Fibrillation of the ventricles
Author Ольга Кияница
- 1 Description of ventricular fibrillation
- 2 Symptoms of ventricular fibrillation
- 3 Causes of ventricular fibrillation
- 4 Types / photos of ventricular fibrillation
- 5 Complications of ventricular fibrillation
- 6 Diagnosis of ventricular fibrillation
- 7 Treatment of ventricular fibrillation
- 8 Secondary prophylaxis of ventricular fibrillation
Cardiac fibrillation is a violation of the rhythm of the organ, which results in the impossibility of a normal discharge of blood from the chambers of the heart into the main vessels. There is a disorder of hemodynamics, disturbance of the intake of nutrients and oxygen in organs and tissues. Therefore, the fibrillation of the heart denotes such a rhythm of its activity, when it becomes super-partially, discordi- nated and chaotic.
During fibrillation of the ventricles, they are often reduced to 480 times per minute, which can very quickly go into arrhythmia and complete cessation of human activity.
Fibrillation can occur in different parts of the heart, therefore, depending on the localization of the source of pathological excitation, the atrial fibrillation and ventricular fibrillation are emitted. The latter form most often leads to a severe clinical picture with a fatal outcome. Therefore, for every patient suffering from coronary heart disease or myocardial infarction, it is necessary to know what is dangerous for fibrillation of ventricles and what preventive measures are offered by modern medicine.
Video: Ventricular Fibrillation Animation Video
Description of ventricular fibrillation
Fibrillation, or flickering, of the ventricles (FJ) is a form of arrhythmias in the heart, at which an increase in heart rate occurs from 300 to 480 times per minute. Abbreviations of the ventricles become irregular, chaotic and unproductive, resulting in an increased risk of heart failure.
Trembling of ventricles is a very close condition to fibrillation. When treating the heart rate is 200-300 times per minute.In this condition, the contraction is also ineffective and irregular, the only, disturbed rhythm can go into fibrillation or, which rarely happens, is restored to normal sinus activity of the heart.
Sudden cardiac death develops in 1-6 hours after the beginning of ventricular fibrillation, so, on the background of FH, 75-80% of deaths occur.
There are four stages of development of FJ defined by the American cardiologist Carl J. Wiggersen:
- The first stage is the tremor of the ventricles, which lasts for several seconds and is characterized by an increase in heart rate, but with the preservation of sinus rhythm.
- The second stage - convulsive, at which the heart rate increases to 600 times in
- minute The rhythm becomes uncoordinated, ineffective as a result of excitation of individual regions of the heart muscle. It lasts up to one minute.
- The third stage is flickering of the ventricles, when contractions become even more frequent, but their strength decreases significantly. Duration is up to 3 minutes.
- The fourth is the atonic stage, the excitatory impulses are dying in various parts of the myocardium, the heart rate is reduced to 400 times per minute, the duration of the excitation wave grows, while their amplitude decreases.
Thus, from the appearance of the first signs until the onset of clinical death, minutes pass through, for which it is necessary to have time to render medical assistance to a person.
Symptoms of ventricular fibrillation
The phlogosis develops suddenly and is characterized by a phased appearance of the following symptoms:
- After the beginning of ventricular fibrillation after 3-5 s there is a dizziness and weakness.
- The patient loses consciousness after 15-20 seconds from the onset of the attack.
Cramps appear after 40 s, usually tonic in nature, with which skeletal muscle contraction is observed. Together with this, sphincter relaxes, which leads to involuntary urination and defecation.
- The pupils are expanding 45 after, which in 1,5 minutes become the most expanded. At this stage, there is talk of clinical death, and it is believed that half of the time spent on restoring the working capacity of the brain has expired.
During the onset of PF in the patient, there is a noisy breath, a rumble of hoarseness and frequent respiration. With the advent of clinical death, respiration becomes rarer and gradually ceases to be determined. There is also no pulse in the carotid arteries. The color of the skin becomes pale gray, the pupils are completely enlarged. As a rule, clinical death occurs at the second minute from the onset of an attack.
Emergency care should be provided within the first four minutes, since it is almost impossible to restore normal neuro-regulation in the brain and other organs later.
Causes of ventricular fibrillation
Ischemic heart disease is on the first place among the reasons for the appearance of FG. With disturbances of coronary circulation and organic changes, areas of ischemia are formed, and then necrosis, myocardium. More fibrillation due to coronary heart disease affects men - about 46%, somewhat less ill with the pathology of a woman - in 34% of cases.
