Brugada syndrome

Background

  • Consider as cause of syncope in patients with family history of sudden death
  • 80% of Brugada syndrome diagnosed only after a cardiac arrest[1]
  • Autosomal dominant Na-channelopathy which increases the risk of sudden cardiac death (~10%/yr)[2]
  • Much more common in men (up to 9x), particularly Southeast Asian males
  • ECG shows incomplete RBBB with ST elevation in V1-V3
    • In uncomplicated RBBB, usually there is no ST change to slight ST depression
    • If presenting symptom is chest pain rather than syncope, consider strongly STEMI

Clinical Features

  • Typically asymptomatic
  • Patients may have Vfib cardiac arrest or sudden death
  • Diagnostic ECG findings transient and variable, with only 1/3 of serial ECGs diagnostic in confirmed spontaneous coved-type Brugada syndrome patients[3]

Differential Diagnosis

ST Elevation

Evaluation

ECG Criteria

Brugada ECG findings by type.
  • Type 1
    • Elevated ST segment (>2mm)
    • Descends with upward convexity to a TWI
  • Type 2
    • Elevated ST segment (>1mm)
    • Descends toward baseline then rises again (saddleback) to upright T wave
  • Type 3
    • Elevated ST segment (<1mm)
    • Descends toward baseline then rises again to upright T wave


v1-v2 lead placement in 2nd or 3rd IC spaces (rather than conventional 4th IC space) increases chance of recording type I pattern[4]

ECG Unmasking Factors[5][6][7]

  • Type 1 ECG findings can be transient and "unmasked" by the following:
    • Fever
    • Night time
    • After heavy meals
    • Recovery phase of exercise[8]

Higher Risk ECG Features

Diagnosis

  • Diagnosed when a patient has Burdada's ECG pattern (see above) AND documented ventricular tachydysrhythia or history consistent with ventricular tachydysrythmia (e.g. syncope, sudden cardiac death)[13]

Management

Acute ED management depends on presenting symptoms

Incidental Brugada Pattern on ECG (Otherwise Asymptomatic)

  • No acute treatment

Concerning Cardiac Symptoms

  • Cardiology consultation and likely admission
    • Consider EP consult and VF-inducing electrophysiologic study (EPS), though EPS is controversial prognosticator[14]

Active Tachydysrhythmia

Drugs to be Avoided

Disposition

  • Incidental finding with no suggestive family or patient history (e.g. syncope, tachydysrhythmia, sudden cardiac death)--> education and general cardiology referral[16]
  • Suggestive family or patient history --> disposition in consultation with cardiology[17]
  • Active tachydysrhythmia --> admission[18]

Inpatient vs Outpatient ICD Placement

  • Prophylactic ICDs may have risks of complications greater than benefits conferred[19][20]

External Links

See Also

References

  1. Paul M., Gerss J., Schulze-Bahr E.; Role of programmed ventricular stimulation in patients with Brugada syndrome: a meta-analysis of worldwide published data. Eur Heart J. 28 2007:2126-2133.
  2. Cerrato N, Giustetto C, et al. Prevalence of Type 1 Brugada Electrocardiographic Pattern Evaluated by Twelve-Lead Twenty-Four-Hour Holter Monitoring. The American Journal of Cardiology.115(1). 2015. 52-56.
  3. Richter S., Sarkozy A., Veltmann C.; Variability of the diagnostic ECG pattern in an ICD patient population with Brugada syndrome. J Cardiovasc Electrophysiol. 20 2009:69-75.
  4. Shimizu W., Matsuo K., Takagi M.; Body surface distribution and response to drugs of ST segment elevation in Brugada syndrome: clinical implication of eighty-seven-lead body surface potential mapping and its application to twelve-lead electrocardiograms. J Cardiovasc Electrophysiol. 11 2000:396-404.
  5. Ikeda T., Abe A., Yusu S.; The full stomach test as a novel diagnostic technique for identifying patients at risk of Brugada syndrome. J Cardiovasc Electrophysiol. 17 2006:602-607.
  6. Shimeno K., Takagi M., Maeda K., Tatsumi H., Doi A., Yoshiyama M.; Usefulness of multichannel Holter ECG recording in the third intercostal space for detecting type 1 Brugada ECG: comparison with repeated 12-lead ECGs. J Cardiovasc Electrophysiol. 20 2009:1026-1031.
  7. Keller D.I., Huang H., Zhao J.; A novel SCN5A mutation, F1344S, identified in a patient with Brugada syndrome and fever-induced ventricular fibrillation. Cardiovasc Res. 70 2006:521-529.
  8. Makimoto H., Nakagawa E., Takaki H.; Augmented ST-segment elevation during recovery from exercise predicts cardiac events in patients with Brugada syndrome. J Am Coll Cardiol. 56 2010:1576-1584.
  9. Sarkozy A., Chierchia G.B., Paparella G.; Inferior and lateral electrocardiographic repolarization abnormalities in Brugada syndrome. Circ Arrhythm Electrophysiol. 2 2009:154-161.
  10. Junttila M.J., Brugada P., Hong K.; Differences in 12-lead electrocardiogram between symptomatic and asymptomatic Brugada syndrome patients. J Cardiovasc Electrophysiol. 19 2008:380-383.
  11. Take Y and Morita H. Fragmented QRS: What Is The Meaning? Indian Pacing Electrophysiol J. 2012 Sep-Oct; 12(5): 213–225.
  12. Morita H., Kusano K.F., Miura D.; Fragmented QRS as a marker of conduction abnormality and a predictor of prognosis of Brugada syndrome. Circulation. 118 2008:1697-1704.
  13. M Sharon, et al. ECG of the Month. Annals of Emergency Medicine. December 2019. 74(6);782-785
  14. Viskin S and Rosso R. Risk of Sudden Death in Asymptomatic Brugada Syndrome: Not as High as We Thought and Not as Low as We Wished…But the Contrary. J Am Coll Cardiol. 2010;56(19):1585-1588.
  15. Postema PG, Wolpert C, Amin AS, Probst V, Borggrefe M, Roden DM, et al. Drugs and Brugada syndrome patients: review of the literature, recommendations, and an up-to-date website (www.brugadadrugs.org). Heart Rhythm. 2009 Sep. 6(9):1335-41.
  16. M Sharon, et al. ECG of the Month. Annals of Emergency Medicine. December 2019. 74(6);782-785
  17. M Sharon, et al. ECG of the Month. Annals of Emergency Medicine. December 2019. 74(6);782-785
  18. M Sharon, et al. ECG of the Month. Annals of Emergency Medicine. December 2019. 74(6);782-785
  19. Sacher F., Probst V., Iesaka Y.; Outcome after implantation of a cardioverter-defibrillator in patients with Brugada syndrome: a multicenter study. Circulation. 114 2006:2317-2324.
  20. Rosso R., Glick A., Glikson M.; Outcome after implantation of cardioverter defibrillator in patients with Brugada syndrome: a multicenter Israeli study (ISRABRU). Isr Med Assoc J. 10 2008:435-439.