Ventricular fibrillation, causes, symptoms, diagnosis and treatment of pathology. A complete description of ventricular fibrillation: symptoms and treatment. Does ventricular fibrillation always end in clinical death?

From this article you will learn: what kind of arrhythmia is called ventricular fibrillation, how dangerous it is. The mechanism of development of arrhythmia, causes and main symptoms of fibrillation, diagnostic methods. Treatment, first aid and professional cardiac resuscitation techniques.

Article publication date: 07/05/2017

Article updated date: 06/02/2019

Ventricular fibrillation is a life-threatening form of heart rhythm disturbance () caused by uncoordinated, asynchronous contraction of individual groups of cardiomyocytes (myocardial cells) of the ventricles.

Conduction of electrical impulses in normal conditions and in ventricular fibrillation

Normally, the rhythmic contraction of the heart muscle is provided by bioelectric impulses that generate special nodes (sinus in the atria, atrioventricular at the border of the atria and ventricles). The impulses sequentially spread throughout the myocardium, excite the cardiomyocytes of the atria and then the ventricles, causing the heart to rhythmically push blood into the vessels.

In pathology for various reasons (cardiomyopathy, myocardial infarction, drug intoxication), the sequence of the bioelectric impulse is disrupted (it is blocked at the level of the atrioventricular node). The ventricular myocardium generates its own impulses, which cause chaotic contraction of individual groups of cardiomyocytes. The result is ineffective heart function, and cardiac output drops to a minimum.

Ventricular fibrillation is a dangerous, life-threatening condition; it ends in death in 80% of cases. The patient can only be saved by emergency cardiac resuscitation measures (defibrillation).

It is impossible to cure fibrillation - arrhythmia occurs suddenly, most often (90%) against the background of serious organic changes in the heart muscle (irreversible transformations of functional tissue into non-functional). It is possible to improve the prognosis and prolong the life of a patient who has survived an attack by implanting a cardioverter-defibrillator. In some cases, the device is installed for prophylaxis when arrhythmia is predicted to develop.

Cardiac resuscitation measures are carried out by the ambulance team or intensive care unit doctors. Subsequently, the patient is treated and monitored by a cardiologist.

The mechanism of pathology development

In the walls of the ventricles there are groups of cells capable of independently generating bioelectric impulses. With complete blockade of the atrioventricular node, this ability leads to the appearance of many isolated impulses circulating through the cardiomyocytes of the ventricles.

Their strength is sufficient to cause weak, isolated contractions of individual groups of cells, but not enough to contract the ventricles as a whole and for a full cardiac ejection of blood.

The frequency of ineffective ventricular fibrillation varies from 300 to 500 per minute, while the impulse does not weaken or interrupt, so the arrhythmia cannot stop on its own (only after or artificial defibrillation).

As a result, the strength of heart contractions, ejection volume, and blood pressure rapidly drop, resulting in complete cardiac arrest.

Causes of the disease

The immediate causes of fibrillation are disturbances in the conductivity and contractility of the ventricular myocardium, which develop against the background of cardiovascular diseases (90%), metabolic disorders (hypokalemia) and certain conditions (electric shock).

Risk factors for developing ventricular fibrillation:

• age (after 45 years);
• gender (in women it develops 3 times less often than in men).

Characteristic symptoms

Ventricular fibrillation is a life-threatening condition with severe symptoms, equivalent to clinical death.

During arrhythmia, the function of the ventricles is impaired, blood does not enter the vascular system, its movement stops, and acute ischemia (oxygen starvation) of the brain and other organs rapidly increases. The patient is unable to move and quickly loses consciousness.

Death in 98% occurs within an hour from the appearance of the first signs of ventricular fibrillation (the time period can be much shorter).

All symptoms of fibrillation appear almost simultaneously:

• heart rhythm disturbance;
• severe headache;
• dizziness;
• heart failure;
• sudden loss of consciousness;
• interrupted breathing or complete absence of it;
• severe pallor of the skin;
• uneven cyanosis (blueness of the nasolabial triangle, tips of the ears, nose);
• absence of pulse in large arteries (carotid and femoral);
• dilated pupils of the eyes that do not respond to bright light;
• convulsions or complete relaxation;
• involuntary urination, defecation (optional).

The period of clinical death (until changes in the body become irreversible) lasts for 4–7 minutes from the moment of complete cardiac arrest, then biological death occurs (when the process of cellular decay begins).

Diagnostics

Ventricular fibrillation is diagnosed based on external symptoms (lack of pulse, breathing, pupillary reaction to light). The electrocardiogram consistently records several stages of arrhythmia development:

1. Short tachysystole or ventricular flutter (15–20 seconds).
2. Convulsive stage (contraction frequency rapidly increases, rhythm is disturbed, cardiac output weakens, takes up to 1 minute).
3. Actually fibrillation of the ventricles of the heart (quite large, but chaotic and frequent (300–400) flickering waves without pronounced intervals and teeth are recorded, changing height, shape, length, the stage lasts from 2 to 5 minutes).
4. Atony (small, short-length and low-amplitude waves appear, lasting up to 10 minutes).
5. Complete absence of heart contractions.

Since any condition with similar symptoms is a direct threat to life, resuscitation measures begin immediately, without waiting for ECG data.

Treatment

It is impossible to cure fibrillation; this form of arrhythmia is a deadly complication that usually occurs unexpectedly. In some cardiovascular diseases, it can be predicted and prevented by installing a pacemaker or cardioverter-defibrillator.

Treatment of fibrillation consists of first aid and cardiac resuscitation, in 20% the victim’s life can be saved.

First aid

If cardiac arrest as a result of ventricular fibrillation did not occur in a hospital, first aid must be provided before the arrival of a professional medical team. There is very little time allotted for it - the heart must be started within 7 minutes, then the victim’s chances rapidly drop.