Cardiomyopathy , which are of several types. Hypertrophic cardiomyopathy is more common among young people who are actively involved in sports. In the process of adulthood, the risk of FJ due to hypertrophic cardiomyopathy is somewhat reduced. Also, an idiopathic dilated cardiomyopathy is isolated, which provokes the development of FG due to significant hemodynamic disorders. In some cases, fibrillation occurs on the background of arrhythmogenic cardiomyopathy of the right ventricle, but for this disorder a rare occurrence is characteristic.
Heart defects cause PF in case of stenosis of the aortic mouth. With this pathology, as with hypertrophic cardiomyopathy, the left ventricle increases in size and begins to fill up poorly and dispose of blood. The deficiency of the mitral valve can also cause FH, but much less often than with stenosis. Mostly, the rhythm disturbance in the mitral valve prolapse is associated with a disorder of the electrophysiological capabilities of the heart.
Functional disorders of heart rhythm in the form of primary dysfunction of the electrophysiological properties of the myocardium occur in the absence of visible organic pathology. Characteristic for a different congenital and acquired pathology, for example, an elongated QT interval syndrome. Also, supraventricular tachycardia can cause FJ, especially in the development of premature ventricular ejaculation syndrome.
Sometimes peripheral and central disorders of hemodynamics cause fibrillation of the ventricles. Allocate idiopathic forms of pathology, which are mostly found in young people. Nevertheless, most of the fibrillations and the sudden death associated with them account for postinfarction states. Moreover, during the first year after an infarction, this risk is 5%.
Video: Cardiopulmonary Resuscitation (CPR): Compression & Defibrillation – Emergency Medicine | Lecturio
Types / photos of ventricular fibrillation
Doctors FZ are conditionally divided into primary, secondary and late.
- Primary occurs in the first two days after a myocardial infarction. In 80% of cases, pharyngitis develops within 12 hours due to an enlarged infarction.
- Secondary PF develops on the backdrop of left ventricular failure. Also, cardiogenic shock may occur, especially after myocardial infarction.
- Late FG may occur within two days after a heart attack and the risk of its development persists for 2-6 weeks. At the same time, in 40-60% of cases, death occurs precisely in the later fibrillation of the ventricles.
At ECG, ventricular fibrillation is divided into two types, which, in the process of development of the pathological state, pass into one another.
- Large-wave fibrillation - corresponds to primary and secondary FJ, as well as to the first two stages of the separation of Carl J. Wiggersen. When it is determined, large, narrow waves, going with a frequency of 300 to 600 per minute.With this type of ECG, the forecast is favorable and the patient can be provided with effective medical assistance.
- Small-wave fibrillation - corresponds to late FG, as well as the third and fourth stages of the pathological process.Under it, the waves become expanded with a lower and non-uniform amplitude. The heart rate first increases by more than 600 per minute, and then gradually decreases to 400 times per minute.
Complications of ventricular fibrillation
Fibrillation of the ventricles is dangerous because of the lack of coordinated movements of the heart organs, which begin to contract shredder. As a result, the main function of the heart - to work with a pump - is not fulfilled. Because of this, severe hemodynamic disturbances arise, leading to death in extreme cases.
Lack of blood circulation for only 5-6 minutes results in irreparable consequences.
In addition to the fatal outcome of the FG, it can cause a number of other serious complications:
- Thromboembolism of large vessels, which leads to the development of stroke and ischemic disorders in other organs.
- Dilatational form of cardiomyopathy, in which the expansion of the cavities of all parts of the heart is observed.
There are also postremunization complications, the severity of which depends on the measures taken during emergency care. For example, there may be rib fractures or aspiration pneumonia. There may be arrhythmias, if they were not there before, or a more frequent recurrence of the earlier ones. Some patients have neurological complications in the form of anoxic encephalopathy.
It is worth noting that neurological disorders may be absent when unconsciousness is up to 72 hours. At the same time prognostically unfavorable is the duration of the coma for more than 3 days.
Diagnosis of ventricular fibrillation
Electrocardiography is a commonly used method for diagnosing arrhythmic conditions. During ventricular fibrillation using ECG, it is determined:
- Normal QRS complexes are replaced by chaotic, multi-directional waves of large and small amplitudes.
