EKG Rounds

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EKG Rounds

• Elizabeth Haney
• 17 August 2006

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Case

• 26 yo Caucasian male presents to your ED with hx
  of a single syncopal episode.
• Witnessed, lt1minute, no Seizure activity, alert
  following event.
• T 37.3/ HR 80reg/ BP 124/76/ RR 12
• O2sat 99RA/ BG 6.2
• Asymptomatic in ED, wants to go home!
• What else would you like to know?

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Additional History

• Assoc. with brief episode of palpitations prior
  to syncope
• No SOB, Chest Pain, N/V, HA
• PMHx healthy
• Meds nil
• No street drug use
• FHx No known CAD/stroke/seizure/syncope.
  Father died in his sleep at 34.

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His EKG

• Any takers on Dx?

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Brugada Syndrome
Twelve-lead surface EKG showing typical pattern
of right bundle-branch block and ST-segment
elevation of "coved type" in leads V1 to V3 in a
patient identified after a syncopal episode
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Brugada Syndrome

• First described in 1992 by Pedro and Josep
  Brugada
• New syndrome assoc. w/ SCD in pts w/
  structurally normal hearts no evidence of CAD
• Pts had a distinct set of EKG abnormalities
• -RBBB pattern, and persistent ST-segment
  elevation in the right precordial leads (V1-3).

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Epidemiology

• Prevalence ranges vary 0.7-1.0 in Japanese
  studies, 0.6 in Finnish study, 0.4 in US study.
• MaleFemale ratio up to 91.
• More common in Asian populations.

Up To Date
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Genetics

• Autosomal Dominant inheritance
• 15 to 30 of patients with the Brugada syndrome,
  mutations have been found in SCN5A, the cardiac
  sodium channel a-subunit gene located on
  chromosome 3

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Structural Abnormalities

• BS not usually assoc. w/ structural heart dz
• Evidence supporting subtle microscopic
  abnormalities incl. localized myocarditis or
  microaneurysms.
• Frustaci et al., Cardiac histological substrate
  in patients with clinical phenotype of Brugada
  Sundrome. Circ. 2005 Dec 13112(24)3680-7.
• 18 pts in study, 14 w/ RV myocarditis, 7 w/ RV
  microaneurysms

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3 Patterns of ST Elevation

• Type 1 elevated ST segment ( gt2 mm) descends
  with an upward convexity to an inverted T wave.
  "coved type" Brugada pattern.
• Type 2 and type 3 patterns have a "saddle back"
  ST-T wave configuration, with the elevated ST
  segment descends toward the baseline, then rises
  again to an upright or biphasic T wave. The ST
  segment is elevated 1 mm in type 2 and lt1 mm in
  type 3.

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Brugada Waves 3 Types
Coved ST segments w/ T wave inversion

• Saddleback ST segments
• Type 2
• Positive or biphasic T wave
• 1mmSTE
• Type 3
• Positive T wave
• lt1mm STE

Z Kardiol 2004 93784790 Thanks Dr. Haager
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Differential Dx

• EKG findings alone not diagnostic.
• DDx
• RV pathology
• Compression (tumor, hemopericardium)
• Inferior MI, RV ischemia, Cardiac contusion
• RBBB, LVH
• Arrhythmogenic right ventricular cardiomyopathy
• Drugs class IA (procainamide), IC (propafenone,
  flecainide), cocaine, TCAs, and more
• Hyperkalemia, hypercalcemia

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Brugada Pattern vs Syndrome

• Brugada Pattern EKG findings without other
  clinical criteria
• Brugada Syndrome typical EKG findings with
  other clinical criteria

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Clinical Spectrum
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Clinical Manifestations

• Related to life-threatening ventricular
  arrhythmias.
• SCD occurs in as many as 1/3rd of pts!
• Arrhythmic events generally occur between ages of
  22-65.
• More common at night and during sleep, usually
  not related to exercise.

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Diagnostic Criteria Type I

• In evolution.
• Strongly consider in pts that meet the following
  criteria
• Type I
• EKG pattern of type 1 ST segment elevation (coved
  type) in gt1 lead of V1-V3
• and 1 of
• Documented VF
• Self-terminating polymorphic VT
• Family Hx of SCD lt45
• Other Family members w/ Brugada ECG pattern
• EPS inducibility of VT
• Unexplained syncope suggestive of a
  tachyarrhythmia
• Nocturnal agonal respirations
• Wilde et al. Eur Heart J 2002231648

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Diagnostic Criteria Type 2 3

• Type 2 or 3
• EKG pattern of type 2 or 3 ST segment elevation
  (saddle-back type) in gt1 lead of V1-V3, with
  conversion to type 1 following challenge w/ a
  sodium channel blocker
• And1 of
• Documented VF
• Self-terminating polymorphic VT
• Family Hx of SCD lt45
• Other Family members w/ Brugada ECG pattern
• EPS inducibility of VT
• Unexplained syncope suggestive of a
  tachyarrhythmia
• Nocturnal agonal respirations

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Proposed Work-Up
19
(No Transcript)
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Treatment

• Refer for EP studies
• ICD placement
• When provided with an ICD, mortality at 10-year
  follow-up has been 0.
• Quinidine (sodium channel blocker) research shows
  promise. Currently may have role for pts with
  ICD and frequent discharges (consider amiodarone,
  quinidine or hydroquinidine). Uptodate.com

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Take Home

• Be familiar with the EKG manifestations of
  Brugada syndrome to ensure early diagnosis and
  prompt referral.

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References

• Zipes Braunwald's Heart Disease A Textbook of
  Cardiovascular Medicine, 7th ed.
• Brugada P, Brugada J Right bundle branch block,
  persistent ST segment elevation and sudden
  cardiac death a distinct clinical and
  electrocardiographic syndrome. J Am Coll Cardiol
  1992201391-1396
• Littmann et al., Brugada syndrome and Brugada
  sign Clinical spectrum with a guide for the
  clinician ,American Heart Journal, 145768-778
• Frustaci et al., Cardiac histological substrate
  in patients with clinical phenotype of Brugada
  Sundrome. Circ. 2005 Dec 13112(24)3680-7.
• Wilde et al., Proposed diagnostic criteria for
  the Brugada syndrome. Eur Heart J 2002 231648
• Mattu et al., The Brugada Syndrome, Am J Emerg
  Med 200321146-151
• Uptodate.com
• J.,R., and P. Brugada, Determinants of Sudden
  Cardiac Death in Individuals With the
  Electrocardiographic Pattern of Brugada Syndrome
  and No Previous Cardiac Arrest. Circ. Dec. 2003
  108 3092-3096

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• Pts w/ ECG diagnostic of Brugada syndrome and no
  previous cardiac arrest have an 8 risk of SCD
  during a short-term follow-up period of 2 years.
  
• Lowest-risk group no syncopal episodes,
  diagnostic ECG only with drug challenge, and
  noninducibility during programmed ventricular
  stimulation (0.5 incidence of events).
• Highest-risk group combo of a previous history
  of syncope, a spontaneously abnormal ECG, and
  inducible sustained arrhythmias during programmed
  ventricular stimulation (27.2 incidence of
  events).
• J.,R., and P. Brugada, Determinants of Sudden
  Cardiac Death in Individuals With the
  Electrocardiographic Pattern of Brugada Syndrome
  and No Previous Cardiac Arrest. Circ. Dec. 2003
  108 3092-3096