First stage of emergency care

Call out to the person, give him a boost, hit him hard on the cheek, and perhaps the person will come to his senses.

Place your hand on your chest; its movement indicates the presence of breathing.

Place your ear on your chest in the sternum area (a palm below the subclavian fossa), so you can hear the sound of your heartbeat or feel how your chest rises in time with your breathing.

With your fingers (middle and index) pressed together, try to feel the pulse in any accessible large blood vessel (carotid, femoral artery).

Absence of pulse, breathing, or chest movements is a signal for first aid.

Second stage of emergency care

Lay the victim face up on a flat surface.

Tilt his head back, try to determine with your fingers what is interfering with breathing, clear the airways of foreign objects, vomit, and move the receding tongue to the side.

Ventilate the lungs: hold the victim’s nose with one hand and forcefully blow air “mouth to mouth.” At the same time, evaluate how much the chest rises (artificial respiration prevents the lungs from collapsing and stimulates the movement of the chest).

Kneel to the side of the victim, fold your hands on top of each other (crosswise), begin to rhythmically press on the lower third of the sternum with crossed palms on outstretched arms.

For every 30 rhythmic chest compressions, take 2 deep mouth-to-mouth breaths.

After several cycles of direct massage and ventilation, assess the condition of the victim (perhaps he has a reaction, pulse, breathing).

Direct cardiac massage is performed intensively, but without sudden movements, so as not to break the victim’s ribs. Do not try to start the heart with an elbow strike to the sternum - only very qualified specialists can do this.

First aid is provided before the arrival of the medical team, who must be called before resuscitation begins. The time during which it makes sense to provide first aid is 30 minutes, after which biological death occurs.

Professional Cardiac Resuscitation Techniques

After the arrival of doctors, measures to restore heart function and hemodynamics continue in the ambulance and in the intensive care unit of the hospital.

Apply:

• Electrical defibrillation of the heart (with the help of electrical impulses of different frequencies and strengths, disturbances in the conductivity and excitability of the ventricular myocardium are eliminated and rhythm is restored). If there are no serious organic changes in the myocardium, in the first minutes a defibrillator restores heart function in 95%; against the background of serious pathologies (cardiosclerosis, aneurysm), stimulation is only 30% effective.
• An artificial lung ventilator (the lungs are ventilated manually, using an Ambu bag, or connected to an automatic device, supplying the respiratory mixture through a tube or mask).

The introduction of drugs corrects disturbances in electrolyte metabolism, eliminates the consequences of accumulation of metabolic products (acidosis), maintains heart rhythm, and has a positive effect on the conductivity and excitability of the myocardium.

After an attack of ventricular fibrillation, patients spend some time in intensive care units, during which time the attending cardiologist decides how to improve the prognosis (options being considered are implantation of a cardioverter-defibrillator or a pacemaker).

Complications of the post-resuscitation period

Resuscitation measures (direct massage, defibrillation) manage to save the lives of 20% of patients.

Typical complications of the post-resuscitation period:

• chest injuries and rib fractures (due to intense direct massage);
• hemothorax and pneumothorax (accumulation of blood or air in the pleural cavity of the lungs);
• aspiration pneumonia (due to the contents of the stomach, nasopharynx and oral cavity entering the respiratory tract and lungs);
• disturbances in the functioning of the heart (myocardial dysfunction);
• arrhythmia;
• thromboembolism (blockage of the pulmonary artery with a blood clot);
• disturbances in the functioning of the brain (against the background of hemodynamic disturbances and oxygen starvation).

The result of restoration of heart function and hemodynamics after a long time (10–12 minutes after the onset of clinical death) can be irreversible changes in brain tissue caused by oxygen deficiency, coma, and complete loss of mental and physical disability. Only 5% of cardiac arrest survivors do not have significant brain problems.

Forecast

The appearance of ventricular fibrillation is a poor prognostic sign, the cause of cardiac arrest and death (80%).

In most cases (90%), arrhythmia becomes a complication of serious cardiovascular diseases (congenital defects, cardiosclerosis, cardiomyopathies) with organic changes in the myocardium (small or large foci of scarring). With coronary heart disease, the mortality rate is 34% in women and 46% in men.

It is impossible to cure fibrillation; the patient’s life can be prolonged (20%) only with emergency resuscitation measures. The effectiveness of first aid directly depends on the time of cardiac arrest - in the first minute it is 90%, after 4 minutes it decreases by 3 times (30%).

In some cases, it is possible to predict its occurrence in advance and prevent it by implanting pacemakers or defibrillators (Brugada syndrome). The same methods improve the prognosis after an attack of fibrillation.

Ventricular fibrillation is the most common cause of sudden death after the age of 45 years (about 70–74% annually).

Ventricular fibrillation is a type of cardiac arrhythmia in which the muscle fibers of the ventricular myocardium contract chaotically, ineffectively, with high frequency (up to 300 per minute or more). The condition requires urgent resuscitation, otherwise the patient will die.

Ventricular fibrillation is considered to be the most severe form of cardiac arrhythmia, since in a matter of minutes it causes a stop in blood flow in organs, an increase in metabolic disorders, acidosis and brain damage. Among patients who died with a diagnosis, up to 80% had ventricular fibrillation as its root cause.

At the moment of fibrillation, chaotic, discoordinated, ineffective contractions of its cells occur in the myocardium, which do not allow the organ to pump even a minimal amount of blood, therefore, a paroxysm of fibrillation is followed by an acute disturbance of blood flow, clinically equivalent to that of complete cardiac arrest.

According to statistics, ventricular myocardial fibrillation occurs more often in males, and the average age ranges from 45 to 75 years. The vast majority of patients have some form of cardiac pathology, and non-heart-related causes cause this type of arrhythmia quite rarely.

Fibrillation of the ventricles of the heart actually means its stop; independent restoration of rhythmic contractions of the myocardium is impossible, therefore, without timely and competent resuscitation measures, the outcome is a foregone conclusion. If an arrhythmia strikes a patient outside a medical facility, then the likelihood of survival depends on who is nearby and what actions are taken.

