated case, and there were no pathologies during medical examinations before, there is no need to worry. But if fainting recurs, you need to visit a neurologist.

Our doctors

Types of fainting

The classification of fainting is based on the causes of loss of consciousness. There are three main types of fainting:

neurogenic;
cardiogenic;
hyperventilation.

Among neurogenic syncope, in turn, a distinction is made between vasodepressor and orthostatic. The first ones are the most common, usually occurring in fairly young patients in stuffy conditions, stress, fatigue, or lack of nutrients.

Orthostatic fainting occurs when there is a sudden change in body position (usually during a sudden rise or standing). It may also be caused by taking certain medications.

Cardiogenic loss of consciousness occurs when the heart rhythm is abnormal and can accompany a heart attack. Cardiogenic syncope accounts for up to a quarter of all cases of loss of consciousness, especially among the elderly population.

Hyperventilatory syncope occurs due to rapid breathing. This symptom is characteristic of panic attacks and anxiety attacks. Sometimes this condition is called a vegetative crisis.

Clinical picture

Fainting is characterized by rapid development. Loss of consciousness occurs rapidly. Sometimes patients don’t even have time to realize that something is wrong. In other cases there are typical symptoms pre-fainting state.

Fainting characterized by the following clinical manifestations:

lack of consciousness;
weak pulse;
decreased breathing rate (bradypnea);
lack of pupillary reaction to light;
the patient comes to his senses within 1-5 minutes (if fainting lasts longer, this is serious);
after fainting, pallor and weakness persist;
for some time afterward, low blood pressure is observed;
Dizziness and nausea may occur.

In most cases, syncope occurs when the patient is in an upright position. If the patient loses consciousness while lying down, then it is necessary to suspect a serious somatic pathology.

Diagnostic measures

Diagnostics begin with initial appointment from a neurologist. First, the doctor will try to find out in what circumstances, under the influence of what provoking factors, loss of consciousness develops. To establish final diagnosis You will need to undergo a series of instrumental examinations.

Thus, if cardiogenic fainting is suspected, the patient is referred for an ECG, ECHO-cardiography, and also for consultation with a cardiologist. If epilepsy is suspected, an electroencephalogram is performed. It is also common to take a blood sample to check blood sugar levels to rule out hypoglycemia. If anemia is suspected, it is necessary to conduct a blood test for hemoglobin content. If there is a possibility of neurological or organic diseases brain, then CT and/or MRI, as well as vascular examination, are prescribed.

Treatment It is carried out on an outpatient basis; it is enough to undergo an examination and receive treatment prescriptions.

First aid for fainting

It is important to know how to provide first aid if you lose consciousness.

The patient should be placed on his back with exalted position lower extremities.
Unbutton your collar, loosen your tie, remove your scarf, and provide fresh air.
To speed up the return to consciousness, you can sprinkle the patient with cold water. For the same purposes, it is recommended to use ammonia.

If the patient does not come to within 2-3 minutes, you must call an ambulance. With prolonged fainting, even after returning to consciousness, the patient may experience some dysfunction.

Fainting should be treated qualified specialists. Neurologists at the CELT clinic are ready to carry out all necessary diagnostics and assign the maximum effective treatment. Modern equipment and highly qualified doctors are the key to patient health.

Some people are familiar with the feeling of fainting, which is characterized by loss of consciousness. The types of fainting depend on the causes of its occurrence. The symptoms are similar in many cases. It should be noted that fainting is common during pregnancy, in children, during illness, and especially at times of hunger (hunger fainting). Treatment takes into account the characteristics and causes of the condition.

Fainting occurs due to many factors. Often they lie in a physiological balance that is disrupted at a specific period of time. It should be noted that fainting does not appear until after all the factors for its occurrence have occurred. Fainting appears immediately as a consequence of all favorable conditions for this.

Since readers of the online magazine site may have experienced fainting themselves or observed it in other people, it is necessary to know why it occurs and how to behave if it happens to another person.

What is fainting?

