Brugada syndrome

Introduction

The Brugada syndrome is an autosomal dominant genetic disorder with variable expression characterized by abnormal findings on the surface electrocardiogram in conjunction with an increased risk of ventricular tachyarrhythmias and sudden cardiac death. 

First described in 1992 by the Brugada brothers, demonstrating high incidence in Southeast Asia, the mean age of sudden death is 41.

ECG features

Some form of a pseudo-right bundle branch block and persistent ST segment elevations in leads V1 to V2.

Brugada pattern: patients with typical ECG features who are asymptomatic and have no other clinical criteria.

Brugada syndrome: patients with typical ECG features who have experienced sudden cardiac death or a sustained ventricular tachyarrhythmia, or who have one or more of the other associated clinical criteria (syncope, seizures, and nocturnal agonal respiration due to polymorphic ventricular tachycardia or VF).


Type 1 (“coved type”) (Figure 1A): This alteration is the only diagnostic pattern for BrS. It is characterized by an ST-segment elevation ≥2 mm in ≥1 right precordial lead (V1 to V3), followed by an rʹ-wave and a concave or straight ST segment. The descending ST segment crosses the isoelectric line and is followed by a negative and symmetric T-wave.Type 2 Brugada ECG pattern -  the ST segment has a "saddle back" ST-T wave configuration

Type 2 (“saddle-back type”) (Figure 1B): This ECG anomaly is only suggestive of BrS. It is characterized by an ST-segment elevation ≥0.5 mm (generally ≥2 mm in V2) in ≥1 right precordial lead (V1 to V3), followed by a convex ST. The rʹ-wave may or may not overlap the J point, but it has a slow downward slope. The ST segment is followed by a positive T-wave in V2 and is of variable morphology in V1. 

Figure 1

https://ars.els-cdn.com/content/image/1-s2.0-S0735109718353622-gr1.jpg
Brugada J, Campuzano O, Arbelo E, et al. Present Status of Brugada Syndrome: JACC State-of-the-Art Review. J Am Coll Cardiol 2018; 72:1046.


Provoking factors

  • Fever
  • Ischaemia
  • Multiple Drugs (Sodium channel blockers ETA
  • Nitrates
  • Cholinergic stimulation
  • Cocaine
  • Alcohol
  • Hypokalemia
  • Hypothermia

Where to put chest leads in Brugada syndrome? The placement of the right precordial leads in more cranial positions (in the 3rd or 2nd intercostal spaces) increases sensitivity in some patients due to the variable anatomical correlation between the right ventricular outflow tract and V1 to V2 in the standard position.

Drug challenge
-
Flecainide – 2 mg/kg over 10 minutes intravenously or 400 mg orally
- Procainamide – 10 mg/kg over 10 minutes intravenously
- Ajmaline – 1 mg/kg over 5 minutes intravenously

Treatment
-
Full list medications that have to be avoided: www.brugadadrugs.org
-
ICD implantation
- Medical treatment - quinidine, amiodarone
- Catheter ablation


ECG 1A Patient admitted after CPR for VF, ECG on admission with suspicious ST elevations in V1-V2

Brugada on admission.jpg

ECG 1B Ajmaline test (after 10 minutes) – positive Brugada 1.type in V1-V3 (coved type)

Brugada 10min.jpg

ECG 2 Patient with a history of syncope and Brugada syndrome features on ECG


Reference

  1. Priori SG, Wilde AA, Horie M, et al. HRS/EHRA/APHRS expert consensus statement on the diagnosis and management of patients with inherited primary arrhythmia syndromes: document endorsed by HRS, EHRA, and APHRS in May 2013 and by ACCF, AHA, PACES, and AEPC in June 2013. Heart Rhythm 2013; 10:1932.
  2. Brugada J, Campuzano O, Arbelo E, et al. Present Status of Brugada Syndrome: JACC State-of-the-Art Review. J Am Coll Cardiol 2018; 72:1046.
  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; 20:1391.
  4. Bayés de Luna A, Brugada J, Baranchuk A, Borggrefe M, Breithardt G, Goldwasser D, Lambiase P, Riera AP, Garcia-Niebla J, Pastore C, Oreto G, McKenna W, Zareba W, Brugada R, Brugada P. Current electrocardiographic criteria for diagnosis of Brugada pattern: a consensus report. J Electrocardiol. 2012 Sep;45(5):433-42. doi: 10.1016/j.jelectrocard.2012.06.004. Erratum in: J Electrocardiol. 2013 Jan-Feb;46(1):76. PMID: 22920782.
  5. Nagase S, Hiramatsu S, Morita H, Nishii N, Murakami M, Nakamura K, Kusano KF, Ito H, Ohe T. Electroanatomical correlation of repolarization abnormalities in Brugada syndrome: detection of type 1 electrocardiogram in the right ventricular outflow tract. J Am Coll Cardiol. 2010 Dec 14;56(25):2143-5. doi: 10.1016/j.jacc.2010.06.050. PMID: 21144977.
  6. Brugada J, Pappone C, Berruezo A, Vicedomini G, Manguso F, Ciconte G, Giannelli L, Santinelli V. Brugada Syndrome Phenotype Elimination by Epicardial Substrate Ablation. Circ Arrhythm Electrophysiol. 2015 Dec;8(6):1373-81. doi: 10.1161/CIRCEP.115.003220. Epub 2015 Aug 19. PMID: 26291334.
  7. Rudic B, Chaykovskaya M, Tsyganov A, Kalinin V, Tülümen E, Papavassiliu T, Dösch C, Liebe V, Kuschyk J, Röger S, El-Battrawy I, Akin I, Yakovleva M, Zaklyazminskaya E, Shestak A, Kim S, Chmelevsky M, Borggrefe M. Simultaneous Non-Invasive Epicardial and Endocardial Mapping in Patients With Brugada Syndrome: New Insights Into Arrhythmia Mechanisms. J Am Heart Assoc. 2016 Nov 14;5(11):e004095. doi: 10.1161/JAHA.116.004095. PMID: 27930354; PMCID: PMC5210320.
  8. UpToDate Brugada syndrome (Epidemiology and pathogenesis, Clinical presentation, diagnosis, and evaluation, Prognosis, management, and approach to screening)