It is clear that a medical worker is not always within reach, and a fatal arrhythmia can occur anywhere - in a public place, park, forest, transport, etc., therefore, only witnesses to the event who can at least try to provide hope for salvation can give primary resuscitation care, the principles of which are taught in school.

It has been proven that correct indirect cardiac massage can ensure blood saturation with oxygen up to 90% within 3-4 minutes even in the absence of breathing, so it should not be neglected even when there is no confidence in the patency of the airways or the ability to establish artificial ventilation. If it is possible to support vital organs until qualified help arrives, then subsequent defibrillation and drug therapy significantly increase the patient's chances of survival.

Causes of ventricular fibrillation

Among the causes of ventricular fibrillation, the main role is played by cardiac pathology, which reflects the condition of the valves, muscles, and the level of blood oxygenation. Extracardiac changes cause arrhythmia much less frequently.

Causes of ventricular fibrillation from the heart include:

• ischemic disease - myocardial infarction, especially large focal ones; the greatest risk of fibrillation exists in the first 12 hours from the moment of necrosis of the heart muscle;
• previous heart attack;
• hypertrophic and dilated cardiomyopathy;
• various forms of disorders in the conduction system of the heart;
• valve defects.

Extracardiac factors that can provoke ventricular fibrillation- these are electric shocks, electrolyte shifts, acid-base imbalances, the effect of certain drugs - cardiac glycosides, barbiturates, anesthetics, antiarrhythmic drugs.

The mechanism for the development of this type of arrhythmia is based on the unevenness of the electrical activity of the myocardium, when its different fibers contract at unequal speeds, simultaneously being in different phases of contraction. The contraction frequency of individual groups of fibers reaches 400-500 per minute.

Naturally, with such uncoordinated and chaotic work, the myocardium is not capable of adequately providing hemodynamics, and blood circulation simply stops. Internal organs and, above all, the cerebral cortex experience an acute oxygen deficiency, and irreversible changes occur 5 or more minutes after the onset of the attack.

Complication ventricular fibrillation itself can be considered, and death, both as a result of the absence or inadequate resuscitation, and if it is ineffective in patients in serious condition.

Upon successful return to life, some patients may experience consequences of intensive care- pneumonia, rib fractures, burns from electric current. A frequent complication is damage to brain tissue with postanoxic encephalopathy. In the heart itself, damage is also possible during the restoration of blood flow after an ischemic period, which manifests itself in other types of arrhythmias and possible heart attack.

Principles of emergency care and treatment of ventricular fibrillation

Treatment of ventricular fibrillation involves providing emergency care as soon as possible, since inadequate heart function can lead to death in a few minutes, and independent rhythm restoration is impossible. Emergency defibrillation is indicated for patients, but if the appropriate equipment is not available, then the specialist delivers a short and intense blow to the anterior surface of the chest in the area of ​​the heart, which can stop fibrillation. If the arrhythmia persists, proceed to chest compressions and artificial respiration.

Non-specialized resuscitation performed in the absence of a defibrillator includes:

• Assessment of general condition and level of consciousness;
• Laying the patient on his back with his head thrown back, moving the lower jaw forward, ensuring free flow of air to the lungs;
• If breathing is not detected - artificial respiration with a frequency of up to 12 breaths every minute;
• Assessment of cardiac work, the beginning of indirect cardiac massage with an intensity of one hundred compressions on the sternum every minute;
• If the resuscitator acts alone, then cardiopulmonary resuscitation consists of alternating 2 air injections with 15 presses on the chest wall; if there are two specialists, then the ratio of insufflations to presses is 1:5.

Specialized cardiopulmonary resuscitation consists of using a defibrillator device and administering medications. It is considered reasonable to take an ECG to confirm that a serious condition or clinical death is caused by this type of arrhythmia, since in other cases the defibrillator may simply be useless.

It is carried out using an electric current with an energy of 200 J. In cases where the symptoms suggest with a high degree of probability that ventricular fibrillation has occurred, cardiologists or resuscitators can immediately begin defibrillation without wasting time on cardiographic studies. This “blind” approach allows you to save time and restore the rhythm in the shortest possible time, which significantly reduces the risk of severe complications during prolonged hypoxia, and is therefore completely justified.

Since fibrillation of the ventricular myocardium is deadly, and the only way to stop it is electrical defibrillation, ambulance teams and medical institutions must be equipped with appropriate devices, and any health worker, accordingly, must be able to use them.

The heart rate may return to normal after the first shock or after a short period of time. If this does not happen, then a second shock follows, but with a higher energy - 300 J. If ineffective, a third, maximum shock of 360 J is applied. After three electric shocks, the rhythm will either be restored, or a straight line (isoline) will be recorded on the cardiogram ). The second case does not yet indicate irreversible death, so attempts to revive the patient continue for another minute, after which the work of the heart is again assessed.

Further resuscitation measures are indicated if defibrillation is ineffective. They consist of tracheal intubation for ventilation of the respiratory system and establishing access to a large vein where adrenaline is injected. Adrenaline prevents the collapse of the carotid arteries, increases blood pressure, and ensures the redirection of blood to vital organs by spasming the abdominal and renal vessels. In severe cases, the administration of adrenaline is repeated every 3-5 minutes, 1 mg.

Drug treatment is administered intravenously and quickly. If access to the vein cannot be obtained, it is allowed to administer adrenaline, atropine, lidocaine into the trachea, and their dose is doubled and diluted in 10 ml of saline. The intracardiac route of drug administration is applicable in extremely rare cases when no other methods are possible.

