Ventricular fibrillation - a peculiar condition of the body, in which the broken heart rhythm so that threatens the life of the patient.At the moment of ventricular fibrillation, there has been rapid, uncoordinated and inefficient ventricular contractions that result from multiple chaotic electrical impulses. This pathological condition characterized simply shake them without coordinated contraction, as in atrial fibrillation.During this process does not work the cardiac output of blood, so the chaotic contraction of the ventricles - is practically a cardiac arrest, and if it does not stop, there comes death.Inadequate blood flow in the myocardium on the background of ischemic heart disease, especially myocardial widespread is the main cause of ventricular fibrillation, and among other reasons, its occurrence is considered to hypokalemia and shock.
Typically, this pathological process results in the loss of consciousness, and without appropriate treatment causes sei
ventricular fibrillation can be expected to diagnose on the basis of sudden fainting, neproschupyvanii pulse and heart rate, and the absence of pressure.Therefore, only the results of the ECG can absolutely confirm the diagnosis.
the basis of urgent measures is heart and lung resuscitation and cardioversion.In the future, the treatment continues with the help of drugs, to maintain a normal heart rhythm.
In the event of such a pathological condition after myocardial infarction without heart failure and shock, an urgent cardioversion has a positive effect with a favorable prognosis in 95% of cases.And while having significant heart damage, cardioversion success is characterized by only 30% of cases.
Ventricular fibrillation causes
Ventricular fibrillation is caused by ventricular contractile randomly at up to 450 beats per minute.This type of arrhythmia is dangerous and requires immediate assistance in the form of defibrillation to prevent heart failure.
The causes of chaotic heartbeat in many patients is any cardiac pathology, as well as other violations of extracardiac character.Such cardiac abnormalities primarily in acute ischemic heart disease is a pathology of blood circulation in coronary arteries, or acute myocardial infarction.Furthermore, sudden death in ischemic heart disease accounted for 46% of men and 34% of women, and this pathological condition is observed mainly in the first twelve o'clock acute myocardial infarction.Also, the risk of this disease is seen in patients who have suffered myocardial infarction with the presence of Q waves as a result of paroxysmal ventricular tachycardia.
Hypertrophic cardiomyopathy can lead to ventricular fibrillation, which affects mainly the young generation after them intense stress of a physical nature.At the time of cardiac arrest in this patient group recorded polymorphic ventricular tachycardia form that goes into fibrillation.At the same time we must not forget that the fainting and hemodynamic disturbances can cause any form of supraventricular tachycardia, a rhythm having a portion of the ventricles.
Almost 10% of resuscitated patients make a diagnosis of cardiomyopathy with dilatation of character, which contributed to the formation of ventricular fibrillation.
The formation of this condition is also influenced by the RV cardiomyopathy, Brugada syndrome and elongated QT.Harbingers of ventricular fibrillation in these syndromes is a VT type pirouette, while RV cardiomyopathy - a form of monomorphic VT.
among heart valve defects in the formation of the pathological process is isolated aortic stenosis of congenital and acquired etiologies.But with such a heart disease as mitral valve prolapse with significant frequency of arrhythmias, ventricular fibrillation observed quite rare and mostly due to violations of the properties of the heart muscle.
among specific cardiomyopathies that cause chaotic contraction of the ventricles, especially on the background isolated cardiomyopathy and sarcoidosis inflammation.
most rare causes of this disease can be considered a poisoning cardiac glycosides, violations of electrolyte metabolism, shock from electric shock, hypothermia, acidosis and hypoxia, cardioversion, coronary angiography, a side effect when taking different groups of drugs such as sympathomimetic, barbiturates, narcotic analgesics, antiarrhythmic agents of the first class, the phenothiazines and drugs for anesthesia.
The development of ventricular fibrillation affects some of the factors that reduce the electrical stability of the heart muscle.These factors include: the increased size of the heart, existing centers of degeneration and sclerosis in the myocardium and conducting system, as well as increased sympathetic activity.
Almost 90% of patients cause ventricular fibrillation and ventricular tachycardia is much rarer, ventricular arrhythmia.
