Brugada Syndrome - Diagnosis and Management

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Raja Selvaraj, JIPMER

What is it

  • Inherited disease, first described in 1992
  • Autosomal dominant
  • Atypical RBBB with ST elevation in right precordial leads
  • Malignant arrhythmias

Prevalence and demographics

  • Higher incidence in South East Asia, esp Thailand, Philippines and Japan
  • About 1:2000 population
  • 80% of adult patients are males
  • About 20% of sudden death with normal heart
  • Triggers - night, large meal, fever

Pathogenesis

  • Was initially considered a sodium channelopathy with repolarization abnormalities
  • Sodium, Calcium and Potassium channel genetic abnormalities identified
  • ? Polygenic
  • Repolarization-depolarization abnormalities
  • Common phenotypic expression of various abnormalities

Diagnosis

Presentation

  • Males, third / fourth decade
  • Resuscitated sudden death, syncope, VF
  • Typically at night
  • Mean age at death around 40 yrs
  • Infants and children - symptoms with fever
  • Monomorphic VT

ECG findings

brugada_ecg.jpg

Wilde AA et al. Proposed diagnostic criteria for the Brugada syndrome. Circulation 2002; 106:2514-19

Other ECG findings

  • PR prolongation
  • Fragmented QRS
  • Atrial fibrillation
  • Sinus bradycardia / atrial standstill

Diagnostic challenge

  • Typical symptoms and type I ECG
  • Symptoms, not type I ECG
  • No symptoms, type I ECG

Suspicious symptoms, not type I ECG

Drug provocation

  • IV Ajmaline - short acting, higher sensitivity
  • IV Flecainide
  • Oral flecainide (ref)

Drug provocation

  • Monitoring
    • 3 hrs with Ajmaline
    • Longer with flecainide
  • Isoprenaline for arrhythmias
  • Chest electrodes one space higher

Electrode position

  • Electrodes one space higher (V1-V3 in 2nd to 3rd space)
  • 12 lead holter with modified V1-V3 and look for changes during nocturnal bradycardia

Type I ECG, no symptoms

Misdiagnosis

  • Following cardioversion
  • Early repolarization
  • Athletes heart
  • RBBB
  • Prinzmetal angina
  • Hypothermia

2005 consensus statement - Clinical findings required in addition to ECG

  • Documented ventricular fibrillation (VF) / Polymorphic VT
  • Family history of sudden cardiac death at <45 years
  • Coved-Type ECG in family members
  • Inducibility of VT with programmed stimulation
  • Syncope or nocturnal agonal respiration (attributed to self-terminating polymorphic VT or VF)

Brugada Syndrome: Report of the Second Consensus Conference. Circulation. 2005;111:659-670

2011 HRS / EPHRA / APHRS consensus

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HRS/EHRA/APHRS Expert Consensus Statement on the Diagnosis and Management of Patients with Inherited Primary Arrhythmia Syndromes. Heart Rhythm 2013;10(12):1932-1963

Role of genetic testing

  • Generally not considered useful
  • Testing for 12 genes equivalent to clinical criteria

Crotti et al. Spectrum and prevalence of mutations involving BrS1- through BrS12-susceptibility genes in a cohort of unrelated patients referred for Brugada syndrome genetic testing: implications for genetic testing J Am Coll Cardiol., 60 (2012), pp. 1410-1418

Outcomes - Annual event rate (1)

  • Cardiac arrest - 7.7%
  • Syncope - 1.9 %
  • Asymptomatic spontaneous type I ECG - 0.5%

Probst et al. Long-term prognosis of patients diagnosed with Brugada syndrome: Results from the FINGER Brugada Syndrome Registry Circulation., 121 (2010), pp. 635-643

Management

Lifestyle measures

  • Avoid "Brugada" drugs - brugadadrugs.org
  • Prompt treatment of fever
  • Avoid excess alcohol
  • Avoid big carbohydrate meals at night

Who should get an ICD ?

  • Resuscitated cardiac arrest
  • Cardiac syncope

Consensus recommendation

icd_recommendations.png

HRS/EHRA/APHRS Expert Consensus Statement on the Diagnosis and Management of Patients with Inherited Primary Arrhythmia Syndromes. Heart Rhythm 2013;10(12):1932-1963

Other risk markers

  • Family history of sudden death not an indication
  • Spontaneous type I ECG higher risk than provoked type I ECG
  • QRS fragmentation, RV ERP < 200 ms, history of syncope, atrial fibrillation

Drugs

  • Quinidine effective for long term
  • Other drugs - Cilostazol, Tedisamil
  • Isoprenaline infusion - for storm

Ablation

  • First started with ablation of triggering PVCs
  • Abnormal substrate identified in epicardial RVOT and ablated
  • Abolition of ECG changes, reduction in clinical episodes

Nademanee K et al. Prevention of ventricular fibrillation episodes in Brugada syndrome by catheter ablation over the anterior right ventricular outflow tract epicardium. Circulation 2011;123:1270–1279

Illustrative case

Presentation

  • 45 / Male
  • Syncope at home when he woke up and walked to bathroom
  • No previous syncope
  • Unexplained sudden death in brother

ECG at presentation at local hospital

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ECG on presentation at JIPMER

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Initial diagnosis

  • Paroxysmal AF
  • Syncope due to AF / Vasovagal

2 hrs post oral flecainide

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2 hrs post oral flecainide challenge

2hrs_flecainide_va.jpg

  • Polymorphic VT - defibrillation, Isoprenaline
  • Diagnosed as BrS, AICD implanted
  • Recurrent VF with shocks once a month
  • no response to Cilostazol

Endo - epicardial mapping

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Ablation

  • Partial response to ablation
  • One episode / yr now, ICD in situ

Summary

  • Brugada syndrome is a challenging condition to identify and treat
  • Typical symptoms with type I ECG - ICD is indicated
  • Look at serial ECGs for subtle signs in patients with symptoms, consider drug provocation, higher position of electrodes
  • Asymptomatic type I ECG - only lifestyle changes
  • A disease that we are still learning about