If two defibrillator discharges are ineffective and the arrhythmia persists, drug therapy in the form of lidocaine is indicated at the rate of 1.5 mg/kg of the patient’s weight, after which a minute later a third attempt at defibrillation is made with an energy of 360 J. If this does not help, then the administration of lidocaine and the maximum discharge is repeated again. In addition to lidocaine, other antiarrhythmics can be administered - ornid, procainamide, amiodarone together with magnesia.

In case of severe electrolyte disturbances with an increase in the level of potassium in the blood serum and acidosis (acidification of the internal environment of the body), in case of barbiturate intoxication or an overdose of tricyclic antidepressants, the administration of sodium bicarbonate is indicated. Its dosage is calculated based on the patient’s weight, half is administered intravenously as a stream, the rest is administered by drip while maintaining the blood pH level within 7.3-7.5. If the treatment attempts were successful, it was possible to restore the rhythm and return the patient to life, then the latter is transferred to the intensive care unit or resuscitation department for further observation. In cases where there is no effect from resuscitation (the pupils do not react to light, there is no breathing or heartbeat, there is no consciousness), therapeutic manipulations are stopped after 30 minutes from the moment they began.

Video: resuscitation for ventricular fibrillation

Further observation of the surviving patient in the intensive care unit is mandatory. The need for it is associated with unstable hemodynamics, the consequences of hypoxic brain damage at the time of ventricular fibrillation or asystole, and gas exchange disorders.

The consequence of suffering arrhythmia, stopped by resuscitation measures, very often becomes the so-called postanoxic encephalopathy. In conditions of insufficient oxygen supply and impaired blood circulation, the brain suffers first of all. Fatal neurological complications occur in approximately one third of patients undergoing intensive care for arrhythmia. A third of survivors have persistent motor and sensory disorders.

Against the background of a developed heart attack after successful restoration of the rhythm, hypotension is possible, requiring appropriate treatment. Drugs from the group (epinephrine, isoprenaline), sodium bicarbonate are prescribed, and if necessary, tracheal intubation with artificial ventilation is performed.

In the first time after restoration of the heart rhythm, the risk of recurrence of fibrillation is high, and the second episode of arrhythmia can be fatal, and therefore it is of utmost importance prevention repeated rhythm disturbances. It includes:

1. Treatment and its;
2. Application for heart rate control;
3. Implantation.

The prognosis for ventricular fibrillation is always serious and depends on how quickly resuscitation efforts begin, how professionally and effectively the specialists work, how much time the patient will have to spend virtually without heart contractions:

• If blood circulation is stopped for more than 4 minutes, then the chances of salvation are minimal due to irreversible changes in the brain.
• The prognosis may be relatively favorable if resuscitation begins in the first three minutes and defibrillation no later than 6 minutes from the onset of the arrhythmia attack. In this case, the survival rate reaches 70%, but the incidence of complications is still high.
• If resuscitation assistance is delayed, and 10-12 or more minutes have passed since the onset of ventricular fibrillation paroxysm, then only a fifth of patients have a chance to remain alive, even if a defibrillator is used. This disappointing indicator is a consequence of rapid damage to the cerebral cortex under hypoxic conditions.

Prevention of ventricular fibrillation is relevant for people suffering from pathology of the myocardium, valves and conduction system of the heart, who need to carefully assess all the risks, prescribe treatment for the causative pathology, and antiarrhythmic drugs. If there is a high probability of ventricular fibrillation, doctors can immediately suggest implantation of a cardioverter-pacemaker, so that in the event of a fatal arrhythmia, the device can help restore heart rhythm and blood circulation.

Ventricular fibrillation is an arrhythmia of the heart muscle, in which the fibers of the ventricular myocardium contract chaotically, uncoordinatedly and quite quickly (up to 300 contractions in one minute).

This heart condition requires urgent, coordinated rehabilitation actions because it can be fatal.

What is ventricular fibrillation?

Ventricular fibrillation is the most complex and severe pathology of cardiac arrhythmia, because in just a few minutes it can cause complications in the bloodstream (cut off the flow of blood to vital organs), acidosis develops, and irreversible processes occur in the brain.

80.0% of deaths due to cardiac arrest occurred from ventricular fibrillation.

At the time of ventricular fibrillation, uncoordinated chaotic contractions occur in the myocardial tissue. These reductions are ineffective because they are unable to pump even a minimal amount of biological fluid.

The blood flow system completely freezes, as happens due to complete cardiac arrest. The blood supply to all centers of the brain, oxygen starvation of the body’s organs and all its systems are disrupted.

Ventricular fibrillation is most common in men aged 45 calendar years to 75 years of age.

This is due to the fact that after 45 years of age there is a restructuring of the body’s hormonal levels and concomitant cardiac pathologies that can cause such arrhythmia of the cardiac organ.

Ventricular fibrillation is essentially cardiac arrest that does not start on its own and requires resuscitation.

Providing emergency care to a patient and performing chest compressions can prolong his life until professional help arrives. Correctly provided first aid gives a person a chance to live.

Causes of ventricular fibrillation

Cardiac pathology is the main reason that causes ventricular fibrillation. This is a pathology that reflects the condition and functioning of the valves, the functionality of the myocardium, as well as blood oxygenation.

Pathologies that are not cardiac in nature very rarely become provocateurs of ventricular fibrillation.

The main provocateur of cardiac pathology is coronary heart disease and its complicated form - myocardial infarction.

A heart attack provokes ventricular fibrillation in the first 12 hours after large-focal necrosis of muscle tissue.

Extracardiac factors that can provoke fibrillation are factors of a traumatic nature, as well as incorrect use of medications that can cause a severe overdose that is dangerous for the body.

Pathogenesis of the pathology and what does fibrillation lead to?

The mechanism of development of this type of arrhythmia occurs from the uneven distribution of electrical current throughout the myocardium. The result is an unequal rate of contraction of the chambers of the heart muscle. Some groups of heart muscles contract at speeds of up to 500 beats per minute.

With such uncoordinated and inadequate functioning of the myocardial muscles, disturbances in hemodynamics occur, and the blood flow simply cannot work chaotically and the system stops.