Ventricular fibrillation symptoms
characteristic symptoms of this condition consists of two forms of ventricular fibrillation: the primary and secondary flows flowing.The first form develops when heart disease without specific manifestations of insufficient blood flow and the secondary - in critically ill, for which the expressed stagnation inherent lack of blood flow and symptoms of cardiogenic shock.In the secondary form of isolated atonal, which occurs very rarely and appears not breathing, and pressure, as well as other disorders in a very difficult way.
forerunners of pathological states are appearing early beats and plural nature of the group, as well as paroxysmal ventricular tachycardia.
Usually, symptomatic picture of ventricular fibrillation is characterized by rapid start.In the beginning, determined whirling head and weakness, then twenty seconds later the patient loses consciousness, and forty-five seconds, he appeared spasms and involuntary urination character.The absence of heart sounds, and begins apnea, in which the patient is in a state of shock with the absence of pulse, blood pressure and sudden appearance of pallor of the skin and mucous membranes.After performing a few breaths, there comes death.
electrocardiographic ventricular fibrillation is characterized by irregularly spaced waves that have different amplitude of shapes and sizes.
Since chaotic contraction of the ventricles represents the symptoms of sudden cessation of blood circulation and death of clinical character, while still observing the pupil, who did not react to light.In addition, it is impossible to test the pulse of the arteries, carotid and femoral like.If it is impossible to restore the activity of the heart rhythm for four minutes, irreversible processes in the central nervous system and other organs.
whole character of complications and outcome of disorderly heartbeat depends on the correct and timely provision of resuscitation on the heart and lungs.
possible complications of aspiration pneumonia may be the nature and lung injury during rib fractures during resuscitation.And during cardiac ischemia develops cardiac muscle, and after coronary circulation is restored - transient myocardial dysfunction.Neurological complications characterized by the appearance of seizures and coma, leading to even decortication.If the duration of coma for more than three days, to ensure the survival and recovery of brain activity is almost impossible, as a rule, always a bad prognosis.
Ventricular fibrillation ECG
It is difficult to distinguish between cardiac arrest from ventricular fibrillation due to the similarity of symptomatic manifestations.Thus, the formulation of an appropriate diagnosis is on the basis of ECG data.
electrocardiographic ventricular fibrillation is characterized by the disappearance of ventricular complex shape and the appearance of waves of different width and height with pointed or rounded upper and lower ends.It is also characterized by a wave nedifferenziruyuschimi teeth.This heart rate reaches three hundred beats per minute.The amplitude of these waves consists of two specific forms of ventricular fibrillation: krupnovolnovuyu and melkovolnovuyu.In addition, there is no isoelectric interval as separate waves into each other to form a bizarre curve.
Thus, the basic ECG signs of ventricular fibrillation are the absence of typical curve with familiar differentiated teeth T, S, R, Q, P;registration instead of small and different in magnitude with the uneven shape of the waves of atrial fibrillation;different distance between wave peaks;the absence of a clear form of contour lines.Their causes - pathological and outlook - poor.There may come a defibrillation.
Ventricular fibrillation treatment
To prevent biological death is necessary to carry out emergency measures in the first four minutes of ventricular fibrillation.When neproschupyvanii pulse on such major arteries like the carotid or femoral, begin to carry out chest compressions with ventilation (artificial lung ventilation) to maintain blood flow to the desired level, which is able to provide the heart and brain of oxygen, and restore them work throughspecific therapies.
in the ICU, which allows you to continually monitor heart rate via ECG, you can immediately determine the shape of the heart to stop and start treatment.For the most effective method of treatment of ventricular fibrillation in the first seconds of holding therapy is a fast electrical impulses.Very often such therapy, especially in primary forms, turns out to be one of the most effective methods of resuscitation.In addition, with this electro-therapy within the first minute of ventricular fibrillation, which appeared for the first time, recovering heart rate almost 75% of patients, and on the third or fourth minute, without a cardiac massage and artificial ventilation of the lungs, but in somecases.
