Brugada Syndrome - Causes, Symptoms and Treatment .MF .
The normal heart beats at a frequency of 60 - 80 beats per minute.Deviations from the norm may indicate bradycardia (below normal) or tachycardia (above normal).Tachycardia is developing as a response to stress, physical stress or illness.In addition, rapid heart rhythms may result from organic heart disease, such as inflammation of the heart muscle cells or their death (myocardial infarction or myocarditis).Such tachycardia, especially if they develop from ventricular tissue, rather than the atria, are very dangerous for human health, since in some cases, can cause cardiac arrest.
In recent years, scientists have found that ventricular tachycardia occurs not only with the defeat of the heart tissue inflammation, necrosis (death) or its replacement with scar tissue, but also in the case of a complete lack of apparent reason in the presence of a healthy heart in a patient.However, invisible to the naked eye, the cause is still there.It - Brugada syndrome, which is caused by more than 50% of all cases of
So, Brugada syndrome - is genetically determined metabolic disturbance of trace elements in the cardiac muscle cells (myocytes), leading to a sudden unprovoked paroxysm of ventricular tachycardia with loss of consciousness or not, with a high risk of sudden cardiac death.This syndrome refers to the list of reasons that cause paroxysmal ventricular tachycardia.
What happens with Brugada syndrome?As you know, all the information about the human body is encoded in genes, which are the "building blocks" of the chromosomes.This information includes several parameters from the eye to the color formation of proteins in the cells responsible for the functioning of internal organs.Activity of myocytes also is influenced by genes as they are synthesized proteins, carrying sodium, potassium and calcium into the cell and out.In turn, these substances play an important role in the electrochemical processes that reduce and relax the cells.That is, the frequency of contractions of muscle cells of the heart depends on the influx of sodium ions into the cell.When this syndrome observed genetic mutation resulting in the inactivation of sodium channels in myocytes, and there is an abnormal electrical activity of the myocardium.More prone to the right ventricle, which is most often formed focus of excitation, causing a paroxysm of tachycardia.
Brugada syndrome is most common in Southeast - Asia (1 - 60 persons per 10 thousand people, according to different authors), the prevalence among Europeans less.Most men suffer than women.There are syncope (with loss of consciousness) and bessinkopalny (asymptomatic) syndrome types.
Brugada syndrome Causes
cause is mutation of genes responsible for the synthesis of proteins transporting sodium ions into the cell.The disease is inherited in an autosomal - dominant manner, that is, if the mutated gene will be transferred to a child or from the mother or father, it must manifest itself in the form of the disease, in contrast to the recessive mode of inheritance, when they should meet two mutated genes, one from each parent,disease to manifest in the child.Brugada syndrome can occur in the offspring in the ratio of 1: 1, that is, half of all children born in a marriage where one parent is a carrier of the mutated gene and will suffer from this disease.
Risk factors for the presence of Brugada syndrome include:
- the presence of syncope in patients without an established cause
- family history of sudden cardiac death (especially if there have been cases of death of men in the family aged 30 - 40 years without apparent heart disease)
- patient cases were paroxysmal ventricular tachycardia.
symptoms of Brugada syndrome
Despite the fact that the syndrome is a genetic, ie a congenital disease, it appears most often between the ages of 30 - 40 years.However, the described isolated cases of sudden death caused by the Brugada syndrome in children and adolescents.
main manifestation of a syndrome - a paroxysm of ventricular tachycardia, in most cases accompanied by loss of consciousness (syncope).The patient is at rest (in the evening or at night), as well as after exercise, alcohol use, or during fever, feeling a sudden malaise, tremors in the heart, followed by a distinctly perceptible heartbeat.All this may be accompanied by stunning, sweating, dizziness, flies flashing before his eyes.The patient may lose consciousness, sometimes accompanied by convulsions.After 20 - 30 seconds of consciousness is completely restored, but in 11% of cases may develop ventricular fibrillation and cardiac arrest.
Sometimes the syndrome is manifested tachycardia paroxysm without loss of consciousness.