As a result, oxygen starvation occurs in vital organs and systems that coordinate all human vital functions.

Oxygen deficiency in the brain for more than 5 minutes leads to irreversible processes in the destruction of cells of the cerebral cortex, which leads to their death.

One type of fibrillation can be ventricular flutter. This is a variant of ventricular tachycardia, which forms against the background of fibrillation, and is dangerous for the human body.

Flutter of the heart ventricles during fibrillation

This type of tachycardia, which is caused by rapid contraction of the ventricles, during fibrillation, leads to ventricular flutter.

This type of fibrillation is distinguished by the correct rhythm during contraction, and the frequency of heart impulses reaches up to 300 beats per minute.

Fluttering is a strict adherence to rhythm, fibrillation is chaotic and uncoordinated functioning of the heart chambers.

Stages of ventricular fibrillation and flutter

Ventricular flutter and fibrillation are the most life-threatening pathologies for humans.

• Tachysystolic stage- fluttering lasts only a few seconds. This stage occurs with constant frequency;
• Stage of flutter of a convulsive nature— stage duration is up to 60 seconds. With this flutter, there is a loss of rhythm with an increase in the frequency of contractions of myocardial tissue;
• Fibrillation of the atrial fibrillation stage— duration of arrhythmia up to 180 seconds. When diagnosed on an ECG (electrocardiography), heart contractions are recorded that are irregular in their actions and have different calibers of impulses;
• Stage of atonic fibrillation- this is the stage of arrhythmia, which appears in the fifth minute of an attack of ventricular fibrillation, and manifests itself in low-amplitude and small contractions due to myocardial depletion.

Fibrillation is classified into:

• The form of fibrillation is paroxysmal. This is a form that is characterized by attacks of unorganized activity of electrical cardiac impulses that occur in short periods;
• Permanent form of heart rhythm disorder. Such cardiac arrhythmia can lead to sudden death.

Symptoms

Ventricular fibrillation is a condition of the heart organ that poses a threat to human life. Fibrillation has pronounced symptoms, which are equivalent to clinical death.

During the period of ventricular arrhythmia, disturbances occur in the blood flow, biological fluid does not enter the system, which provokes a second-by-second increase in hypoxia of the brain, as well as all internal organs and systems.

Ischemia develops with every fraction of a second, leading to a person’s inability to move and, due to a lack of oxygen in the brain, to loss of consciousness.

Death occurs in 98%, and it occurs within a few minutes (up to 60 minutes) from the moment the first symptoms appear.

Symptoms of ventricular fibrillation:

Signs of clinical death with fibrillation

The time of clinical death lasts from 4 minutes to 7 minutes. This is the time before irreversible consequences and destruction begin in the body.

If no help is provided during this period of time and the heart does not start working again, the body’s cells begin to disintegrate, which leads to the biological death of a person.

Ventricular fibrillation occurs suddenly and without preliminary symptoms. All the symptoms of fibrillation occur simultaneously and the patient no longer has the opportunity to change anything.

There is no way to predict the development of an attack of fibrillation; everything happens suddenly and quite quickly.

Due to the cessation of the flow of biological fluid into the bloodstream, a person experiences severe symptoms within 15 minutes in the form of dizziness, weakness and headache, and loses consciousness.

After he has lost consciousness, the most difficult period of paroxysm of ventricular fibrillation occurs.

By the first minute after the onset of clinical death, tonic convulsions occur, the pupils of the eyes begin to dilate.

The second minute of the coma stage is characterized by intermittent breathing, or its complete stop, the heartbeat does not appear, and the pulse in the large arteries is not audible. There is no way to measure blood pressure index.

Cyanosis of the nasolabial region appears, and cyanosis appears at the tips of the ears. The neck veins become engorged with blood and become very noticeable. The face takes on a puffy appearance.

By the end of the fifth minute of an attack of clinical death, irreversible processes of decay of the body begin. If resuscitation efforts do not occur, then the person experiences biological death.

It is possible to determine that the cause of clinical death is ventricular fibrillation using a portable cardiograph in an ambulance, and immediately begin to resuscitate the patient.

Diagnostics

Diagnosis of ventricular fibrillation is carried out based on the symptoms of this pathology and quite often already at the stage of clinical death.

The ECG shows several stages of pathology development:

• Short interval tachysystole, as well as ventricular flutter for no more than 20 seconds;
• Seizure stage- HR (heart rate) increases and heart rhythm is disrupted, the release of blood into the bloodstream system weakens. This state takes no more than 60 seconds. More details about heart rate at;
• Ventricular fibrillation is detected- up to 400 beats per minute, and their flickering without pronounced teeth and the necessary intervals. The movements of the heart muscle are frequent, but not uniform and chaotic. The cardiogram shows different heights, as well as the shape and length of the cardiac fibrillation wave. A condition that lasts no more than 120 seconds;
• Atony- low amplitude waves appear. And this state can last up to 10 minutes;
• Complete absence of myocardial contractions.

Interpretation of ECG results

Large-wave ventricular fibrillation depends on the size of the wave, as well as on the randomness of contractions. The force of contraction is higher than 0.50 centimeters recorded on the electrocardiograph. This indication indicates the initial stage of arrhythmia.

As cardiomyocytes weaken, acidosis occurs, and the metabolic disturbances of large-wave arrhythmia enter the state of the small-wave stage of ventricular fibrillation.

This stage means a deterioration in the patient’s condition and probable asystole followed by death.

By reading the ECG, the doctor sees the full picture of the cardiac disorder and makes decisions on resuscitation measures:

• Defibrillation of the heart muscle;
• Administration of antiarrhythmic drugs.

With proper and timely assistance, asystole can be avoided.