Let's start by defining what fainting is. This momentary loss consciousness, which occurs due to impaired blood circulation in the brain. This condition is temporary. In some cases, it lasts no more than a minute, since blood circulation is quickly restored.

Fainting with loss of consciousness is a protective way for the brain to recover poor blood supply. Oxygen deficiency disrupts metabolic processes. Dizziness and subsequent fainting are often the consequences of some ailment, which specialists can find out about after diagnosing the body. Many illnesses can cause fainting. These include aortic stenosis, anemia, and myocardial infarction.

If a person has a fainting condition or faints, then you should find out why this happened.

Causes of fainting

It is not possible to give the entire list of diseases that cause fainting. A lot of pathologies can develop in the human body, therefore there are also enough factors that provoke loss of consciousness. Often we're talking about about disorders in the cardiovascular or nervous systems:

Demotion cardiac output(angina attacks, heart rhythm disorder, aortic stenosis).
Defects nervous regulation capillaries (rapid change of body position).
Hypoxia.
Decline blood pressure when the body does not adapt to the rapid change in blood flow through the capillaries.
Diseases leading to heart rhythm disturbances. Human body feels oxygen deficiency, which provokes fainting.
Dilatation of muscle blood vessels as a result of physical activity.
A decrease in the amount of circulating blood, which is possible with blood loss or dehydration (diarrhea, excessive urination, sweating).
When swallowing food, coughing or urinating, which indicates a dysfunction of organs in these systems.
Hyperventilation of the lungs with anemia, low blood sugar or carbon dioxide.
Micro-strokes in elderly people due to decreased blood supply to certain segments of the brain.
Dehydration.
Diabetes.
Parkinson's disease.
Vascular disorders in the limbs.
Medicines that affect blood pressure.
Brain hemorrhages.
Migraine-like conditions.
Pre-stroke conditions.
Heart rhythm abnormality: either fast or slow.
Aortic stenosis (dysfunction of the heart valves).
High pressure in arteries or capillaries.
Cardiomyopathy.
Aortic dissection.
Epileptic seizures, which are associated with the functioning of the brain.

Types of fainting

There is no officially accepted classification of types of fainting. However, you can distinguish them independently according to the factors of their occurrence:

Somatogenic. Associated with dysfunction internal organs. Happens:

Cardiogenic – with heart pathologies, when not enough blood is ejected from the left ventricle. It is observed with narrowing of the aorta and arrhythmias.
Hypoglycemic – with a decrease in blood glucose. Observed in diabetes mellitus, fasting, tumor processes, hypothalamic insufficiency, fructose intolerance.
Anemic - with low hemoglobin or red blood cell counts due to blood diseases.
Respiratory – with a decrease in lung capacity, which is observed with various diseases of this organ, for example, with emphysema, whooping cough, bronchial asthma.

Neurogenic. Associated with nervous processes, often with the functioning of receptors. The reflex system activates the parasympathetic nervous system and inhibits the sympathetic one. Blood is retained in the muscles and is not delivered to the brain as a result of the corresponding processes. Here they highlight:

Painful fainting.
Irritative – irritation of receptors of internal organs.
Dyscirculatory – defects in neurological diseases in the regulation of capillary tone.
Maladaptive – adaptive dysfunction of the body (intensive physical stress, overheating).
Orthostatic – insufficient effect on the capillaries of the lower extremities.
Associative - reminiscent of the experience of situations of past fainting states.
Emotional – due to strong emotional experiences. It is characteristic of persons prone to hysteria and suffering from neurosis-like conditions.

Extreme. Associated with extreme situations when the body is forced to mobilize strength. Happens:

Hypovolemic - with blood loss or dehydration.
Hypoxic – with a lack of oxygen, for example, in the mountains.
Hyperbaric – when under high pressure.
Intoxication - in case of poisoning of the body, for example, carbon monoxide, alcohol or dyes.
Iatrogenic, or medicinal, - in case of overdose of certain medications.

Multifactorial – a combination of several factors.