If this treatment fails, then to normalize metabolic processes in the heart muscle continues, and sometimes are just beginning to perform chest compressions and ventilation using oxygen.If you have two or even three discharges defibrillyatornyh heart rhythm can not be restored, then spend intubating the patient to transfer to an artificial breathing apparatus.Then immediately administered intravenously Sodium bicarbonate 200 ml bolus, or every ten minutes, 50 mL, until circulation is satisfactory with the possibility of controlling the pH of the blood, to prevent acidosis amid clinical death.In addition, all medications administered better by 5% p-D glucose, which is filled with a system to drip.
To increase the effectiveness of treatment of ventricular fibrillation, electrical impulses, appoint an emergency administration of epinephrine hydrochloride inside the heart, which is at the heart gets a massage from the ventricular cavity into the arteries.However, we must not forget that such intracardiac injection of the drug may result in the development of pneumothorax, vein damage, various extensive bleeding into the heart muscle.Then, epinephrine hydrochloride can be administered intravenously at intervals of five minutes.Furthermore, as the stimulation can be used, and other drugs such as Mezaton or norepinephrine.
When treatment failure ventricular fibrillation electrical pulses can be entered Ornid, obzidan, Inderal, lidocaine, procainamide, or Novocaine.However, ventricular fibrillation whole drug therapy is ineffective, in contrast to the use of electrical pulses.But, nevertheless, continue to cardiac massage and artificial ventilation of the lung, and after two minutes was repeated defibrillation.If after her heart stops, enter the Calcium chloride and sodium lactate, and deffibrillyatsiyu to perform recovery of the heart or of signs by which one can diagnose brain death.At that time, when there will be visible a distinct self-pulsation of large arteries, is stopped to hold a closed heart massage.
important moment in the therapeutic treatment of ventricular fibrillation is considered clock surveillance of the patient and all necessary measures in order to prevent repeat attacks.In some moments, when the equipment is not available for treatment of electrical impulses may use conventional voltage of the power supply from 127 V to 220 V. Sometimes holding punch in the atrial region of the heart rate recovers.In some cases, an inordinate contraction of the ventricles occurs very often, so have to resort to defibrillation to twenty times a day, but it may not produce a positive result even with the simultaneous introduction of anti-arrhythmic drugs.Therefore, in this case, recurrent ventricular fibrillation is eliminated only after implantation of an artificial cardiac pacemaker.
Typically, ventricular fibrillation is characterized by a poor prognosis in case of failure of the electrical impulses therapy as medical treatment is almost ineffective.Therapy electrical pulses gives a positive result only if krupnovolnovoy form of pathological process, while melkovolnovoy - outlook negative.
Ventricular fibrillation Emergency
This pathological condition is considered to be the main cause of sudden death and is characterized by advancing common, more than three hundred beats per minute, random, ventricular hemodynamic activity.Symptoms are very similar to asystole.An electrocardiogram indicated a chaotic shimmering waves.Ventricular fibrillation is characterized by such a condition in which oxygen is consumed by high cardiac muscle and heart like a "swarming clam."
Help with urgent measures if ventricular fibrillation is of an urgent resuscitation, which is able to provide adequate ventilation and normalize blood circulation, eliminate the cause until the cessation of breathing and blood circulation.
First of all, you can dramatically make a punch in the lower third of the sternum, then there is cause precordial thump twenty centimeters above the chest, if not close to a defibrillator.Then call the resuscitation team and start emergency measures for the implementation of indirect heart massage and artificial ventilation of the lungs in order to prepare the patient for defibrillation, which will hold a discharge in 200 J.
While maintaining the pathological process in the heart of conduct repeated defibrillation with increasing discharge to three hundredand, in some cases, this charge should be repeated with the increase to 360-400 George. It is important to remember that if you just start treatment with electric pulses with high levels, it can cause complications postkonversionnogo character.
In the future, the ineffectiveness of such therapy begin to intravenous or intracardiac administration of lidocaine, which allows us to shorten the interval between the Q wave and the T and reduce the defibrillation threshold or obzidan, reduces refractoriness in different parts of the myocardium.Again, a refresher defibrillation.
Saving chaotic contraction of the ventricles can now enter intravenous sodium bicarbonate;Lidocaine intravenously at two milligrams per minute, or 100 mg bolus every ten minutes;