Pre-hospital emergency care

In order to save a person’s life, it is necessary to respond promptly to the signs of a heart attack, which may be triggered by ventricular fibrillation:

• The first action is to call an ambulance;
• Lay the patient flat on his back and tilt his head back;
• Ensure the supply of fresh air, unfasten all constrictive elements of clothing;
• If there is no breathing, perform artificial ventilation of the lungs mechanically (mouth-to-mouth breathing);
• The frequency of artificial air injection is at least 12 times and one minute;
• If there is no pulsation of the heart muscle, perform indirect cardiac massage;
• For indirect cardiac massage, it is advisable to have an assistant;
• If a person resuscitates a patient alone, then it is necessary to take into account the rules of chest compressions - inhale air 2 times, then press the chest 15 times, and so on until the emergency doctors arrive.

Qualified resuscitation care

Emergency care for ventricular fibrillation begins with the following measures:

• Determining the cause of an attack using ECG;
• If the cause of clinical death is fibrillation, then the defibrillation method is used (otherwise, defibrillation is useless);
• Administration of antiarrhythmic drugs by injection into the artery.

Defibrillation is a technique for resuscitating the heart using an electric current with a power of 200.0 J.

If the ECG reveals ventricular fibrillation as the cause of cardiac arrest, then this technique is applied immediately, without wasting time on other resuscitation methods.

The use of a defibrillator allows you to quickly start the heart and adjust its rhythm, which helps reduce the risk of complications on the body during a long period of hypoxia.

Defibrillation is the only way to restore the function of the heart organ at the stage of clinical death.

The rhythm of the heart can be restored by the first discharge of a defibrillator. If the rhythm is not restored the first time, after a short period of time, another discharge is given, which has a greater electrical charge - up to 300.0 J.

The maximum acceptable discharge force for the heart muscle is 360.0 J. After three defibrillator discharges, there are 2 options for solving the work of the heart: its rhythm is restored, or an isoline is recorded on the ECG.

After the isoline, resuscitators can try to restart the cardiac organ for another 60 seconds and restore blood flow in the system.

If it was not possible to resuscitate using the defibrillation technique, then the method of injecting Adrenaline into a large artery is used.

Adrenaline raises the level of blood pressure in the blood, prevents the collapse of the carotid artery and redirects the flow of biological fluid to the organs that ensure the vital functions of the human body.

Spasm of the abdominal vessels and renal arteries occurs. In a severe case of the development of a complicated stage of ventricular fibrillation, the drug Adrenaline is injected into a vein, after a time interval of 3 minutes, at a dosage of 1 milligram.

An extreme case of cardiac resuscitation is the injection of adrenergic agonists directly into the heart muscle.

In case of electrolyte imbalance, regulators are introduced according to individual dosage, based on the patient’s body weight. 50% of the dose of the drug is injected as a stream into the artery, the remaining 50% - by drop method (until the blood pH reaches at least 7.3-7.5). Chances of surviving defibrillation

Preventive measures for repeated attacks of asystole

In the first period after the resumption of the cardiac organ, relapses of fibrillation are possible, which can provoke asystole. This relapse can be fatal for a person.

To prevent relapse, it is necessary to carry out prevention, which consists of:

• Treatment of cardiac ischemia and heart failure;
• Use antiarrhythmic therapy to correct heart rhythm;
• Perform surgery on a pacemaker or cardioverter.

Complications after resuscitation

Resuscitation measures can save the lives of 20.0% of patients.

The use of indirect cardiac massage and the impact of a defibrillator on the myocardium cause complications characteristic of the post-resuscitation stage:

• Mechanical injuries of the chest - fractured ribs (consequences of vigorous chest compressions);
• Chest burns (consequences of a defibrillator);
• Pathology pneumothorax (accumulation of biological fluid, or air mass in the pleura of the lungs);
• Pneumonia of aspiration nature (due to the entry of contents of the oral cavity or nasopharynx into the respiratory system);
• Cardiac muscle dysfunction;
• Arrhythmia of the ventricles and atria;
• Pathology thromboembolism (clogging of a pulmonary vessel with blood clots);
• Encephalopathy of the cerebral cortex;
• Disturbances in the brain (due to hypoxia of brain cells).

Antiarrhythmic encephalopathy develops due to hypoxia of brain cells.

Almost 30% of patients who survived a state of clinical death caused by arrhythmia of the cardiac impulse experienced the death of some brain cells, which led to loss of organ sensitivity and disruption of the functionality of the motor system.

Also, as a consequence of restoring rhythm through resuscitation actions, hypotension may develop, which requires proper therapy.

If necessary, ventilation of the lungs is carried out.

Preventative measures for fibrillation

Preventive measures for ventricular fibrillation must be taken for persons suffering from myocardial pathologies that can disrupt the rhythm of heart contractions.

To treat arrhythmia, it is necessary to take antiarrhythmic medications that will correct the functioning of the heart valves and normalize the heart rhythm.

Life forecast

Ventricular fibrillation is a pathology in which the cardiac organ stops in 80.0% of all cases.

This pathology is almost 100% a complicated form of heart disease that was not diagnosed in a timely manner and qualified therapy was not carried out.

Arrhythmia can also manifest itself against the background of congenital pathologies:

• Heart disease;
• Cardiopathy;
• Cardiomegaly;
• Tachyarrhythmia.

Ventricular tachycardia develops due to atherosclerosis and cardiosclerosis. If treatment is not timely, arrhythmia appears, which can provoke fibrillation.

With ischemia of the cardiac organ, deaths occur in 34.0% of women and 46.0% of the stronger sex.

The pathology of ventricular fibrillation cannot be cured.

At the time of an attack, with the coordinated work of resuscitators, only 20.0% of all patients are brought back to life. The main assistant in resuscitation measures is time. In the first minute after cardiac arrest, the organ can be started in 90.0% of patients, and in 4 minutes - only in 30.0%.

Ventricular fibrillation is the most common cause of death after sudden cardiac arrest in heart patients over 45 years of age.

