The Brugada syndrome (BS) is characterized by ventricular arrhythmias in the presence of characteristic ECG abnormalities and a structurally normal heart, resulting in recurrent syncope and/or sudden cardiac death. It is usually genetically inherited in an autosomal dominant manner with incomplete penetrance. The underlying genetic defects generally cause reduced sodium inflow to cardiomyocytes during phase 0 of the cardiac action potential, thus shortening the duration of the action potential.

The initial presentation may be syncope or resuscitated sudden cardiac arrest due to polymorphic ventricular tachycardia or ventricular fibrillation. Onset is generally after adolescence, peaking in the third or fourth decade of life. Arrhythmias occur most commonly at night or at rest. The diagnosis may also be made on a routine ECG or family screening.

BS is reported to be responsible for 4% of all sudden deaths and 20% of sudden deaths in those without structural heart disease. A family history is present in about 20%-30% of patients. Prevalence in the general population is estimated at approximately 0.05%. It is particularly common among patients of Southeast Asian descent.

The "Brugada pattern" ECG consists of an atypical right bundle branch block with cove-shaped ST elevation in leads V1 to V3 in the absence of obvious structural heart disease, electrolyte disturbances, or ischemia. The ECG findings may be present at baseline or may only become apparent in the setting of a fever or with use of medications having sodium channel blocking activity, such as class I antiarrhythmics, tricyclic antidepressants, alcohol, or cocaine. Intermittent presence of the characteristic ECG pattern makes the diagnosis difficult in some patients.