Symptoms of fainting

Presyncope is accompanied by some symptoms that different people appear in different combinations. This is not fainting yet, but it can lead to it. Symptoms of presyncope are:

Lightheadedness.
Goosebumps or veils before the eyes.
Nausea.
Tinnitus.
Yawn.
Sudden weakness.
Legs wobbly, weak and unruly.
Premonition of impending fainting.
Numbness of the tongue and fingertips.
Lump in throat.
Air shortage.
Anxiety.

When fainting occurs, it is characterized by the following symptoms:

Cold sweat.
Light blush.
Dilated pupils that respond slowly to light.
Pale skin.
Decreased muscle tone.
Ash gray skin color.
Weakness of pulse.
Fast or slow heartbeat.
Reduced or completely absent reflex reactions.

The average duration of fainting is from a few seconds to a minute. Duration of more than 4-5 minutes is accompanied by convulsions, increased sweating and possible spontaneous urination.

When you faint, consciousness suddenly turns off. However, it may be preceded by a faint state, which is characterized by the following symptoms:

Noise in ears.
Dizziness.
Acute weakness.
Numbness of the limbs.
"Vacuum" in the head.
Yawn.
Nausea.
Darkening in the eyes.
Sweating.
Paleness of facial skin.

Fainting occurs more often in a standing position, less often in a sitting position. It goes away quickly when lying down.

After recovering from a fainting state, a person may experience the following symptoms within 2 hours: headaches, weakness, increased sweating.

Thus, there are 3 phases of fainting:

Pre-fainting (lipothymia) - lasts 30 seconds - 1 minute before fainting. Sometimes this is where it all ends if the person takes a lying position.
Fainting – can occur without presyncope. You can feel the ground leaving under your feet, gradually sliding down, weakening your muscles. Failure to restore blood supply to the brain within 20 seconds is accompanied by spontaneous bowel movements, urination, or convulsions.
Post-syncope state (post-syncope stage) – gradual return of consciousness. Restores vision, hearing and sensation own body. Orientation in time, space and one’s personality is restored. A person experiences fear, fatigue, weakness, accelerates heartbeat, breathing quickens.

Fainting during pregnancy

Many girls and women dream of getting pregnant and becoming mothers. However, there are frequent cases of fainting during pregnancy. Why is such a happy period overshadowed by fainting states? Not every woman experiences them, but they are quite common.

Fainting is often attributed to low blood pressure, which can be caused by:

Stifling.
Overwork.
Emotional instability.
Various respiratory pathologies.
Hunger.
Exacerbation of chronic diseases.

The enlarging uterus begins to put pressure on the capillaries that are nearby. This leads to a decrease in blood flow into lower limbs, pelvic and back organs. Lying down can make things worse. This leads to a drop in pressure.

Also occurs during pregnancy physiological changes. The amount of blood increases by 35%, which can also lead to fainting until the body adapts.

The amount of blood increases due to an increase in plasma volume. In this case, the blood becomes thin due to the low number of red blood cells. It leads to low level hemoglobin and, accordingly, anemia.

Low glucose levels also affect the condition of a pregnant woman. Improper or inadequate nutrition is a consequence of toxicosis. Because of this, microelements decrease in quantity, which leads to fainting.

Fainting in children

Conditions become quite disturbing when fainting occurs in children. Moms want to know why this happens to their children, as well as what to do in such situations. Let's try to figure it out.

The cause of fainting in a child may be:

Emotional turmoil.
Hunger.
A stuffy room in which the child spent time in a standing position.
Strong pain.
Frequent deep breathing.
Blood loss.
Infectious diseases.
Disturbances in the functioning of the ganglion nervous system.
Low blood pressure.
Quickly change body position from lying to standing.
Brain injuries.
Disturbance of the myocardial conduction system.
Atrioventricular block (Morgagni-Adams-Stokes syndrome), which is accompanied by convulsive attacks, fainting, bluish skin and pallor. It often comes at night and goes away on its own.

What can parents do if their child faints?

