Atrial fibrillation
Atrial fibrillation is a form of disturbance of the normal contractile activity of the heart caused by disorganization of the electrical activity of the atria. Atrial fibrillation there is a sharp increase in the frequency of cardiac contractions to 600 beats per minute, as well as a discrepancy in the number of atrial and ventricular contractions.
Among all possible types of rhythm disturbance, cervical arrhythmia accounts for 30%.The main risk group are men over 60 years old, suffering from organic pathology of the cardiovascular system. For the development of atrial fibrillation, sex is also important - men are 1.7 times more likely than women.
Constant atrial fibrillation without adequate antiarrhythmic therapy provokes serious cardiovascular disorders and is fraught with the development of cerebral stroke and thromboembolic complications.
Atrial fibrillation of the heart
Normally, the activity of the heart is its ability to constantly and regularly contract. The contractility is the response of muscle tissue to electrical impulses that flow through the so-called "cardiac conduction system."The term "normal heart rhythm" refers to the sinus rhythm, since the generation of electrical impulses occurs precisely in the sinus node. Normally the first contraction of atrial fibers, and then electrical impulses are carried out to the ventricles, causing their involuntary contraction.
If paroxysm of atrial fibrillation occurs, ineffective atrial contraction occurs, and blood is injected into the ventricles in a passive manner and in insufficient volume. Thus, there is a regular absence of ejection of blood into the aorta.
Atrial flutter in the ventricles also receives insufficient blood volume, but it happens for a different reason. When atrial flutter is constantly in systolic state, that is, there is practically no diastolic phase. Since the atria are in a compressed state, the blood enters them in a limited volume.
Thus, with any form of atrial fibrillation, conditions are created for the development of ischemic events in all organs and systems, which is clinically manifested by cerebral strokes, ischemic heart disease and acute coronary syndrome. The extreme manifestation of cardiac output disturbance is arrhythmogenic shock.
Atrial fibrillation of the cause of
The most common etiological factors in the onset of atrial fibrillation are diseases of the cardiovascular system: hypertensive disease, chronic ischemic heart disease, cardiac malformations resulting from rheumatic disease, cardiomyopathy.
During cardiosurgical operations and / or in the early postoperative period, attacks of paroxysmal atrial fibrillation often occur, and in most cases it passes without medication.
Frequent use of caffeine-containing beverages and medicines can lead to the development of atrial fibrillation, since the coffee house exerts a potentiating effect on the contractility of the heart muscle.
The systematic use of alcohol negatively affects the heart rhythm, as it causes alcoholic cardiomyopathy and intoxication.
In people with thyroid pathology with concomitant signs of hyperthyroidism, the incidence of atrial fibrillation is about 25%.This high rate is due to the potentiated effect of catecholamines on the excitability of the myocardium of the atria.
When taking certain groups of drugs( diuretics, atropine and adrenaline), the risk of developing rhythm disturbances increases, as these drugs affect the functioning of the heart and disrupt the balance of microelements involved in the generation of electrical impulses.
At a young age, the most common cause of atrial fibrillation is the congenital prolapse of the mitral valve.
Diseases accompanied by a rise in temperature, provoke a malfunction in the functioning of the autonomic nervous system, and heart palpitations occur, which can lead to disruption of the sinus node.
Acute lack of electrolytes in the body leads to violations of automatism and the conductive system of the myocardium.
The nervous system has a great effect on the onset of atrial fibrillation. With the activity of various parts of the nervous system, various types of arrhythmia are formed. There is a vagal and hyperadrenergic variant of atrial fibrillation. The first type is more common among the male half of the population and the provocation of an attack is a horizontal position during sleep, overeating and wearing tight clothes. The second type affects women more often, and there is a clear correlation between the occurrence of an attack and emotional stress.
There is also an idiopathic version of atrial fibrillation, in which it is impossible to reliably determine the cause of the onset of an attack. This form of arrhythmia accounts for 30% of cases.
Atrial fibrillation symptoms
The degree of clinical manifestations of any form of atrial fibrillation depends on the heart rate and also on the degree of ventricular dysfunction. There are cases when a person does not feel an attack of atrial fibrillation in any way, but in most situations, developed clinical symptoms develop. The most seriously ill patients suffer a tachysystolic form of atrial fibrillation.
Patients are difficult to tolerate the paroxysmal type of atrial fibrillation, and with its further transformation into constant atrial fibrillation, many patients cease to pay attention to the symptoms of heart rhythm disturbances.
