Syndrome Brugada

Brugada syndrome is a disease with a genetic character, which is characterized by changes in the electrocardiogram, as well as increased risk of BCC( sudden cardiac death).For the first time, Brugada's syndrome was discovered in 1992 by two brothers, cardiologists from Spain, but at the moment practicing clinicians practically know nothing about this syndrome. But, nevertheless, the number of people with Brugada syndrome in countries in the south and east of Asia began to increase sharply and to date this number is five patients out of 10 000 people, but in Western countries this ratio varies on average two people per 10 000In addition, this condition is more common among people from thirty to forty years with a predominantly male lesion almost nine times.

Syndrome Brugada is now considered a clinical and electrocardiographic syndrome, which is characterized by a syncopal condition and episodic manifestations of sudden death in those patients who do not have organic cardiac pathologies and which manifest themselves on the ECG of the BPHP( right bundle bundle blockage) of a permanent or transient nature andThe ST-segment ascends in the thoracic leads to the right.

Clinically, the disease is divided into a syncopal variant, which has symptoms and a non-syncopal variant, for which symptomatic manifestations are not characteristic. And on the ECG, it is expressed in classical or explicit form, intermittent and latent( latent) forms.

Syndrome Brugada causes

Brugada syndrome is characterized by inheritance on the autosomal and dominant pathway. To date, its genetic basis is the mutation of several genes that are responsible for the formation of this anomaly, so the mutations occurring in these genes can cause the development of this syndrome. However, in many patients the occurrence of this pathology has no genetic confirmation.

As a rule, Brugada's syndrome develops as a result of anomalies in the electrophysiological activity of the ventricle of the right heart at its exit. A mutated gene located on the arm of the third chromosome, takes part in the coding of the structure of the protein of sodium channels, providing potential Na action current. In general, there are more than eighty mutations in the gene SCN 5A, which are characterized by almost 25% of patients and a greater number is noted in family variants. Undoubtedly, the causes of the formation of this disease are pathological changes in other genes that are responsible for the encoding of proteins and channels.

It is also suggested that not only genetic disorders play a role in the development of Brugada's syndrome, but also an autonomic nervous system. Some studies show that the activation of the parasympathetic nervous system or its inhibition increases arrhythmogenesis. That is why this pathology in the form of syncopal attacks almost in 94% of cases occurs either in the evening or at night.

Syndrome Brugada signs

The main symptomatic signs of the Brugad syndrome include states of syncopal nature and signs of sudden death. Practically in 80% of patients who suffered BCC( sudden cardiac death), there was a history of syncope attacks. And in severe cases, fainting with adherence to seizures is observed. Sometimes characteristic seizures can occur without turning off consciousness, but with the appearance of sudden weakness, pallor and irregularities in the activity of the heart or just heartbeats.

But mostly the clinical signs of the Brugada syndrome are characterized by the development of ventricular tachycardia, as well as their fibrillation( VT and VF).In addition, they are manifested, mainly, in the form of supraventricular tachyarrhythmias, usually by atrial fibrillation.

Periodic signs of ventricular arrhythmias are more common in men under 38 years of age, but there are descriptions of cases in children and the elderly.

Brugada syndrome usually appears during sleep or rest, with a reduced heart rate, but about 15% of the pathological process occurs after physical exertion. In addition, GI attacks( ventricular arrhythmia) still occur against the background of alcohol intake or as a result of a febrile condition.

There is a definite dependence of the formation of ventricular fibrillation on the daily time and activity of patients. For example, almost 93% of VF appeared at night, about 7% - per day, while in the sleep period of the patient - up to 87% and in the waking period - 13%.

Thus, the main signs of the syndrome of Brugada are: episodes of VF;Ventricular tachycardia of polymorphic nature;Available cases of SCD in a family history up to 45 years;Presence of the first type of disease among family members;Condition syncopal properties or attacks at night with a sharp violation of breathing.

ECG Syndrome

Electrocardiography is currently the most basic and effective diagnostic method. With its help, it is possible to identify signs of BPHP, which can be represented incomplete and ST-segment elevation in certain leads in the presence of a characteristic symptomatology of the pathological process, which ultimately confirms the diagnosis of Brugada syndrome. Here, perhaps, sometimes observe the inversion of the T-wave. In addition, using the Holter monitoring for monitoring purposes, it is possible to record the changes of a permanent or recurrent nature on the ECG, before and after, seven episodic arrhythmias.

Brugada syndrome is characterized by two types of ascents on the ST-segment ECG in the form of a "vault" and "saddle".There is a definite relationship between this segment and the resulting disturbances in the rhythm of the ventricles.

