Brugada syndrome is a genetically determined disease where there is a tendency to the occurrence of life-threatening ventricular arrhythmias. The first description of the disease dates back to 1992, and the authors of the publication were Spanish cardiologists - brothers Joseph and Pedro Brugada.

Brugada syndromeis relatively rare. Its occurrence is estimated at an average of 1-30 per 100,000 people, with the highest number of cases among the inhabitants of Asia. Men get sick 8-10 times more often than women.

Brugada syndrome: causes

Due to the pathophysiology of the syndrome, it belongs to the group of arrhythmogenic heart diseases called channelopathies. The cause of the Brugada syndrome is a mutation in the gene encoding the protein subunit of the sodium channel.

Sodium channels are located in the cell membranes of the heart muscle cells and take part in their depolarization, i.e. stimulation, the final effect of which is the contraction of muscle fibers. The abnormality of the sodium channel shortens the time of depolarization of individual fibers, which disturbs the even and synchronized propagation of the excitation wave.

The effect is changes in the ECG recording, and most importantly, dangerous ventricular arrhythmias. The syndrome is inherited in an autosomal dominant fashion.

Currently, several dozen types of mutations responsible for the disease are known. However, genetic testing is not routinely performed for diagnostic purposes.

Brugada syndrome: symptoms

Brugada syndrome most often appears in young adults - in the 3rd and 4th decade of life. The main clinical symptom is syncope due to polymorphic ventricular tachycardia.

Arrhythmia often occurs at rest, usually at night. The most dangerous effect of the disease is sudden cardiac death as a result of the transformation of the above-mentioned tachycardia into ventricular fibrillation.

Unfortunately, it is possible that a cardiac arrest in VF may be the first manifestation of the disease.

Brugada syndrome: diagnosis

The essential element of the diagnosis is the characteristic ECG trace, i.e. the electrocardiogram. The Brugada syndrome is characterized by characteristic changes in the morphology of the QRS complexes and the ST-T area.

These features appear in leads V1 and V2, that islocated above the right ventricle. Occasionally, the typical syndrome recording is a random find during an ECG for other reasons.

The patient has a chance to be taken under specialist care before symptoms become apparent. It is worth mentioning that the ECG image can be very variable - it will spontaneously fade and reappear.

There are 3 types of ECG changes in Brugada syndrome. The 2,3 types are less severe, so the diagnosis may be questionable. For this purpose, provocation tests with antiarrhythmic drugs are used for diagnostics, which can convert them to type 1 and thus confirm the diagnosis.

Brugada syndrome: treatment

As with most genetically determined diseases, treatment of Brugada syndrome is largely limited and comes down to the prevention of sudden cardiac death.

The main element is recommendations for lifestyle modification and limiting factors that may induce arrhythmias, such as alcohol consumption or heavy meals.

It is important to be aware of drugs with high arrhythmogenic potential, which should be avoided by those affected by the syndrome. Their list can be found on the dedicated website www.brugadadrugs.org

Arrhythmia can also be triggered by electrolyte disturbances and fever. For this reason, it is recommended to aggressively lower it in the case of, for example, infectious diseases.

In a patient with Brugada syndrome, consider implanting a cardioverter-defibrillator (ICD) - a device that detects and terminates life-threatening arrhythmias using appropriate electrical discharges.

  • Cardioverter-defibrillator (ICD) - what is it? How does it work?

The ICD implantation procedure is indicated primarily in patients who have experienced cardiac arrest and with fainting as a result of documented ventricular tachycardia. It is not recommended for asymptomatic patients.

Pharmacological treatment is of limited importance and does not allow for complete and effective treatment of tachycardia attacks and sudden cardiac death. Quinidine has the most effective action. It can be used, among others in patients with contraindications to ICD implantation and in the case of recurrent device interventions.

Ablation over the anterior wall of the RV outflow tract can also be used as an alternative treatment.

Brugada syndrome: prognosis

The prognosis for Brugada syndrome varies according to the presence of symptoms. Patients with a history of arrhythmic syncope ispontaneous ECG changes have a higher risk of potentially fatal arrhythmic events than people without clinical history.

Sources:

  1. "Cardiac arrhythmias in everyday medical practice" edited by K. Mizi-Stec and M. Trusz-Gluzy, ed. MedicalTribunePolska 2015
  2. "Interna Szczeklika 2022/18" published by Medicin practical

Category:

Cardiology