The most common complaints of patients with an attack of atrial fibrillation is a feeling of rapid heartbeat, a feeling of shortness of breath, dizziness, discomfort in the heart, sweating and shivering. There is a clear correlation between the appearance of these symptoms and provoking factors, in which the role is played by excessive physical activity, psychoemotional arousal, smoking and alcohol abuse.
In an objective study of the patient, attention is drawn to the sharp increase in the pulse and the increase in blood pressure in combination with the weakness of pulse filling. Auscultative changes are manifested in the uneven sonority of tone I.
The attack of atrial flutter is manifested in the sensation of rapid heartbeat, sudden dyspnea short of choking, pulsation of superficial veins in the neck and discomfort behind the sternum.
At occurrence of a ciliary arrhythmia at the patient with an available defect of heart on the foreground clinical symptoms of a heart failure leave.
Usually, the correct diagnosis is sufficient to conduct an objective examination of the patient with a mandatory pulse palpation and auscultation of the heart, but in order to reliably determine the form of atrial fibrillation must perform Holter monitoring, in which it is possible around the clock to monitor changes in activity of the heart. Additional methods for examining a patient with atrial fibrillation are: ultrasound examination of the heart( assessment of heart size and valve system condition), blood test for electrolyte composition and thyroid hormones.
Atrial fibrillation of form
The nosological form of "atrial fibrillation" is a complex concept involving two main mechanisms of cardiac abnormalities - flutter and atrial fibrillation. Both these concepts were combined, because they have a similar etiological nature, clinical manifestations and are often observed simultaneously in the same patient.
principal difference between these options fibrillation is that atrial fibrillation is not specific to a coordinated atrial contraction, resulting in an abnormal rhythm of ventricular contraction, while flutter is observed only a significant acceleration of the contractility of the atrial and ventricular contractions no violations.
depending on heart rate, atrial fibrillation is divided into embodiments: normosistolichesky( heart rate of 60-90 beats per minute, heart rate but incorrect) tachysystolic( combination palpitations than 90 beats per minute with incorrect rhythm of cardiac contractions) and bradisistolichesky( Heart rhythm irregular and slowed down - less than 60 beats per minute).
In turn, atrial flutter can be regular when every second or third atrial contraction is accompanied by contraction of the ventricles, and irregular, in which a chaotic uncoordinated atrial and ventricular contraction occurs.
In the first episode of atrial fibrillation, the first-time form of fibrillation takes place, and if the episodes recur, then this condition is regarded as a recurring form.
There common variants of atrial fibrillation: paroxysmal( duration of clinical manifestations of not more than 48 days, and the attack ends independently), persistent( seizure duration exceeds 7 days and needed in coupling via medicines and cardioversion) and constant( restoring normal sinus rhythmIs not possible).
Paroxysmal atrial fibrillation
The first signs of atrial fibrillation in a patient are most often the paroxysmal form of atrial fibrillation, which can later become a permanent form. The time of transition from the paroxysmal form to the constant depends on the individual characteristics of the organism and the state of the heart muscle.
Paroxysm of atrial fibrillation is a sudden onset of rapid heartbeat, accompanied by weakness, shortness of breath, paleness of the skin, a feeling of inner tremor and excessive sweating. When tahisistolicheskoy form often in patients there is a short-term loss of consciousness as a result of impaired cerebral circulation. The above symptoms occur after exposure to the body of provoking factors( excessive physical activity, smoking, stress) or against the background of complete well-being. The first episodes of paroxysmal arrhythmia are short-lived and do not need a medical correction.
Frequent bouts of worsening the patient's quality of life and accompanied by thrombolytic complications require antiarrhythmic treatment, which is not only symptom relief, but also systematically taking antiarrhythmic drugs and medications to correct heart rate.
Paroxysmal atrial fibrillation is dangerous for its complications, among which the most common are: cardiogenic shock with a sharp drop in blood pressure, congestive heart failure and pulmonary edema, impaired coronary and cerebral circulation, asystole, and thromboembolism, which develops within two days after the onset of an attack of atrial fibrillation.
cupping of paroxysmal atrial fibrillation is carried out by intravenous procainamide( 15 mg / kg), verapamil( 0.15 mg / kg) or digoxin( 0.25 mg), and in the absence of effect of drug therapy used method transesophageal atrial electrostimulation.
Atrial fibrillation treatment
All therapeutic measures to help patients with atrial fibrillation attacks directed at relief of clinical manifestations, as well as the prevention of possible complications, thereby reducing the risk of death.
indications for urgent hospitalization in hospital are first identified episode of atrial fibrillation, not cropped attack paroxysmal atrial fibrillation, occurrence of complications and adverse reactions resulting from the application of medicines, the combination of permanent atrial fibrillation and congestive heart failure with high tachycardia.