Place the baby on the bed.
Remove the pillow from under your head and raise your legs 30°.
Provide Fresh air and its flow to the body: unbutton tight clothes, remove them from your throat, open a window, etc.
Bring to consciousness various stimuli: mother’s perfume, ammonia, spray cold water or rubbing your ears.

When the baby regains consciousness, you need to let him lie down for 10-20 minutes, then give him sweet tea.

Hungry faint

Frequent fainting occurs in women who exhaust themselves with strict diets and hunger strikes. Wanting to become beautiful, many forget about physiological characteristics body, which must receive carbohydrates, proteins and fats in the required quantities every day. Hungry fainting occurs after exhausting diets, when there is a deficiency of some element in the body.

Since the body does not receive enough fat, protein or carbohydrates, it is forced to change metabolic functions to replenish itself. Reserves exist, but not in all systems. First of all, the nervous system suffers, as it does not receive enough of the necessary elements.

Stress can also cause hungry fainting. When the body is under stress, it activates all its energy reserves. Blood pressure rises, blood flow occurs to to the necessary authorities for survival. If the brain does not receive enough of the necessary elements, then fainting occurs.

Factors of hungry fainting also include excessive physical exercise when the body uses up all available elements. Their deficiency primarily affects the functioning of the brain.

Treatment of fainting

When fainting occurs, the most important task is to eliminate the cause that caused it. For example, extreme syncope requires only avoidance of the corresponding stressful situation, and hungry fainting is corrected by observing good nutrition. Treatment in in rare cases requires a medicinal approach.

First of all it is given ambulance to restore hemodynamics. To do this, the body is given a horizontal position, and the legs are raised slightly above the head.

Pharmacological assistance is necessary only in cases where fainting conditions are a consequence of dysfunction of individual body systems, for example, heart pathology or disturbances in the functioning of the nervous system. Prior to this, people who experience fainting conditions are taught various measures how to behave when it occurs:

Clench your palms into fists.
Cross the lower limbs.
Take as horizontal a position as possible.

Bottom line

Fainting is a quickly occurring consequence of some unhealthy condition. There is no need to worry about its occurrence, since we are talking only about disruptions in work circulatory system. If you consult a doctor for medical care, then you can quickly establish the causes of your condition.

Close relatives should know what to do in a situation where others faint. This condition is reversible. However, treatment should not be ignored, especially when it comes to disorders and pathologies in the body.

Syncope is a short-term sudden fainting caused by sharp decline blood flow in the brain.

What could be the reasons for loss of consciousness? Learn the first signs, risks and methods of helping someone who has suffered sudden loss of consciousness.

What is syncopation

Syncope is physical state, characterized sudden and quick loss consciousness(usually accompanied by a fall) followed by an equally rapid spontaneous recovery.

In common parlance, the described condition is called by the more familiar term - fainting.

It must be emphasized that sudden fainting can be said if the following conditions are simultaneously met:

Unconscious state should be short(on average 15 seconds, and only in some cases several minutes) and be accompanied by spontaneous recovery. IN otherwise What occurs is not fainting, but coma.
Loss of consciousness must be accompanied loss of balance. In some forms of seizures that cannot be classified as syncope, there is no loss of postural tone (standing or sitting position is maintained).
Loss of consciousness must be a consequence stopping or reducing blood flow to the brain. Which, however, quickly returns to normal physiological values. For this reason, for example, a decrease in blood glucose levels, which can also lead to loss of consciousness and a fall, is not classified as syncope, since cerebral perfusion (blood supply) remains normal.

Pathogenesis - the process that leads to fainting

To maintain a state of consciousness, the brain needs to receive a lot of blood, which is about 50/60 milliliters per minute for every 100 grams of its tissue.

The supply of this amount of blood is maintained by perfusion, i.e. the pressure with which blood circulates in the brain tissues, which, in turn, is a direct consequence of blood pressure and cerebral vascular resistance.

For this reason, any factor that lowers blood pressure and increases cerebral vascular resistance will reduce cerebral perfusion pressure and therefore the amount of blood flowing to the brain.