VENTRICULAR FIBRILLATION honey.
Ventricular fibrillation (VF) is a form of cardiac arrhythmia characterized by complete asynchrony of contraction of individual fibers of the ventricular myocardium, causing loss of effective systole and cardiac output. VF means circulatory arrest and is equivalent to death if cardiac resuscitation is not performed.
More than 90% of cardiac arrests are caused by VF,
therefore, chest compressions, electrical defibrillation, mechanical ventilation and drug therapy are started immediately before ECG confirmation.

Classification

Etiology

Clinical picture

ICD

Directory of diseases. 2012 .

See what “VENTRICULAR FIBRILLATION” is in other dictionaries:

Ventricular fibrillation- Fibrillation is the destruction of bonds between individual fibrils of the walls of plant fibers, which occurs when water penetrates into the interfibrillar space, as well as under the influence of mechanical influences on the cell walls of plant fibers.... ... Wikipedia

ventricular fibrillation- (fibrillatio ventriculorum; synonym ventricular fibrillation) cardiac arrhythmia, characterized by complete asynchrony of contraction of ventricular myofibrils, which leads to cessation of the pumping function of the heart ... Large medical dictionary

ventricular fibrillation- rus fibrillation (g) of the ventricles of the heart eng ventricular fibrillation fra fibrillation (f) ventriculaire deu Herzkammerflimmern (n), Kammerflimmern (n) spa fibrilación (f) ventricular ... Occupational safety and health. Translation into English, French, German, Spanish

Atrial fibrillation- ECG of atrial fibrillation (upper) and normal sinus rhythm (lower). The purple arrow points to the P wave, which is missing... Wikipedia

Heart fibrillation- See also: Atrial fibrillation Cardiac fibrillation is a heart condition in which individual groups of muscle fibers of the heart muscle contract separately and uncoordinated, as a result of which the heart loses the ability to perform ... ... Wikipedia

Fibrillation- rapid chaotic contraction of many individual muscle fibers of the heart, as a result of which the heart loses the ability to perform effective and synchronous contractions. The affected area of ​​the heart then stops pumping blood. Fibrillation can... ... Medical terms- (fibrillatio ventriculorum) see Ventricular fibrillation ... Large medical dictionary

Poisoning- I Poisoning (acute) Poisoning is a disease that develops as a result of exogenous exposure to the human or animal body of chemical compounds in quantities that cause disturbances in physiological functions and create a danger to life. IN … Medical encyclopedia

Ventricular fibrillation is an extreme degree of instability of the heart rhythm. It’s hard to imagine, but the pulse can reach 400–600 beats per minute. However, such an increase simply affects the wear and tear of the heart muscle. But what is extremely dangerous is that asynchrony occurs in the contraction of individual adjacent sections of myocardial fibers (heart muscle).

The resulting desynchronization leads to loss of systole efficiency, leading to impaired cardiac output, up to circulatory arrest. Perhaps short-term, but this may well be enough to cause death if urgent resuscitation assistance does not arrive.

It is worth understanding that, based on the frequency of exposure, small-wave ventricular fibrillation and large-wave ventricular fibrillation are distinguished, but in both cases such exposure leads to asynchronous contractions of the myocardium.

The most effective way to eliminate ventricular fibrillation is short-term exposure to an electrical impulse. True, this requires high voltage (up to 7000 volts when exposed through an unopened chest).

Ventricular fibrillation is a heart rhythm disorder that is characterized by chaotic and ineffective contraction of the heart muscle at a high frequency (about 300 beats per minute or higher). This pathology seriously threatens a person’s life and requires immediate medical attention.

Attention. This condition is considered the most dangerous type, since ventricular fibrillation almost instantly stops the flow of blood in the organs, increases metabolic disruptions, causes acidosis and damage to brain tissue. Most deaths due to asystole occur due to existing ventricular fibrillation.

In this condition, the muscle fibers of the ventricles contract very quickly, randomly and ineffectively, as a result of which the heart is not able to pump even small ones, which provokes circulatory failures in the body of the same severity as when cardiac activity stops.

Most often, ventricular fibrillation affects the stronger sex of middle and old age. As a rule, pathology occurs mainly in patients with any disease of the cardiovascular system.

Important. Ventricular fibrillation is an extremely life-threatening condition that requires immediate intervention from medical professionals. Even timely resuscitation measures from passers-by, performed using the correct technique, can save the patient.

Causes of ventricular fibrillation

Diseases not associated with disruption of the heart and blood vessels rarely provoke the occurrence of this type of arrhythmia. Most often, fibrillation develops with cardiac diseases associated with the functioning of valves, myocardium, or impaired oxygen supply to the heart.

Ventricular fibrillation occurs in the presence of the following pathologies:

• – in case of myocardial infarction, if a large area of ​​the myocardium is affected. In this case, fibrillation most often occurs in the first 12 hours after the development of a heart attack.
• Often this condition develops long after myocardial necrosis has occurred.
• Hypertrophic and dilatational.
• All kinds of disruptions in the cardiac conduction system.
• Congenital heart valve defects.

What else can trigger the formation of ventricular fibrillation:

• Electric shock;
• Disturbances in the electrolyte system;
• Shifts in acid-base balance;
• Taking certain medications - barbiturates, painkillers,...

Ventricular fibrillation develops due to a malfunction in the electrical activity of muscle fibers - they begin to contract unevenly, being in different contractile phases, as a result of which the heart rate reaches enormous numbers - up to 400-500 beats per minute.

Attention. An attack of such chaotic myocardial activity provokes a complete disruption of hemodynamics, as a result of which the oxygen supply of all organs is disrupted, first of all, the cerebral cortex is greatly affected. If the patient is not provided with proper medical care within five minutes, the outcome of the disease is unfavorable and death occurs due to cardiac arrest.

Ventricular fibrillation in children

Atrial fibrillation is very rare among children and is usually a complication of other types of disorders.
heart rhythm (for example, ventricular tachycardia).

