Have you ever had moments when your heart began to beat randomly? Or, conversely, 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. Fibrillation is a form of heart rhythm disturbance . In cardiological practice, such cases are not uncommon, therefore it is about them that we will talk today.
Definition and prevalence
There is also a scientific definition of such heart behavior. Fibrillation is 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 this speed a coordinated reduction becomes impossible.
Fibrillation is one of the most common forms of rhythm disturbance. Reliably it can be determined only by the results of electrocardiography. There are characteristic signs: lack of sinus rhythm, the appearance of f-waves (atrial trembling). The frequency of contractions depends on the properties of the atrioventricular node, as well as the activity of the autonomic nervous system in combination with drugs.
Experts attribute this disease to organic damage to the heart muscle. Random heart contractions lead to circulatory disorders and the risk of emboli. A high mortality rate of this disease is associated with this phenomenon.
Classification
The following forms of atrial fibrillation are distinguished:
- First identified. Such a diagnosis is made if the patient has not previously sought medical attention for atrial fibrillation.
- Paroxysmal. The fluttering attack lasts no more than a week (usually two days) and passes independently.
- Persistent. Attacks last more than seven days.
- Persistent for a long time. The attack lasts ten to twelve months, but the doctors decided to restore the rhythm.
- Constant. Atrial fibrillation is constantly observed, but the restoration of rhythm in the initial stages was not carried out, and then it was ineffective.
According to the severity of symptoms, atrial fibrillation is divided into four classes:
- Asymptomatic.
- Light discomfort without disruption.
- Severe symptoms that affect life comfort.
- Disability. In this case, the patient cannot take care of himself.
Depending on the pulse rate, doctors distinguish a tachy-, normo-and bradisystolic form of the disease.
Risk factors
Cardiac fibrillation appears in patients who are predisposed to this. It may be preceded by various cardiac problems:
- hypertonic disease;
- heart failure;
- acquired defects of the mitral valve;
- Congenital malformations of various etiologies.
An important role is played by dilated cardiomyopathy, coronary heart disease, chronic inflammatory diseases of the membranes of the heart, as well as tumors. The paroxysmal form of atrial fibrillation in people younger than forty years of age can occur in isolation from other diseases.
In addition, there is a list of pathologies that equally affect the appearance of fibrillation, but at the same time they are not associated with the work of the cardiovascular system:
- obesity;
- diabetes;
- chronic obstructive pulmonary disease;
- increased activity of the thyroid gland.
If the patient's family history is compromised, that is, among close relatives there are people with atrial fibrillation, the chances of the disease appearing in the proband also increase by thirty percent.
Pathogenesis
Fibrillation is a jerking muscle twitch, in this case cardiac. Organic diseases contribute to structural changes in the anatomy of the heart and cause a violation of the conductivity of electrical impulses. This is due to an increase in the amount of connective tissue and subsequent fibrosis. This process progresses, exacerbating the dissociation of nerve fibers, therefore, fibrillation also persists.
Doctors are considering several hypotheses about how a paroxysmal form of this ailment appears. The most common are theories of foci and multiple waves. Some scientists prefer to combine both versions, since it is impossible to single out the only cause of the disease.
According to the first theory (focal), in the myocardium there are many foci of electrical activity, which are located near large vessels and along the posterior wall of the atria. Over time, they spread to the entire area of the atria. The second theory postulates that fibrillation occurs as a result of spontaneous and chaotic conduction of a large number of small waves of excitation.
Symptoms and Complications
Paroxysmal fibrillation can be asymptomatic if hemodynamic disturbances are sufficiently compensated. As a rule, patients complain of a feeling of a frequent heartbeat, pain behind the sternum 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 the attack, patients experience an increase in urination. Experts attribute this to an increase in the amount of sodium diuretic protein.
Objectively, there may be a pulse deficiency when the number of heart contractions exceeds the number of pulse waves propagating to the periphery. With an asymptomatic form of fibrillation, the first “bell” can be a stroke.
Prolonged atrial fibrillation is complicated by heart failure, thrombosis of large and small vessels of the heart or brain.
