Brugada syndrome in children: symptoms, diagnosis, treatment

Brugada syndrome is classified as a primary electrical heart disease with a high risk of sudden arrhythmic death.

This syndrome is characterized by right ventricular conduction delay (right bundle branch block), ST segment elevation in the right precordial leads (V1-V3) on the resting ECG, and a high incidence of ventricular fibrillation and sudden death, predominantly at night.

Epidemiology

It is generally accepted that the syndrome is diagnosed with a frequency of 4 to 12% of all cases of sudden cardiac death. Brugada syndrome is 8-10 times more common in males.

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Causes of Brugada Syndrome

In 15-20% of patients with Brugada syndrome, a mutation in the sodium channel gene SCN5A has been detected. In most patients, the genetic nature of the Brugada syndrome phenotype remains unclear.

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Symptoms of Brugada Syndrome

The diagnostic criteria for Brugada syndrome are considered to be a combination of mandatory detection of covedST segment elevation (type 1 syndrome) in at least one of the right precordial leads (V1-V3) on a resting ECG or during a test with a sodium channel blocker with one of the following clinical signs:

• documented episodes of ventricular fibrillation;
• polymorphic ventricular tachycardia;
• cases of sudden death in the family at the age of up to 45 years;
• presence of the Brugada syndrome phenotype (type I) in family members;
• induction of ventricular fibrillation with a standard protocol of programmed ventricular stimulation;
• syncopal states or nocturnal attacks of severe respiratory distress.

Individuals with ECG phenomenon type 1 should be monitored as patients with idiopathic ECG pattern and not Brugada syndrome. Thus, the term "Brugada syndrome" currently refers only to the combination of type 1 with one of the above clinical and anamnestic factors.

The first symptoms of Brugada syndrome usually appear in the 4th decade of life. Sudden death and defibrillator activation in patients are mainly recorded at night, which indicates the importance of increased parasympathetic influences. However, the syndrome can also manifest in childhood. Symptoms can appear during an increase in body temperature. If a combination of spontaneous type 1 ECG Brugada phenomenon with attacks of loss of consciousness is detected in childhood, Brugada syndrome is diagnosed and implantation of a cardioverter-defibrillator with subsequent administration of quinidine is recommended.

Treatment of Brugada syndrome

Current treatment recommendations include quinidine at a dose of 300-600 mg/day or higher. Isoproterenol has also been shown to be effective in suppressing the "electrical storm" in patients with Brugada syndrome. Implantation of a cardioverter-defibrillator is the only effective method for preventing sudden death. Symptomatic patients should definitely be considered candidates for implantation. In asymptomatic patients, the following are considered indications for implantation:

• induction of ventricular fibrillation during an electrophysiological study in combination with spontaneous or registered during a test with a sodium channel blocker type 1 ECG Brugada phenomenon;
• Brugada phenomenon type 1 induced by the test in combination with the presence of cases of sudden death in young people in the family.

Persons with ECG Brugada phenomenon (type 1) induced by tests in the absence of symptoms and cases of sudden arrhythmic death in the family need observation. Electrophysiological study and implantation of a cardioverter-defibrillator are not indicated in these cases.

The optimal strategy for the prevention of sudden arrhythmic death in patients with primary electrical heart disease is the determination of baseline risk (modifiable and non-modifiable risk factors and markers) and subsequent monitoring of patients in accordance with their individual risk profile.