In the treatment of episodes of atrial fibrillation, two main methods are followed: restoring the right sinus rhythm of cardiac activity or regaining control over the heart rate with preserved atrial fibrillation. Each of these methods has not only advantages, but also drawbacks. The disadvantage of the first variant is the manifestation of adverse reactions to the administration of medications in the patient, as well as the risk of thromboembolism. When monitoring the heart rate while maintaining atrial fibrillation, patients need long-term anticoagulant therapy.
In a situation where the onset of atrial fibrillation is not accompanied by clinical manifestations and is an accidental finding during a planned examination of a patient, it is necessary to adhere to expectant management for 72 hours, while constantly monitoring hemodynamic parameters. In most cases, such attacks of atrial fibrillation pass independently. In this period of waiting, it is enough to prescribe a calming therapy to the patient.
Sinus rhythm recovery is performed using the antiarrhythmic drug groups and electrical cardioversion. It should be borne in mind that the restoration of rhythm with uncontrolled heart rate is impractical.
to reduce heart rate are various groups of drugs in atrial fibrillation: B-blockers( Propranalol intravenously at a dose of 0.15 mg / kg of atenolol 50 mg per os), calcium channel blockers( verapamil intravenously 0.15 mg / kg, daily AmiodaroneA dose of 800 mg in tableted form), cardiac glycosides( Digoxin intravenously 0.25 mg).
On the background of antiarrhythmic therapy necessarily carried out monitoring of blood clotting, and if necessary apply anticoagulant( Acetylsalicylic acid 365 mg per day)
to restore normal sinus rhythm is preferable to use propafenone and quinidine( loading dose of 300-600 mg), but it should be taken into account, That they can provoke an increase in heart rate as a result of the transition of atrial fibrillation into flutter. Prokainamide is widely used in a dose of 5-15 mg / kg intravenously drip to restore the rhythm.
The second in effectiveness of arresting an attack of paroxysmal atrial fibrillation after quinidine is Rhythmelen. It is necessary to observe a certain loading system for the use of this antiarrhythmic drug: the initial dose is 0.2 g, after an hour, electrocardiographic monitoring is performed and in the absence of positive results, the patient is given 0.1 g each hour, thus bringing the dose to 1 g. Absolute contraindicationsFor Rhythm Mylene use are glaucoma and prostate adenoma.
In case of an attack of atrial fibrillation in a patient suffering from congestive heart failure, the drug of choice is Amiodarone( loading dose is 800-2000 mg per day).A significant advantage of this drug is its ability to control the rhythm of ventricular contraction, which is very important in this form of atrial fibrillation, like atrial fibrillation.
Indications for conducting electrical cardioversion are a number of factors:
- a combination of paroxysmal atrial fibrillation with acute coronary syndrome;
- occurrence of an attack of atrial fibrillation on the background of pronounced arterial hypotension and progressive phenomena of heart failure;
- lack of positive effect from the use of medicines;
- individual intolerance to antiarrhythmic drugs or the presence of contraindications to their use;
- the available positive results from the use of a cardioversion in the anamnesis.
There are absolute contraindications to the use of electrical cardioversion, which can lead to complications and even death: infectious diseases in the acute period, an overdose of cardiac glycosides, heart failure in the stage of decompensation.
Before performing electrical cardioversion routinely need to prepare the patient for manipulation: for five days before the expected cardioversion should abolish diuretics and cardiac glycosides, for the prevention of hypokalemia assigned intravenous administration of a mixture containing potassium, insulin and glucose, amiodarone at a dose of 800 mgPer day, the use of anticoagulant therapy, the implementation of premedication( Promedol 1 ml of a 2% solution in combination with Atropine 1 ml 0.1% solution subcutaneously).
For the conduct of cardioversion, the correct location of the electrodes is important - the first in the projection of the apical impulse, the second in the projection of the second intercostal space along the parasternal line on the right. The power of the first digit should be 100 J, and in the absence of a positive effect, it must be increased to 360 J.
After successful arrest of an attack of atrial fibrillation, it is recommended to carry out supporting antiarrhythmic therapy, that is, to select an effective dose of an antiarrhythmic drug that the patient will take daily. Sometimes, to prevent recurrence of atrial fibrillation, it is enough to take one antiarrhythmic drug, but with the existing concomitant cardiac pathology, a comprehensive approach to treatment with several drugs of different groups is recommended. It is possible to select an antiarrhythmic drug based on the subjective feelings of the patient, but there is a more effective way of selecting a drug in the treatment of atrial fibrillation. For this, serial testing of the drug is used in transesophageal atrial stimulation. That is, artificially created arrhythmia attacks and determine the dose of the drug, which can effectively eliminate the manifestations of an attack. If none of the drugs is effective, the patient is recommended surgical treatment of atrial fibrillation.