Diagnostics
Fibrillation is a random, frequent reduction in cardiomyocytes. First, the doctor collects a history of illness and life, finds out the date of the first attack, the presence of risk factors, and also learns about the medicines that the patient is taking at the moment. Patients do not complain, therefore, they discover this pathology using instrumental research methods. These include ultrasound, Holter daily monitoring and ECG. Fibrillation is manifested by the following specific signs:
- lack of a tooth of P (there is no sinus rhythm);
- the appearance of f-waves of fibrillation;
- unequal intervals between the teeth of R.
In the same way, it is possible to identify concomitant heart pathologies: myocardial infarction, arrhythmias, etc. Ultrasound investigation is performed to identify and confirm organic heart pathology, as well as measure the thickness of the myocardial walls, the volume of the atria and ventricles. In addition, parietal thrombi and vegetation on the valves are clearly visible on the screen.
In addition, after the first episode of fibrillation, the doctor prescribes an analysis for the level of thyroid hormones in order to exclude its hyperfunction.
Anticoagulant therapy
At this point, the reader already has an idea of why and how fibrillation appears. Her treatment is aimed at eliminating either the etiological factor or the leveling of the symptoms of the disease.
Anticoagulants, that is, blood thinners, are prescribed for the prevention 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 developing 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 INR (international normalized ratio). This will allow you to cancel the drug on time and reduce the risk of bleeding.
Rhythm control
Cardiac fibrillation in most cases is a reversible condition. If little time has passed since the onset of the attack, the doctor can restore the normal sinus rhythm. This can be done using a directed discharge of electric current or antiarrhythmic drugs.
Initially, the heart rate is reduced or raised to a hundred beats per minute. Then you need to take into account the risk of thromboembolism, therefore, within three weeks before the procedure and a month after it, the patient receives anticoagulant therapy. But all this is necessary only if the attack of fibrillation lasts more than two days or if the duration cannot be established. If it is known that forty-eight hours have not elapsed since the onset of chaotic heart contractions or the patient has severe hemodynamic disturbances, then rhythm restoration is carried out urgently, low molecular weight heparin is administered .
- Electric cardioversion. This is a rather painful procedure, requiring the patient to be immersed in medical sleep. In modern defibrillators, the discharge is synchronized with the R wave on the cardiogram. This avoids accidental ventricular fibrillation. As a rule, they begin with a hundred Joules and, if necessary, increase each subsequent rank by fifty Joules. This is a two phase model. A single-phase discharge is immediately done by two hundred Joules, with a maximum level of four hundred.
- Medicinal cardioversion. Preparations that can affect the heart rhythm include Procainamide, Amiodarone, Nibentan, and Propafenone.
To prevent repeated attacks of atrial fibrillation after cardioversion, antiarrhythmic drugs are prescribed, which the patient needs to take for months, or even years.
Heart rate control
All known forms of atrial fibrillation involve impaired heart rate. Therefore, doctors thought up therapy to eliminate this symptom. For this, drugs are used that can reduce the heart rate. These include:
- beta blockers;
- calcium channel blockers.
If drugs from these groups are ineffective, Amiodarone or Dronedaron are prescribed. Such therapy can reduce the manifestations of arrhythmia, but it is not at all able to remove it at all.
If treatment is ineffective, doctors sometimes resort to catheter ablation. In order to maintain sinus rhythm, it is necessary to eliminate all the excited areas. Using a radio frequency probe, the cardiac surgeon isolates the trigger areas from each other, interfering with the propagation of electric 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. Then this patient is implanted with an artificial pacemaker, which controls the number of heart contractions. The quality of life of such a patient improves markedly, but this does not affect the duration of his life.
Fibrillation after heart surgery
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 is different from that found in ordinary 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 the volume of circulating blood, 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, treatment of postoperative complications begins with the correction of all the above problems. Beta blockers, Amiodarone, steroid hormones and non-steroidal anti-inflammatory drugs are used for this.
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 healthy lifestyle, follow a diet, and prevent the increase in blood pressure above one hundred and forty. These simple actions will not only prevent the onset of fibrillation, but also help to avoid other heart diseases.
Of course, it is recommended to quit smoking and reduce alcohol consumption. In order to strengthen the vessels, cardiologists are asked to receive a sufficient amount of essential fatty acids with food or to take capsules with fish oil.
It is better to complete the treatment of bacterial and viral infections, even if subjectively you already feel good.
The risk of stroke in people with atrial fibrillation increases by fifty years to five percent, and by eighty to twenty. Every sixth registered stroke on the planet is observed in patients with a diagnosis of atrial fibrillation.