On the other hand, blood pressure is closely related to the distance of blood flow and the decrease in resistance peripheral vessels. The range of blood passage, in turn, is ensured by the heart rate, i.e. the amount of blood that is pumped for each blow. The reduction in vascular resistance depends mainly on the mechanisms that determine vasodilation and, therefore, on the action of the sympathetic system.

To summarize, a decrease in cerebral blood perfusion depends on:

Reduced stroke volume.
Decreased heart rate.
Increased vasodilation.
Increased cerebral vascular resistance.

Symptoms that accompany sudden fainting

Not always, but sometimes the development of syncopation is preceded by prodromal symptoms(proactive).

This symptomatology is called presyncope and is characterized by:

dizziness and nausea.
feeling of lightheadedness.
cold sweat and paleness.
lack of strength, which does not allow you to save vertical position.
flashes and disturbances in the field of vision.

The described symptoms are usually accompanied by loss of consciousness and fall. In some cases, however, syncope does not occur and can be restored. normal condition. Then they talk about interrupted fainting.

Recovery from syncope, as already mentioned, occurs quickly and completely. The only symptom that elderly patients sometimes complain about is a feeling of fatigue and amnesia, which concerns events that occurred during fainting, but which, however, does not compromise the ability to remember subsequent events.

From what has been said, it is obvious that syncope is not a disease, it is transitional symptom, which happens quickly and unexpectedly, and passes just as quickly. Syncopation, in most cases, does not imply serious illnesses, but in some situations may represent a signal of serious danger to the patient's life.

Types of syncopation and causes

Causes of fainting...

Depending on the pathology of the mechanism that causes this condition, syncope can be divided into:

Neurotransmitter frill. This is a group of fainting spells, the peculiarity of which is a general temporary hyperactivity of the autonomic nervous system, which, regardless of our will, regulates blood pressure with the help of blood vessels and heart rate.

As a result of this hyperactivity, blood circulation changes, in particular, bradycardia or vasodilation develops, or both conditions at once. The consequence is a decrease in blood pressure or systemic hypotension, which determines cerebral hypoperfusion and, therefore, a decrease in the release of blood that reaches the brain.

Exist Various types neurotransmitter syncope, the most common are:

Vasovagal. Various syndromes, which are a consequence of stimulation of the vagus nerve and lead to temporary loss of consciousness. The triggers that cause this condition are very diverse, for example, prolonged standing, emotions, etc.
Carotid. Develops due to increased sensitivity of the carotid sinus located in the initial section carotid artery. Common activities such as shaving, adjusting a shirt collar, or tying a knot in a tie can activate the sinus reflex, which causes temporary cardiac asystole (absence of systole (beating of the heart)) as well as hypotension. The consequence is cerebral hypoperfusion and syncope.
Situational. Due to the multitude different situations, which combine forced exhalation with the glottis closed. All this leads to increased pressure inside chest, which prevents the return of venous blood to the heart. This results in a decrease in stroke volume and, consequently, in systemic blood pressure. Receptors located in the carotid sinus “detect” a drop in pressure and, to compensate for the imbalance, excite sympathetic system, which causes an increase in heart rate and constriction of blood vessels. Syncope, in this rapid sequence of events, is a consequence of a decrease in pressure caused by a decrease in stroke volume. Situations that most often cause this type of fainting are coughing, sneezing, straining to defecate, urinating, swallowing, physical exercise, lifting weights, after eating, etc.

Orthostatic hypotension . Orthostatic hypotension is said to occur when, within a few minutes of moving to an upright position, from a lying position, systolic pressure in the artery decreases by more than 20 mmHg. This condition is quite common in older people.

It is often based on the following mechanism:

When moving to a vertical position, about a liter of blood, under the influence of gravity, moves from the chest to the legs. This situation determines a significant decrease in venous return to the heart and, as a consequence, a decrease in stroke volume, since the cavities of the heart are not completely filled. This results in a decrease in stroke volume and blood pressure.

