Have you ever had moments when your heart began to beat chaotically? Or, on the contrary, slowed down? This causes a feeling of fear and anxiety, makes you think about going to the hospital. Doctors have a definition for any condition, including this one. Fibrillation is a form of heart rhythm disturbance. In cardiological practice, such cases are not uncommon, so we will talk about them today.
Definition and prevalence
There is also a scientific definition for this behavior of the heart. Fibrillation is a tachyarrhythmia, which is combined with the chaotic activity of the electrical impulses of the atria. Their frequency can reach seven hundred beats per minute, and at such a speed, coordinated contraction becomes impossible.
Fibrillation is one of the most common forms of rhythm disturbance. It can be reliably determined only by the results of electrocardiography. There are characteristic signs: the absence of sinus rhythm, the appearance of f-waves (atrial tremor). The frequency of contractions depends on the properties of the atrioventricular node, as well as the activityautonomic nervous system in combination with drugs.
Experts associate this disease with an organic lesion of the heart muscle. Chaotic contractions of the heart lead to circulatory disorders and the risk of embolism. The high lethality of this disease is associated with this phenomenon.
Classification
The following forms of atrial fibrillation are distinguished:
- First time revealed. This diagnosis is made if the patient has not previously sought medical help for atrial fibrillation.
- Paroxysmal. An attack of flutter lasts no more than a week (usually two days) and passes on its own.
- Persistent. Attacks last more than seven days.
- Long persistent. The attack lasts ten to twelve months, but the doctors decided to restore the rhythm.
- Constant. Atrial fibrillation is observed constantly, but the rhythm was not restored at the initial stages, and then it turned out to be ineffective.
Atrial fibrillation is divided into four classes according to the severity of symptoms:
- Asymptomatic.
- Mild discomfort without disruption.
- Severe symptoms that affect the comfort of life.
- Disability. In this case, the patient cannot take care of himself.
Depending on the pulse rate, doctors distinguish tachy-, normo- and bradysystolic form of the disease.
Risk factors
cardiac fibrillation occurs in patientswho are predisposed to it. It may be preceded by various cardiac problems:
- hypertension;
- heart failure;
- acquired defects of the mitral valve;- congenital malformations of various etiologies.
Dilated cardiomyopathy, coronary heart disease, chronic inflammatory diseases of the membranes of the heart, and tumors play an important role. Paroxysmal atrial fibrillation in people younger than forty can occur in isolation from other diseases.
In addition, there is a list of pathologies that equally affect the appearance of fibrillation, but they are not related to the work of the cardiovascular system:
- obesity;
- diabetes mellitus;
- chronic obstructive pulmonary disease;- increased activity of the thyroid gland.
If the patient has a compromised family history, that is, among close relatives there are people with atrial fibrillation, the chances that the disease will appear in the proband increase by thirty percent.
Pathogenesis
Fibrillation is a chaotic twitching of a muscle, in this case the heart. Organic diseases contribute to structural changes in the anatomy of the heart and cause a violation of the conduction of electrical impulses. This is due to an increase in the amount of connective tissue and subsequent fibrosis. This process progresses, aggravating the dissociation of nerve fibers, therefore, fibrillation also persists.
Doctors are considering several hypotheses about howparoxysmal form of this disease. The most common are the theories of foci and multiple waves. Some scientists prefer to combine both versions, since it is impossible to completely identify the only cause of the disease.
According to the first theory (focal), there are many foci of electrical activity in the myocardium, which are located near large vessels and along the posterior wall of the atria. Over time, they spread to the entire area of \u200b\u200bthe atria. The second theory postulates that fibrillations appear as a result of spontaneous and chaotic conduction of a large number of small waves of excitation.
Symptoms and complications
Paroxysmal fibrillation may be asymptomatic if hemodynamic disturbances are sufficiently compensated. As a rule, patients complain of a feeling of rapid heartbeat, chest pain or discomfort in this area.
Against this background, heart failure progresses, which is clinically manifested by dizziness, fainting and shortness of breath. Sometimes at the time of an attack, patients experience increased urination. Experts attribute this to an increase in the amount of natridiuretic protein.
Objectively, there can be a pulse deficit when the number of heartbeats exceeds the number of pulse waves propagating to the periphery. With an asymptomatic form of fibrillation, the first "bell" may be a stroke.
Long-term atrial fibrillation is complicated by heart failure, thrombosis of large and smallvessels of the heart or brain.
Diagnosis
Fibrillation is erratic frequent contractions of cardiomyocytes. First, the doctor collects an anamnesis of the disease and life, finds out the date of the first attack, the presence of risk factors, and also learns about the medications that the patient is currently taking. Patients do not complain, therefore, this pathology is detected using instrumental research methods. These include ultrasound, 24-hour Holter monitoring and ECG. Fibrillation is manifested by the following specific signs:
- absence of P wave (no sinus rhythm);
- appearance of f-waves of fibrillation;- unequal intervals between R waves.
