The Brugada syndrome is a genetic disease that is manifest by abnormal electrocardiogram (ECG) findings and an increased risk of sudden cardiac death. It is also known as Sudden Unexpected Death Syndrome¹ (SUDS), and is the most common cause of death in the young in Thailand and Laos².

First described in 1992³, the Brugada syndrome causes sudden death by causing ventricular fibrillation (a lethal arrhythmia) in the heart.

Genetics and pathophysiology

Brugada syndrome is due to a mutation in the gene that encodes for the sodium ion channel in the cell membranes of the muscle cells of the heart (the myocytes). The gene, named SCN5A, is located on the short arm of the third chromosome (3p21).

Electrocardiography

In some cases, the disease can be detected by observing characteristic patterns on an electrocardiograph, which may be present all the time, or might be elicited by strenuous exercise, or by the administration of particular drugs. The pattern seen on the ECG is persistent ST elevations in V₁-V₃ with a right bundle branch block (RBBB) appearance without the terminal S waves in the lateral leads that are associated with a typical RBBB.

Treatment

The cause of death in Brugada syndrome is ventricular fibrillation. Whlie there is no treatment modality that prevents ventricular fibrillation from occurring in this syndrome, treatment lies in termination of this lethal arrhythmia before it causes death. This is done via implantation of an implantable cardioverter-defibrillator (ICD), which continuously monitors the heart rhythm and will cardiovert an individual if ventricular fibrillation is noted.

External links

• Graham-Rowe: "Death in the Family", New Scientist 20 Sept. 2002
• Algado et al: http://www.medspain.com/ant/n13_jun00/Brugada.htm
• Winstead: http://www.celera.com/genomics/news/articles/01_01/fatal_flaw.cfm
• Behr: http://www.c-r-y.org.uk/long_qt_syndrome.htm
• http://molecularmedicine.medscape.com/reuters/prof/2000/09/09.01/20000901scie006.html
• OMIM 600163

Related topics

• Cardiac action potential
• Genetics
• Ion channel

References

1. Hong K, Berruezo-Sanchez A, Poungvarin N, Oliva A, Vatta M, Brugada J, Brugada P, Towbin JA, Dumaine R, Pinero-Galvez C, Antzelevitch C, Brugada R. Phenotypic characterization of a large European family with Brugada syndrome displaying a sudden unexpected death syndrome mutation in SCN5A. J Cardiovasc Electrophysiol. 2004 Jan;15(1):64-9. (Medline abstract)

2. Brugada J, Brugada P, Brugada R. The syndrome of right bundle branch block ST segment elevation in V1 to V3 and sudden death--the Brugada syndrome. Europace. 1999 Jul;1(3):156-66. (Medline abstract)

3. Brugada P, Brugada J. Right bundle branch block, persistent ST segment elevation and sudden cardiac death: a distinct clinical and electrocardiographic syndrome. A multicenter report. J Am Coll Cardiol. 1992 Nov 15;20(6):1391-6. (Medline abstract)