IN physiological conditions The body reacts to such situations through a variety of countermeasures. In older people, however, this subtle mechanism is impaired (neurovegetative failure) and therefore there is no recovery normal pressure, which can lead to fainting.

Neurovegetative failure is caused by several conditions, the most common are:

Parkinson's disease. Degenerative disease of the central nervous system - can affect and alter the autonomic nervous system and therefore the sympathetic nervous system.
Diabetic neuropathy . It is a complication of diabetes that can damage the peripheral nervous system.
Amyloid neuropathy. Degeneration of the autonomic and peripheral nervous system occurs as a result of mutation of a protein (transthyretin) that circulates in the blood. The altered protein settles and attaches to the tissues of the autonomic nervous system, leading to neurovegetative failure.
Alcohol abuse and opiate use. Alcohol and opium derivatives interfere with the functioning of the sympathetic nervous system.
Medicines. ACE inhibitors used for arterial hypertension, alpha blockers for hypertension and prostate hypertrophy, tricyclic antidepressants, etc. may cause fainting, especially in older people.
Orthostatic hypotension, and then syncope due to neurovegetative failure may result from hypovolemia. Those. a decrease in circulating blood volume, which determines a deficiency of venous return.

Syncope from cardiac arrhythmia. Cardiac arrhythmias are disturbances in the normal rhythm of the heart. With these abnormalities, the heart may beat faster (tachycardia) or slower (bradycardia). Both abnormalities can cause decreased cerebral perfusion and thus syncope.

Some of the diseases that most often cause heart rhythm disturbances are given below.

Pathological sinus tachycardia . Increased pulsation due to various reasons (elevated temperature, anemia, hyperfunctioning thyroid gland) above 100 beats per minute.
Ventricular tachycardia. An increase in heart pulsation of more than 100 beats per minute, with the formation of electrical signals from muscle contractions outside the heart, that is sinus node. What gives violations in reduction.
Pathological sinus bradycardia . Decrease in heart rate below 60 beats per minute. It can have many causes - hypothyroidism, diseases of the sinus node (the part of the heart that generates impulses), etc.

Syncope from cardiac or cardiopulmonary disorders. They are heterogeneous, but are determined by a decrease in blood output and, as a consequence, a decrease in cerebral perfusion.

The main ones are:

Heart disease. Those. heart valve disorders. Determines incomplete filling of the cavities of the heart and, consequently, a decrease in stroke volume and hence a decrease in perfusion pressure.
Myocardial infarction. Necrosis of cardiac tissue caused by ischemia due to blockage of one of the arteries of the heart.
Hypertrophic cardiomyopathy . Weakening muscle tissue hearts. This condition results in loss of functionality heart heart, and in some cases may manifest as sudden fainting.
Pulmonary hypertension. Increased pressure in pulmonary artery, which connects the right ventricle of the heart to the lungs and carries venous blood. The increase in pressure occurs due to increased vascular resistance in the lungs or in the case of embolism.

Violations cerebral circulation . Caused by cerebral perfusion (reduced blood flow) when blood flow is blocked in the vessel that supplies the brain and limbs.

Diagnosis of the causes of fainting

Since syncopation appears suddenly, lasts very little, on the order of a few seconds, and disappears quickly and spontaneously without a trace, it is reasonable to assume that it would be very difficult to achieve correct diagnosis. That is, find the reason causing the loss of consciousness. All this means that the patient in many situations will have to go through a long diagnostic course. A process that does not always lead to the identification of the exact cause.

One of the diagnostic methods is the exclusion technique. For this:

Study the medical history. The patient's previous medical history and its possible relationship to loss of consciousness.
Patient examination with measuring blood pressure both in the supine and orthostatic (standing) positions.
ECG to detect any abnormalities in the development of the heart.

Upon completion of this first stage, the data obtained is consolidated and more specific studies are prescribed:

Doppler ultrasound of the heart. To view the muscles in action, along with the valves that close the cavities.
Holter blood pressure study. To evaluate changes in blood pressure values over 24 hours.
Holter ECG. To assess heart rate during the day.
ECG under stress. The presence of coronary heart disease is checked, which may reduce the range of blood delivery.

