Brugada Syndrome

The Brugada Syndrome

• Genetic condition associated with arrhythmia (polymorphic VT) and sudden cardiac death that was originally described in adolescent males in southeast Asia

• Described in 1992 by Pedro and Josep Brugada

  • Initially described in 1988 by Nava, with the first complete description in 1989 by Martini, Nava, et al. (PMID: 2589161)

• Individuals thought to be usually healthy with structurally normal hearts

  • Primarily an electrical problem (sodium channelopathy)

  • Increasing literature demonstrates that there may actually be structural abnormalities that are technically difficult to diagnose

• First onset of symptoms (VT, VF, syncope, sudden death)

  • 41 ± 15 years on average for VF episodes

  • Arrhythmias reported from 2-84 years

  • A reported cause of SIDS or sudden cardiac death in young children

  • Positive family history in 20-30%

• More common than you may realize!

  • 4% of ALL sudden deaths

  • 20% of sudden death in patients with structurally normal hearts

  • A leading cause of death in patients < 40 years of age

  • Prevalence in general population ~1/2000

  • Identified in all ethnic groups, both males and females

• Mortality

  • Early data: ~ 10% per year if not treated with internal cardioverter-defibrillator (ICD, only effective treatment)

  • New data showing VF episodes and mortality rates are probably lower, mainly with Type I (coved) pattern

  • Isoproterenol and quinidine may decrease incidence

    • Quinidine not shown to improve outcomes and is not easily available

    • Isoproterenol may be helpful in arrhythmic storm

• Arrhythmic events happen at rest or sleep esp. 12am-6am (during increased vagal tone)

• Fever and hot ambient temperature bring out the ECG findings and PVT/VF episodes

  • Treat fevers aggressively

• Type Ia and Ic medications increase the ECG findings (questionable if increases arrhythmias)

The Brugada Syndrome: Diagnosis

• Diagnosis requires 2 parts (ECG findings + clinical findings)

1. Typical ECG abnormalities reviewed above (esp. coved type)

2. Clinical characteristics, 1 of the following:

• • • History of VT/VF

    • FHx of sudden cardiac death

    • FHx of coved-type ECG

    • Agonal respirations during sleep

    • Inducible VT/VF or the coved ECG finding during EP study

References

1. Vohra J, Rajagopalan S, CSANZ Genetics Council Writing Group. Update on the Diagnosis and Management of Brugada Syndrome. Heart Lung Circ 2015;24(12):1141–8. PMID: 26412486

2. Martini B, Nava A, Thiene G, et al. Ventricular fibrillation without apparent heart disease: description of six cases. Am Heart J. 1989 Dec;118(6):1203-9. PMID: 2589161

3. Viskin S, Hochstadt A, Rosso R. Type-I Paradox of Brugada Syndrome. Journal of the American Heart Association 2018;7(10). PMID: 29748179

4. Pieroni M, Notarstefano P, Bolognese L. Brugada Syndrome in the Young and in the Adult: A Tale of 2 Diseases? J Am Coll Cardiol 2019;73(14):1766–8. PMID: 30975292

5. Ueoka A, Morita H, Watanabe A, et al. Prognostic Significance of the Sodium Channel Blocker Test in Patients with Brugada Syndrome. Journal of the American Heart Association 2018;7(10). PMID: 29748178

6. Papadakis M, Papatheodorou E, Mellor G, et al. The Diagnostic Yield of Brugada Syndrome After Sudden Death With Normal Autopsy. J Am Coll Cardiol 2018;71(11):1204–14. PMID: 29544603

7. Delise P, Allocca G, Sitta N, et al. Cardiac arrest and Brugada syndrome: Is drug-induced type 1 ECG pattern always a marker of low risk? International Journal of Cardiology 2018;254:142–5. PMID: 29180267