In young patients, ventricular fibrillation develops due to the following provoking factors:

• failure of electrolyte balance;
• taking arrhythmogenic drugs;
• disturbance of the sympathetic-parasympathetic balance (especially with increasing concentrations of catecholamines);
• hypo- or hyperthermia;
• primary electrical disease (for example, long interval between Q and T waves);
• hypoxia;
• ischemia.

For reference. With this pathology, continuous waves of various shapes and sizes are recorded on the electrocardiogram with an amount of 200-300 per minute (high-wave ventricular fibrillation) or 400-500 per minute (small-wave ventricular fibrillation).

Symptoms of VF in young patients can be different and depend on:

• type of tachycardia,
• duration of illness,
• age,
• the presence of any heart defects.

Paroxysmal ventricular tachycardia is characterized by a feeling of heartbeat, discomfort in the chest, weakness, dizziness, anxiety, and in some cases the patient may lose consciousness. When the attack lasts for a long time, symptoms of circulatory failure are observed.

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Infants with this pathology may develop:

• rapid shallow breathing,
• dyspnea,
• paleness and cyanosis of the skin,
• lethargic state
• hepatomegaly,
• swelling.

Non-paroxysmal ventricular tachycardia of recurrent type does not manifest itself in most young patients and is usually discovered by chance during a routine medical examination.

Urgent elimination of ventricular tachycardia requires an initial differential diagnosis of supraventricular increased heart rate with an enlarged ventricular complex. If the type of heart rhythm disturbance cannot be determined, therapy is carried out by supplying humidified oxygen and intravenous injection of ATP.

Attention. Urgent medical care is needed for small patients with severe disruptions in blood flow and serious condition, which is accompanied by disturbances of consciousness and fainting.

Classification of ventricular fibrillation

Regarding previous infarctions of the muscular lining of the heart, ventricular fibrillation is divided into primary, secondary and late.

Primary VF develops on the first or second day after myocardial necrosis. It demonstrates that the muscle membrane is characterized by electrical instability, which occurs due to acute oxygen starvation of the muscle.

Attention. Approximately 60% of primary ventricular fibrillation develops within four hours, and most - within twelve hours after the death of the heart muscle. This pathology is characterized by a high percentage of deaths.

If there is failure of the left ventricle of the heart and cardiogenic collapse, in some cases in patients who have had a heart attack, secondary ventricular fibrillation is formed.

In cases where VF develops two days after necrosis of the heart muscle, it is called “late.” Approximately half of patients with this diagnosis die. Typically, this type of disease begins two to six weeks after myocardial infarction. Most often, this VF affects patients with a damaged anterior wall of the organ.

For reference. Doctors classify ventricular fibrillation into two types. If the heart rhythm is regular, the beat rate is 200-300 per minute, they speak of ventricular flutter. With an abnormal heart rhythm and a frequency of about 500 beats per minute, we are talking about flickering of the heart chambers.

What is the danger of fibrillation?

When chaotic work of the muscle fibers of the ventricles occurs, full cardiac output becomes impossible. In addition, the force of contractions of the organ and the pressure in the vessels quickly decrease, which immediately leads to asystole - cardiac arrest.

The body's blood circulation is disrupted very quickly, the circulation of oxygen to tissues and organs is disrupted, and acute oxygen starvation of all systems occurs. The cerebral cortex reacts extremely sharply to hypoxia, and irreversible changes in the brain occur.

Attention! 80% of cases of death are a disappointing figure for the prognosis of ventricular fibrillation.

This condition seriously threatens life, so it is urgently necessary to stop it with the help of resuscitation, to know the correct technique for performing chest compressions, because timely assistance can bring the patient back to life and increase the prognosis for a full recovery.

Ventricular fibrillation - symptoms

VF occurs in exactly the same way as asystole, which is why the following clinical manifestations are observed:

• Almost immediately the patient loses consciousness;
• Breathing and pulsation are not detected, a sharp decrease in blood pressure is observed;
• Skin cyanosis is detected;
• The pupils dilate and do not respond to light;
• Due to oxygen starvation, relaxation of the sphincters of the bladder and rectum is possible - involuntary urination or defecation.

For reference. By the end of the first minute of ventricular fibrillation, the patient remains unconscious, convulsive muscle contractions and dilated pupils are observed. In the second minute, breathing disappears, the pulse cannot be felt, the skin turns blue, the veins in the neck dilate and enlarge, and a puffy face is observed.

Ventricular fibrillation provokes the development of clinical death. When these symptoms appear, there are only five minutes to save the patient and return him to life.

Diagnostic methods

Ventricular fibrillation can be diagnosed only during instrumental examination methods. The key method is electrocardiographic examination of the heart. The advantages of recording an electrocardiogram are the speed of the examination and the ability to carry it out anywhere.

Signs of development of ventricular fibrillation on the ECG:

• Absence of QRS complexes and any intervals and waves;
• Registration of fibrillation waves with a frequency of 300-400 per minute, chaotic, variable in length and amplitude;
• Absence of isoelectric line.

An electrocardiogram can record large-wave VF - if the contraction force is more than half a centimeter based on the length of one cell. This type is typical in the first minutes of the disease.

For reference. Gradually, the heart cells are depleted, the acid-base balance shifts to the acidic side, metabolic changes increase - small-wave fibrillation is recorded. This condition poses the greatest danger to the patient and is characterized by the most unfavorable prognosis.

Urgent Care

VF therapy involves urgent medical care, since this type of arrhythmia is fatal in a matter of minutes, and the heart rhythm does not recover on its own.

For reference. The patient requires immediate defibrillation, but if the necessary equipment is not available, the physician applies a small and quick blow to the anterior chest wall in the cardiac zone, which stops fibrillation.

If the heart rhythm disturbance is not eliminated in this way, the specialist performs chest compressions and artificial respiration.