Brugada syndrome diagnosis
To diagnose but examination of the patient, apply:
1. ECG.Signs on the ECG:
- complete or incomplete blockade of the right bundle branch
- elevation (rise) of the point j (transition point of the QRS complex in the ST segment represents ventricular depolarization).
- ST segment elevation on the "arch" type or "saddle".According arch type corresponds to the form of syncope syndrome, according to the type of seat - bessinkopalnoy.
These symptoms are recorded in the right precordial leads (V1 - V3).ECG - signs of the syndrome can be detected after a 5 - year age groups.
The figure shows the signs of the syndrome in an "arch" (Type 1) and "saddle" (types 2 and 3).
2. ECG high chest leads are appointed in the presence of transient changes in the normal ECG.To record high chest leads electrodes are superimposed on one - two intercostal spaces higher than usual.
3. ECG monitoring is indicated for the detection of short runs of ventricular arrhythmias during the night and during the day.
4. Electrophysiological study (transesophageal or invasive) is assigned for the purpose of more accurate recording of ECG after electrical stimulation of the heart.
5. Test with the introduction of the sodium channel blockers (aymalin, procainamide) is applied only in a hospital or intensive care unit, and is administered by intravenous drugs with registration ECG.A positive test is considered in the development of paroxysmal ventricular tachycardia and / or signs of Brugada syndrome.
6. Genetic studies are appointed in order to find the mutated gene for the confirmation of the disease or the patient's relatives survey already installed syndrome, especially when it comes to planning for children patients.However, the accuracy of the method is only 20 - 30%, so a negative result of the analysis does not allow to reject the diagnosis of the syndrome.
7. Consultation of the neurologist, neurosonography, MRI of the brain.Showing neurogenic nature to avoid fainting.
Treatment of Brugada syndrome
At the moment, drug treatment, which allows to eliminate the disease completely, does not exist.Studies are under way, aimed at to learn how to fix genetic defects that caused the syndrome.Medications used for the prevention and paroxysmal ventricular arrhythmias to reduce the risk of sudden cardiac death.
Used Class 1A antiarrhythmic drugs -hinidin, disopyramide (ritmodan).It can be assigned to amiodarone (Cordarone).Antiarrhythmics other classes are contraindicated because they can induce ventricular fibrillation.This is especially true procainamide, aymalina, propafenone, and other drugs that block sodium channels.From the beta - blocker propranolol is appointed.
Surgical treatment is the most effective in the treatment of the syndrome and is installing cardioverter - defibrillator.This type of artificial pacemaker function is reduced to two nuances - determination of heart rate and the development of ventricular arrhythmias by cardiac defibrillation electrodes located intracardiac.Defibrillation help restart the heart, restoring the correct timing contractions.
Lifestyle with Brugada syndrome
any preventive measures that can prevent the development of attack, has not been developed.However, compliance with the principles of a balanced diet, limiting extreme sports, with the exception of stress has beneficial effects on the cardiovascular system as a whole.
Patients with an established diagnosis of life should occur in arrhythmology, take prescribed medication and time to be screened.With an installed cardioverter - defibrillator cardiac surgeon must attend each year, and the replacement of a pacemaker should be carried out according to the date of his work, usually within 4 - 6 years, depending on the model.
couples in which one spouse is sick, when planning a child, be sure to visit the medical and genetic counseling and undergo an examination to assess the risk of having a child with Brugada syndrome, as well as to determine the tactics of pregnancy and childbirth.
Complications Complications are
Brugada syndrome, life-threatening condition - fatal arrhythmias (sustained ventricular tachycardia, ventricular fibrillation in passing), asystole and clinical death.
Prognosis is poor, since according to the authors, first described this syndrome, 30% of patients die within the first three years from the onset of clinical manifestations.Follow-up studies of a larger group of patients showed that the index remains within the 11%, but nevertheless still mortality is high, especially when you consider that the syndrome manifests in young adults.
therapists Sazykina OJ