Brugada syndrome - a disease with genetic, whose peculiar changes in the electrocardiogram, as well as increased risk of SCD (sudden cardiac death).Brugada syndrome was first discovered in 1992 by two brothers, cardiologists in Spain, however, is currently practicing clinicians do not know almost nothing about this syndrome.But, nevertheless, the number of people with Brugada syndrome in the countries of the south and east Asia began to increase sharply and today this number is five patients out of 10 000 people, but in western countries this ratio varies on average two people per 10 000. Furthermore, this condition is more common among men from thirty to forty years, mainly affecting males almost nine times.
Brugada syndrome is today considered the clinical and electrocardiographic syndrome, which is characterized by the state of syncopal properties and occasional manifestations of sudden death in those patients who do not have organic heart disease and appear on the ECG BP
Clinically, the disease is divided into syncope option, which has symptoms and bessinkopalny option, which is not characteristic for symptomatic manifestations.And on the ECG it is expressed in a classical or explicitly, intermittent and latent (hidden) forms.
Brugada syndrome causes
Brugada syndrome is characterized by autosomal inheritance and dominant way.Today it is a genetic basis to mutations of several genes that are responsible for the formation of this anomaly, however mutations occurring in these genes may cause the development of this syndrome.However, in many patients the occurrence of this disease is not genetic confirmation.
Typically, Brugada syndrome is caused by abnormalities in the electrophysiological activity of the ventricle right heart at its output.The mutated gene is located on chromosome third shoulder takes part in the structure of the protein encoding sodium channel Na providing a potential current action.Basically, there are more than eighty mutations SCN 5A, which are characteristic of almost 25% of patients and more are celebrated at family options.Undoubtedly, causes the formation of this disease is the pathological changes in other genes which are responsible for encoding proteins and channels.
also suggest that not only genetic disorders play a role in the development of Brugada syndrome, and autonomic nervous system.Some studies suggest that the activation of the parasympathetic nervous system or its amplified braking arrhythmogenesis.That is why this pathology as syncopal episodes nearly 94% of cases occur either in the evening or at night.
Brugada syndrome signs
The main features symptomatic Brugada syndrome are syncopal state the nature and characteristics of sudden death.Almost 80% of patients who underwent SCD (sudden cardiac death), had a history of syncopal episodes properties.In severe cases, there fainting accession seizures.Sometimes specific attacks can occur without tripping mind, but with the advent of sudden weakness, pallor and interruptions in the work of the heart, or only a heartbeat.
But mostly clinical signs of Brugada syndrome characterized by the development of ventricular tachycardia, as well as atrial fibrillation (VT and VF).In addition, they appear mostly in the form of supraventricular tachyarrhythmias, usually atrial fibrillation.
periodic signs of ventricular arrhythmias are more common in men aged up to 38 years, but there are descriptions of cases in children and the elderly.
Brugada syndrome usually occurs during sleep or rest, with reduced heart rate, but about 15% of the pathological process is necessary after the occurrence of exercise.In addition, attacks HA (ventricular fibrillation) occur more on the background of reception of alcohol or due to fever.
There is a certain dependence of the formation of ventricular fibrillation time and the daily activity of the patients.For example, nearly 93% of VF appeared in the night, about 7% - falls on the day, but during sleep the patient - up to 87% in the period of wakefulness - 13%.
Thus, the main signs of Brugada syndrome are: VF episodes;polymorphic ventricular tachycardia character;existing cases of BCC in the history of the family up to 45 years;the presence of the first type of the disease among family members;state property or syncopal episodes during the night with sudden respiratory failure.
Brugada syndrome ECG
Electrocardiographic examination today is the most basic and effective diagnostic method.With its help it is possible to identify the signs BPNPG, which may be submitted incomplete and ST-segment elevation in leads in the presence of certain characteristic symptoms of the pathological process, which ultimately confirms the diagnosis of Brugada syndrome.Here, perhaps, is sometimes observed T-wave inversion.In addition, in order to survey using Holter monitoring can detect the presence of the changes permanent or periodical nature on an electrocardiogram before they start and after seven episodic arrhythmias.