- When trembling the ventricles, the waves remain rhythmic, while flickering, there is no rhythm.
- The pin R is practically not defined.
If the FJ arose against a background of myocardial infarction, blockade of the AB-node or other cardiac pathology, then the signs on the ECG will be similar.
In some cases, the ECG is not sufficiently informative or it is necessary to clarify the location of the ectopic focus, then additional research methods are used.
- The ultrasound of the heart is done by echocardiography, when on the screen of the device you can see the size of the walls of the cells, their contractility.
- Holter monitoring is suitable for specifying the diagnosis when arrhythmia attacks failed to fix. The diagnostic time is from one day to one week.
After stopping fibrillation, it is important to know the cause of the pathology. This is especially needed in the case of developing arrhythmia in the face of complete health. For this purpose, various laboratory tests and diagnostic methods are used. First of all, the thyroid gland is checked, for which the ultrasound of the organ is done. Also, according to testimony, tests for rheumatic factors, electrolyte levels and general blood parameters can be given.
Treatment of ventricular fibrillation
It begins with providing the patient with urgent care, with every second important. At this stage, it is necessary to restore the work of the heart, for which, as a rule, cardiopulmonary resuscitation is used. In the future, the treatment is aimed at preventing possible relapses.
Emergency help with sudden cardiac arrest
Since ventricular fibrillation is capable of causing a cardiac arrest in a short time, it is worthwhile to know the measures of assistance. If in a street or in any other place a person suddenly became pale, lost consciousness and fell without visible signs of life, then you should follow the instructions for urgent care when suddenly stopping the heart:
- Quickly contact an ambulance.
- Sharply hit the area of the sternum, which in some cases helps to "start" the heart.
- In the absence of pulse, it is necessary to begin to do an indirect heart massage with artificial ventilation of the lungs.One resamateur should perform 2 breaths and 15 pressure on the sternum. Two reanimators are made 1 to 5, respectively.
If the ambulance with the patient will go for a long time, and it will be possible to deliver faster with your course, you should prefer the first variant of transportation. This is due to the fact that all reanimobiles have the necessary equipment to support human livelihoods. Therefore, even fast delivery by own transport can threaten the loss of a person.
Begins to be conducted at the pre-hospital stage and aimed at providing organs with blood and oxygen. Performed by a resuscitation brigade of ambulance using an electric defibrillator. Far is not always the time to evaluate the state of the heart by ECG, so cardioversion starts "blind". Depending on the results, defibrillation can reach 360 J.
If the work of the heart does not recover or after a short time begins to begin fibrillation, the adrenalin is started according to the scheme:
Lack of result from the ongoing resuscitation is an indication for the introduction of lidocaine. In some cases, it is replaced by novocainamide or brethel, a third-class antiarrhythmic agent. In acute myocardial infarction, the introduction of esmolol or propranolol is recommended. If there is a high probability of developing arterial hypotension, then in return for the antibiotic it is necessary to administer amiodarone.
Secondary prophylaxis of ventricular fibrillation
It is concluded in the treatment of those diseases that can cause FJ. If it concerns the coronary heart disease, then all the measures to prevent myocardial ischemia are good for preventing the development of fibrillation.
Secondary prophylaxis involves referral to a doctor for any violations of heart rhythm. In these cases, the appointment or correction of already taken antiarrhythmic drugs helps. Also, more aggressive drugs that can restore normal heart rhythm can be used.
This terminal condition requires timely medical attention. In the absence of a medical brigade, an indirect heart massage with artificial ventilation of the lungs is performed. Emergency workers make defibrillation of the ventricles by electric current and administer appropriate drugs. In parallel, a control ECG is made. If after the third level the work of the heart is not restored, then trachea is intubated and intravenous adrenaline is administered. In some cases, the drug is injected into the trachea or directly into the heart. Other arrhythmias may also be used during resuscitation: lidocaine, novocainamide, ornide. If the reanimation measures did not turn out to be effective and the patient failed to return to life, then they would be stopped 30 minutes from the beginning.
While left ventricular failure has been the subject of intensive discussion for decades, right ventricular heart failure, as a rule, remained with minimal attention. Indeed, the right half of the heart for a long time was considered relatively passive channel for blood flow between systemic and pulmonary blood circulation, respectively, its frustration was considered relatively not difficult.