In the same way, concomitant heart pathologies can be detected: myocardial infarction, arrhythmias, etc. Ultrasound is performed to detect and confirm organic heart pathology, as well as to measure the thickness of the myocardial walls, the volume of the atria and ventricles. In addition, parietal thrombi and vegetations on the valves are clearly visible on the screen.
In addition, after the first episode of fibrillation, the doctor prescribes an analysis of the level of thyroid hormones to exclude its hyperfunction.
Anticoagulant therapy
By this point, the reader already has an idea of why and how fibrillation appears. Its treatment is aimed at eliminating either the etiological factor or leveling the symptoms of the disease.
Anticoagulants, that is, drugs that thin the blood, are prescribed to prevent the formation of blood clots and, as a result, strokes and heart attacks. The most common tablet forms are Warfarin and Aspirin. When prescribing this group of drugs, the doctor takes into account the patient's tendency to thrombosis, the risk of ischemia in the near future, as well as the patient's contraindications to this type of therapy.
It is important to remember that when using anticoagulants, it is necessary to constantly monitor the INR (international normalized ratio). This will allow you to stop the drug in time and reduce the risk of bleeding.
Rhythm control
Cardiac fibrillation is a reversible condition in most cases. If little time has passed since the onset of the attack, the doctor may restore normal sinus rhythm. This can be done with a directed electric shock or antiarrhythmic drugs.
First, the heart rate is reduced or raised to one hundred beats per minute. Then the risk of thromboembolism must be taken into account, so the patient receives anticoagulant therapy for three weeks before the procedure and a month after it. But all this is necessary only if the attack of fibrillation lasts more than two days or its duration cannot be established. If it is known that forty-eight hours have not passed since the onset of chaotic contractions of the heart, or the patient has severe hemodynamic disturbances, then recoveryrhythm is carried out urgently, low molecular weight heparin is administered.
- Electrical cardioversion. This is a rather painful procedure that requires the patient to be immersed in drug-induced sleep. In modern defibrillators, the discharge is synchronized with the R wave on the cardiogram. This avoids accidental ventricular fibrillation. They usually start with a hundred Joules and, if necessary, increase each subsequent discharge by fifty Joules. This is a two phase model. A single-phase discharge is immediately made at two hundred Joules, with a maximum level of four hundred.
- Medicated cardioversion. Drugs that can affect the rhythm of the heart include Procainamide, Amiodarone, Nibentan, and Propafenone.
To prevent recurrence of atrial fibrillation after cardioversion, antiarrhythmic drugs are prescribed, which the patient needs to take for months or even years.
Heart rate monitoring
All known forms of atrial fibrillation involve abnormal heart rate. Therefore, doctors thought out therapy to eliminate this symptom. For this, drugs are used that can reduce the speed of the heartbeat. These include:
- beta-blockers;- calcium channel blockers.
Amiodarone or Dronedarone is prescribed for the ineffectiveness of drugs from these groups. Such therapy can reduce the manifestations of arrhythmia, but it is not able to remove it completely.
Iftreatment is ineffective, doctors sometimes resort to catheter ablation. In order to maintain sinus rhythm, it is necessary to eliminate all excited areas. Using a radiofrequency probe, the cardiac surgeon isolates the trigger areas from each other, preventing the propagation of electrical waves.
There is another method in which the nerve node between the atrium and the ventricle is destroyed. This creates a temporary transverse heart block. This patient is then implanted with an artificial pacemaker that controls the number of heartbeats. The quality of life of such a patient improves markedly, but this does not affect the duration of his life.
Fibrillation after heart surgery
The paroxysm of fibrillation is also possible after surgical interventions on the heart. This is one of the most common complications encountered after such operations. The pathophysiology of this condition differs from that seen in normal patients with atrial fibrillation.
In addition to the usual risk factors, the patient has ionic dissociation, namely a decrease in potassium levels, a decrease in circulating blood volume, mechanical trauma to the heart tissue and atrial edema. All this provokes the activation of immunity in the form of a cascade of reactions of the complement system. There is a release of inflammatory mediators, stimulation of the sympathetic nervous system, as well as a violent oxidative reaction. All this is a trigger factor for triggering atrial fibrillation.
Therefore, the treatment of postoperative complications begins with the correction of all of the aboveproblems. To do this, use beta-blockers, "Amiodarone", steroid hormones and non-steroidal anti-inflammatory drugs.
Forecast and recommendations
A person can avoid such a dangerous diagnosis as atrial fibrillation. The recommendations of doctors are quite simple and transparent. It is necessary to lead a he althy lifestyle, follow a diet, and prevent an increase in blood pressure above one hundred and forty. These simple actions will not only prevent the occurrence of fibrillation, but also help to avoid other heart diseases.
Of course, smoking cessation and reduced alcohol consumption are recommended. In order to strengthen blood vessels, cardiologists are asked to get enough essential fatty acids from food or take fish oil capsules.
Treatment of bacterial and viral infections is best completed, even if subjectively you already feel well.
The risk of stroke in people with atrial fibrillation increases to five percent by age fifty, and to twenty percent by age eighty. Every sixth registered stroke on the planet is observed in patients diagnosed with atrial fibrillation.