Brugada syndrome is characterized by two types of lifts on the ECG ST-Segment in the form of "set" and "saddle".There is some connection between this segment and emerging ventricular arrhythmias.
For example, patients with type lifting ST-segment "set" predominant symptomatic forms of pathological anomalies that have a history indicate ventricular fibrillation or syncopal attacks character.In addition, these patients are often diagnosed with sudden death occurred, as opposed to those with a predominance of ECG lift-ST-segment characterized by the type of "saddle" with asymptomatic option.However, such characteristic transient changes in the electrocardiogram of standard type cause some difficulties in diagnosing this disease, so we have to look for reliable methods for confirmation of Brugada syndrome.
times to confirm the diagnosis offered the use of high right chest leads, which are recorded on the first or second intervals between the edges defined by a little higher than the standard study.In addition, when examining patients who are resuscitated after BCC with an unclear cause, as well as their relatives, have been reported signs of a pathological condition in ECG standard survey almost 70% of patients and 3% - among relatives.And when using an additional lead character, these figures are significantly increased under 92% and 10%.
Quite promising direction is also considered in the diagnosis of diseases such as recording of ECG when administered antiarrhythmic action of drugs such as flecainide and Procainamide Ajmaline.In addition, an important aspect of the survey is considered to be a special training of medical personnel to the ability to conduct the necessary resuscitation in the event of possible development of paroxysmal TJ and VF, as in the process of diagnosing the formation of such a sharply.But sometimes marked normalization of ST-Segment at the time of appointment of patients with Brugada syndrome drugs antiarrhythmic action relating to the first (A) class.
There are also descriptions of the manifestations of latent disease after taking the same drugs, but only the first (C) after failure of first-class (A) class.In order to discover the hidden Brugada syndrome and a drug used as dimenhydrinate, and pay special attention to fever.When using the M-cholinomimetics, beta-blockers and alpha-agonists are often characteristic segment elevation increases in patients with this anomaly.
After analysis on heart rate variability, according to some experts obtained data contradict each other: in some cases, increased sympathetic activity after the episodic process VF and reduced vagal tone, and in other cases the tone of the parasympathetic nervous system.Therefore, it is possible ECG reveals later ventricles.
But the diagnosis of patients with Brugada syndrome, with the addition of physical activity is sometimes normal-ST-segment elevation, and it appears in the recovery period.In addition, reveal the hidden form of the disease is quite difficult, since the methods of genetic diagnostics for today little used in clinical practice, as well as mutations occurring in the genes found not at once and not all patients with Brugada syndrome.
also important to remember that in this syndrome show no abnormalities using echocardiography, coronary angiography, endomyocardial biopsy and neurological research.
Brugada syndrome treatment
currently clear medical treatment of Brugada syndrome has not been found, and all this is due to lack of those drugs, which would be universally recognized and significantly reduced mortality of these patients.
Basically there is evidence of drugs such as disopyramide and propranolol, which effectively prevent cardiac arrhythmias, although there are cases of pronounced lifting-ST-segment in their application.Also, after intravenous administration of Isoproterenol noted the termination of ventricular fibrillation recurrence.In addition, co-administration of amiodarone, according to the authors, who described the syndrome in combination with beta blockers still does not prevent SCD.
Today modern medicine is looking for other medical devices, which would be effective in the treatment of Brugada syndrome.For example, in clinical practice, cilostazol technique (described in a single case) could prevent regular episodes of VF, which confirmed the test with a periodic cancellation.But to reduce the segment elevation characteristic influence blockers, agonists and catecholamines.
But nevertheless, now the only effective treatment for patients with symptomatic variant Brugada syndrome is considered conduct surgery with implantation of a cardioverter-defibrillator, which prevents episodes of sudden death.Administration of amiodarone in the presence of this unit reduces the frequency of its discharges.The indications for implantation for patients with asymptomatic Brugada syndrome are: representatives of the male between the ages of thirty to forty years;those patients who have a family history of sudden death;confirmed by spontaneous gene mutation and ECG changes.
Thus, Brugada syndrome mainly characterized by poor prognosis as death occurs as a result of VF with a frequency ARIA ten to forty percent.In addition, the risk of death is the same as for permanent and periodic changes in the ECG.