How to save a person who has fainted

Treatment for fainting will of course depend on the cause and, in general, efforts should be made to avoid further recurrences.

If syncopation is based on somatic diseases, it is necessary to direct treatment to him - when the disease is cured, the problem of fainting disappears. Alternatively, chronic pathologies need to be kept under control.

If fainting caused by arrhythmia, you can install a pacemaker, which normalizes the pulsation of the heart.

If syncope occurs due to severe hypovolemia, intravenous fluids may be given.

Typically, moving to a prone position allows you to return to a state of consciousness. It is also recommended that the victim:

lay down on the floor on his stomach;
raised his legs up so that, under the influence of gravity, blood rushed to the brain.
remained lying there until he recovered completely.

If the patient is quickly brought to an upright position, another syncope may occur.

If loss of consciousness persists for several minutes, you should immediately call an ambulance.

Forecast and possible consequences

Except in cases of serious heart disease that may threaten the patient's life, the prognosis is usually positive.

As already mentioned, syncopation is benign disorder, so it can not be considered a real disease. As such, it does not harm the victim. But, unfortunately, this is not always the case. Loss of consciousness includes loss of vertical position, which is accompanied by a sharp, awkward fall, often leading to serious injuries, especially in older people.

Memory failure
Loss of consciousness
Dizziness
Fainting

Fainting (syncope)- This is a short-term loss of consciousness and a fall against the background of a sudden decrease in metabolism in the brain. Most often, such a decrease occurs as a result of a short-term disruption of cerebral blood flow and, consequently, a lack of oxygen to the brain. This leads to dizziness or loss of consciousness. A temporary deterioration in blood supply to the brain can be caused by heart disease or other causes that do not directly affect the heart.

Fainting is always accompanied fainting– a person experiences a feeling of lightheadedness, circles before the eyes, rapid heartbeat, pounding in the temples, sweating, hot flashes, nausea, a feeling of an impending fall. If you don't sit down in time, you may lose consciousness and fall. The loss of consciousness is short-lived (a few seconds), and the person quickly comes to his senses, finding himself in horizontal position. Rarely, short-term twitching of the limbs, loss of urine and other symptoms occur.

Causes leading to decreased cerebral blood flow and fainting:

1. Disruption of the autonomic nervous system, leading to improper regulation of vascular contractility - the cause of neurogenic fainting (account for more than 50% of all fainting spells)

2. Heart pathology is the cause of cardiogenic syncope (accounts for 25% of all syncope)

3. Vascular disorders (significant atherosclerotic deposits in the vessels of the head and neck, transient ischemic attacks, strokes)

4. Sudden increase in intracranial pressure (tumor, hydrocephalus, hemorrhage)

5. Decrease in the content of oxygen, sugar, electrolytes in the blood (hypoxia, anemia, hypoglycemia, renal and liver failure)

6. Decreased circulating blood volume (bleeding, excessive urination, diarrhea)

7. Poisoning (carbon monoxide, alcohol, etc.)

8. Mental disorders (hyperventilation syndrome, hysterical neurosis)

9. There are also other forms of loss of consciousness - as a result of epilepsy, traumatic brain injury, infections, etc.

Let's look at the most common types of fainting: neurogenic, cardiogenic, hyperventilation.

Neurogenic syncope:

1. Vasodepressor - occurs in young people in certain situations - with pain, fear, emotional stress, the sight of blood, stuffiness, long standing; Vasodepressor syncope accounts for the vast majority of cases of syncope of all types

2. Orthostatic – occurs when standing up abruptly, taking certain medications (antihypertensives, antidepressants, levodopa)

3. Fainting when hypersensitivity carotid sinus - occurs in elderly men with atherosclerosis and arterial hypertension when wearing tight collars

4. Fainting with increased intrathoracic pressure - occurs during night urination in elderly men, during coughing, defecation

Cardiogenic syncope occur with cardiac arrhythmias, conduction block, myocardial infarction.