So, for example, in patients with the type of ST-segment elevation of the "arch", symptomatic forms of a pathological anomaly predominate, which in history have indications of ventricular fibrillation or attacks of a syncopal nature. In addition, in these patients, sudden death is often diagnosed, in contrast to persons with an ECG elevation of the ST segment, characterized by the "saddle" type with an asymptomatic variant. However, such characteristic transient changes on the standard electrocardiogram cause some difficulties in diagnosing this disease, so we have to look for reliable methods of confirming the Brugada syndrome.

Sometimes, to confirm the diagnosis, the use of high right thoracic leads is suggested, which are recorded at the first or second intervals between the ribs, determined somewhat higher than in the standard study. In addition, when examining patients who were resuscitated after SCD with an unclear cause of their occurrence, as well as their relatives, signs of a pathological condition on the ECG of a standard examination were registered in almost 70% of patients and 3% among relatives. And when using additional leads, these indicators increase significantly in accordance with 92% and 10%.

The direction in diagnostics of the given disease as registration of parameters on an electrocardiogram at introduction of preparations of antiarrhythmic action, such as Flekainid, Prokainamide and Aymalin is enough perspective also. In addition, an important aspect of such a survey is the special training of medical personnel in the ability to carry out the necessary resuscitative measures in the event of the possible development of paroxysmal TJ and FF, since in the process of such diagnosis, these formations sharply increase. But sometimes there is a normalization of the ST-segment at the time of the appointment of antiarrhythmic drugs belonging to the first( A) class to patients with the Brugada syndrome.

There are also descriptions of the manifestations of the latent form of pathology after taking the same drugs, but only the first( C) class when the first( A) class is ineffective. In order to detect the hidden syndrome of Brugada, a drug such as Dimenhydrinate is also used, and special attention is paid to the febrile state. When M-cholinomimetics, beta-adrenoblockers and alpha-adrenomimetics are used, the elevation of a characteristic segment in patients with such an anomaly is very often increased.

After the analysis of heart rate variability, according to some experts, data contradicting one another is obtained: in some cases sympathetic activity after episodic VF process increases and vagal tone decreases, and in other cases the tone of the parasympathetic nervous system increases. Therefore, it is the ECG that detects the late capacity of the ventricles.

But when diagnosing patients with the Brugada syndrome with the addition of physical exertion, the ST segment is sometimes normalized and its elevation appears during the recovery period. In addition, it is rather difficult to identify hidden forms of the disease, since the methods of genetic diagnostics are not widely used in clinical practice today, and mutations occurring in genes are detected not immediately and not in all patients suffering from Brugada syndrome.

It is also important to remember that this syndrome does not show pathologies using Echocardiography, coronary anti- angiography, endomyocardial biopsy, and neurological examinations.

Syndrome Brugada treatment

To date, no clear drug treatment for Brugada syndrome has been found, and all this is due to the lack of those drugs that are generally recognized and reliably reduced the mortality of these patients.

Basically, there are confirmations of such drugs as Dizopyramid and Propranolol, which effectively prevent cardiac arrhythmias, although there are cases of pronounced ST-segment elevation when they are used. Also, after intravenous administration of Isoproterenol, abnormalities of recurrence of ventricular fibrillation were noted. In addition, the simultaneous administration of Amiodarone, according to the authors who described the syndrome, in combination with beta-blockers still does not warn ARIA.

Today, modern medicine is looking for other medical products that would be effective in treating the Brugada syndrome. For example, in clinical practice, taking Cilostazol( described as a single case) was able to prevent regular episodes of VF, which was confirmed by a test with periodic cancellation. But the decrease in the elevation of the characteristic segment is affected by adrenoblockers, adrenomimetics and catecholamines.

But, nevertheless, an effective and the only method of treatment for patients with a symptomatic variant of Brugada syndrome is considered to be an operative intervention with the implantation of a cardioverter-defibrillator that prevents episodes of sudden death. The introduction of Amiodarone in the presence of this apparatus leads to a decrease in the frequency of its discharges. Indications for implantation for patients with asymptomatic course of the Brugada syndrome are: representatives of the male at the age from thirty to forty;Those patients who have a sudden history of a family history;Confirmed gene mutation and spontaneous ECG changes.

Thus, basically Brugada syndrome is characterized by an unfavorable prognosis, since the lethal outcome comes as a result of VF with a BCC frequency of ten to forty percent. In addition, the risk of a fatal outcome is the same, with both permanent and periodic ECG changes.