Brugada syndrome

Last edited 11/2022 and last reviewed 02/2023

Brugada syndrome is a rare inherited cause of sudden cardiac death (SCD) (1,2,3)

Types of Brugada Syndrome according to the ECG appearance

• Type 1: 2mm or more coved (concave) ST elevation and negative T wave is seen in at least 2 of the leads V1, V2 or V3. This pattern may be absent at rest and may arise only after administration of a sodium channel blocking agent.
• Type 2: Saddleback ST segment elevation is seen. The J point is elevated at least 2mm and the ST segment is elevated at least 1 mm. T wave may be positive (upright) or biphasic
• Type 3: has either a saddleback or coved appearance with an ST-segment elevation of < 1 mm.
  

Mutation of the cardiac sodium channel gene SCN5A has been identified in some clinical cases, but most of the reported cases have been adult male patients despite the condition's autosomal dominant inheritance

• the autonomic nervous system is considered to play an important role in modulation of this ECG abnormality
• yield of genetic testing in Brugada syndrome patients is approximately 20%, with the SCN5A gene the only gene with evidence of association for clinical testing purposes (4)
• a study has found that subjects with the Brugada-type ECG have slender builds (2). The authors suggest that this may provide a clue to the basic mechanisms of the Brugada-type ECG with a focus on this association
• prevalence varies from 5 to 20 in every 10,000, and it is considered endemic in Southeast Asian countries (5)

Brugada syndrome is a diagnosis of exclusion: the differential diagnoses should be excluded first.

Presentation

• often asymptomatic.Typically presents 3rd - 4th decade with syncope or SCD (3)
• approximately one-third of Brugada syndrome patients present with syncope (4)
  • risk of arrhythmic events in Brugada syndrome patients with unexplained syncope is 4 times higher than the risk in asymptomatic patients

Click here for an example ECG and further information

Reference:

1. Brugada P, Brugada J.Right bundle branch block, persistent ST elevation and sudden cardiac death: a distinct clinical and electrocardiographic syndrome. A multicenter report. J Am Coll Cardiol 1992;20:1391?1396
2. Matsuo et al. Clinical Characteristics of Subjects with the Brugada-Type Electrocardiogram. Journal of Cardiovascular Electrophysiology 2004;15 (6): 653-657
3. British Heart Foundation (2009).Factfile 5/09, Inherited cardiovascular disease.
4. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death: Developed by the task force for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death of the European Society of Cardiology (ESC) Endorsed by the Association for European Paediatric and Congenital Cardiology (AEPC), European Heart Journal, 2022;, ehac262, https://doi.org/10.1093/eurheartj/ehac262
5. Brugada R, Campuzano O, Sarquella-Brugada G, Brugada J, Brugada P. Brugada syndrome. Methodist Debakey Cardiovasc J. 2014 Jan-Mar;10(1):25-8.