Hyperventilation syncope occur during an attack of anxiety, fear, panic attack(vegetative crisis) as a result of an unconscious increase and deepening of breathing.

For bradycardia(when the heart rate is below 60 beats per minute), short-term attacks of loss of consciousness (seconds) may be observed - “walked, walked - came to consciousness lying on the floor.” It is important to note that the change in contraction frequency should be sharp and fast, up to 20-30 beats per minute. An attack of bradycardia may be preceded by a feeling of “hot flashes in the head.” Such fainting states are caused by a sharp decrease in blood supply to the brain and are characteristic of various types arrhythmias.

Diseases that can cause fainting

Aortic stenosis
Dehydration
Diabetes
Low blood pressure
Migraine
Parkinson's disease
Pulmonary hypertension
Hit

Possible causes of fainting

Disruption of the autonomic nervous system
Heart pathology
Sudden increase in intracranial pressure (tumor, hydrocephalus, hemorrhage)
Poisoning (carbon monoxide, alcohol, etc.)
Mental disorders (hyperventilation syndrome, hysterical neurosis) Epilepsy
Traumatic brain injury

Causes of loss of consciousness

Fainting is most often caused by reasons that do not directly affect the heart:
Postural (orthostatic) hypotension: decreased blood pressure due to a change in body position to an upright position after lying or sitting;
Nerve disease in the legs in older people (especially those with diabetes or Parkinson's disease)
High altitude
Fainting in certain situations ( situational fainting), such as:
Taking blood
Urination
defecation,
Swallowing, or
Coughs that cause an involuntary nervous system reflex (vasovagal response) that slows the heartbeat and dilates blood vessels in the legs, a person feels nausea, sweating, weakness shortly before fainting.

Heart-related causes: Heart conditions that may cause fainting or loss of consciousness:
Abnormal heart rhythm (heart beats too fast or too slow).
Heart valve abnormalities ( aortic stenosis or stenosis pulmonary valve).
High blood pressure in the artery supplying the lungs ( pulmonary hypertension arteries).
Aortic dissection.
Widespread diseases of the heart muscle (cardiomyopathies).

Medicines can cause loss of consciousness by changing blood pressure or by affecting the heart.

Vasovagal syncope in children and adolescents

Vasovagal syncope in children and adolescents usually develops due to stress, fatigue or hunger, so it is recommended to avoid these conditions.

Vasovagal syncope accounts for about 50% of all syncope. They are common in healthy people and often occur repeatedly.

Vasovagal syncope is provoked

Anxiety (in this case they often develop in a stuffy, crowded room),

Fear (for example, at a dentist appointment),

Overwork,

Trauma or

Fainting often develops without obvious reasons.

Classic vasovagal syncope is accompanied by arterial hypotension, bradycardia, nausea, pallor and profuse sweating.

The mechanism of fainting is as follows. In response to a decrease in venous return and a decrease in stroke volume, sympathetic tone reflexively increases. In persons predisposed to such fainting, such an increase sympathetic tone may be excessive, and this leads to sharp increase contractility of the heart. From ventricular mechanoreceptors via group C afferent fibers vagus nerves V medulla intense impulses arrive, and this is accompanied by a decrease in sympathetic and an increase parasympathetic tone. As a result, excessive peripheral vasodilation and relative bradycardia develop, which leads to a drop in blood pressure and fainting. Consciousness is quickly restored in a lying position with legs raised.

A test on an orthostatic table (long stay at an angle of 60-80*) can provoke fainting in such patients. Isoprenaline in low doses increases the sensitivity of this test, but in high doses can lead to false positive results.

Vasovagal syncope sometimes occurs in response to sharp pain, especially coming from internal organs. Occasionally it accompanies a migraine attack.

Fainting when urinating most often occurs in older men during and after urination, usually after sleep. It may be a type of vasovagal syncope. Reducing pressure in bladder causes vasodilation and bradycardia due to increased parasympathetic tone.

Which doctors should you contact if you experience fainting:

Cardiologist
Emergency doctor
Gastroenterologist