There is also an effective surgical method for the treatment of atrial fibrillation, which is used in cases of poor tolerance of paroxysmal atrial fibrillation, refractoriness to antiarrhythmic drug therapy and recurrence of thromboembolism. The main methods of surgical treatment are: catheter ablation and implantation of a pacemaker.
Catheter ablation is a minimally invasive operation, during which the surgeon disconnects the fused fibers that are the source of rhythm disturbance, using a catheter( laser, electric or cold).
Pacemaker is a device for artificial pulse generation, which is small in size and located directly under the skin. Wearing a pacemaker requires compliance with a number of conditions: the patient should not be near electrical appliances, the patient is not allowed to conduct instrumental survey methods based on the use of magnetic fields( magnetic resonance imaging).
The effectiveness of treatment of the constant form of atrial fibrillation depends on the correction of the heart rate and keeping it at a normal level( no more than 90 beats per minute).The main groups of drugs for heart rate control in this situation are: calcium channel blockers, B-blockers and cardiac glycosides.
The daily dose of Digoxin is 0.125-0.375 mg per os and its area of application is a constant form of atrial fibrillation in combination with congestive heart failure.
B-blockers( Propranolol in a daily dose of 80 mg and Metoprolol 25-500 mg) are prescribed to patients with persistent arterial hypertension, ischemic heart disease in combination with a constant form of fibrillation.
Calcium antagonists( Verapamil 120-360 mg per day) are effective in atrial fibrillation, which occurs against the background of bronchial obstructive syndrome and diabetes mellitus.
Currently, Amiodarone is the most effective and convenient to use antiretroviral antiarrhythmic drug. Due to its slow elimination from the body, it is necessary to follow a specific scheme of application, which implies initial intake in high doses, and further use in a maintenance dosage: in the first week of use, the daily dose is 0.6 mg, in the second week, a sufficient daily dose is 0,4 mg, and the maintenance dose is 0.2 mg. The most dangerous side effect of taking Amiodarone is fibrosing pulmonitis, the development of which is considered a direct indication for drug withdrawal.
The so-called etiotropic therapy is of great importance in the treatment of atrial fibrillation, which implies the treatment of a disease that caused the rhythm disturbance( surgical treatment of cardiac malformations, correction of thyrotoxicosis).
Paroxysmal form of atrial fibrillation is characterized by pronounced manifestations of autonomic dysfunction, in connection with which there is a need for the use of psychotropic drugs during the attack: Diazepam - 5 mg, Nosepam - 10 mg.
Traditional medicine offers its effective prescriptions for the prevention of attacks of atrial fibrillation, among which the most common are decoctions of viburnum and dill seeds, as well as alcohol tincture from the yarrow. All these recipes contribute not only to the normalization of the heart rate, but also to maintaining blood pressure at a normal level.
For preparation of the decoction of broth it is necessary 200 gr. Vinas boil in the same volume of water for 20 minutes and allow to infuse for about 12 hours, then take in place of tea twice a day for 100 ml. Decoction of dill seeds is prepared in a similar way in proportion of 1 part of the seeds to 3 parts of boiling water. Take the broth 3 times a day before meals, 50 ml each.
To prepare an alcohol tincture of yarrow, you need 500 gr. Chemist's collection pour 500 ml of alcohol and let it infuse for 10 days in a cool place in a sealed glass dish. Take infusion in the morning on an empty stomach for 1 tsp.
A diet designed by nutritionists specially for this category of patients is of great help in the prevention of recurrence of atrial fibrillation. Prohibited products include: strong coffee, alcoholic beverages, dark chocolate and sweets. It is recommended daily use of food products such as: dried fruits, citrus fruits, nuts, cranberries and vegetable oils.
The prognosis for atrial fibrillation may be favorable, provided the correct selection of an antiarrhythmic drug and its systematic admission, as well as a satisfactory condition of the ventricular myocardium. Antiretroviral therapy is lifelong and the only indication for the abolition of an antiarrhythmic drug is the appearance of adverse reactions or the lack of effect from the application. In this situation it is recommended to hospitalize a patient in a hospital for the selection of antiarrhythmic treatment under constant monitoring of instrumental and laboratory methods.
