Overview
Brugada syndrome is an inherited cardiac ion-channel disorder characterized by distinctive ECG patterns in the right precordial leads and an increased risk of malignant ventricular arrhythmias and sudden cardiac death (SCD), often in structurally normal hearts. The ECG phenotype is dynamic and may be concealed, unmasked, or modulated by fever, drugs, and autonomic tone.
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ECG Patterns of Brugada Syndrome
Type 1 (Diagnostic Pattern)
Key features
Coved ST-segment elevation ≥2 mm in ≥1 right precordial lead (V1–V3)
Followed by a negative T wave
J-point elevation with downsloping ST segment
Clinical significance
Only ECG pattern diagnostic of Brugada syndrome (when present spontaneously or induced by sodium-channel blocker)
High arrhythmic risk, especially if spontaneous and associated with symptoms
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Type 2 (Suggestive Pattern)
Key features
Saddleback ST elevation ≥2 mm
ST segment remains elevated ≥1 mm
Positive or biphasic T wave
Clinical significance
Not diagnostic
Requires further evaluation (lead repositioning, drug challenge)
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Type 3 (Suggestive Pattern)
Key features
Saddleback or coved morphology
ST elevation <2 mm
Clinical significance
Lowest specificity
Common in normal individuals
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Lead Placement Matters
Place V1 and V2 one or two intercostal spaces higher (2nd or 3rd ICS) to enhance sensitivity
High right precordial leads can convert type 2/3 to diagnostic type 1
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Dynamic Nature of the ECG
Brugada ECG patterns can be intermittent and influenced by:
Fever (most important reversible trigger)
Sodium-channel–blocking drugs (Class I antiarrhythmics, certain psychotropics)
Alcohol
Electrolyte disturbances
Increased vagal tone (rest, sleep)
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Diagnostic Criteria
Diagnosis requires:
Type 1 ECG pattern (spontaneous or drug-induced) Plus at least one of the following (for clinical diagnosis):
Documented ventricular fibrillation (VF) or polymorphic VT
Syncope of arrhythmic origin
Family history of SCD <45 years
Type 1 ECG in a first-degree relative
Inducible VT/VF on programmed stimulation (controversial)
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Differential Diagnosis of Right Precordial ST Elevation
Acute anterior or anteroseptal STEMI
Right ventricular hypertrophy
Early repolarization
Arrhythmogenic right ventricular cardiomyopathy (ARVC)
Acute pericarditis
Hyperkalemia
Pulmonary embolism
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Risk Stratification
High-risk features
Previous cardiac arrest or documented VF
Arrhythmic syncope
Spontaneous type 1 ECG
Male sex
Fragmented QRS, short ventricular refractory periods (supportive markers)
Lower-risk
Asymptomatic individuals with drug-induced type 1 ECG
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Management of Brugada Syndrome
1. General Measures (For All Patients)
Aggressive fever management (paracetamol, early treatment)
Avoid contraindicated drugs (updated lists on BrugadaDrugs.org)
Avoid excessive alcohol
Prompt treatment of electrolyte abnormalities
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2. Implantable Cardioverter-Defibrillator (ICD)
Indications
Survivors of cardiac arrest (Class I)
Documented spontaneous sustained VT/VF
Syncope with spontaneous type 1 ECG and high suspicion of arrhythmia
Not routinely recommended
Asymptomatic patients with only drug-induced type 1 ECG
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3. Pharmacological Therapy
Quinidine
Reduces Ito current, stabilizes epicardial action potential
Useful for:
Recurrent ICD shocks
Patients refusing or unsuitable for ICD
Electrical storms
Isoproterenol (IV)
Acute management of electrical storm
Especially effective in VF storms
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4. Catheter Ablation
Targeting arrhythmogenic substrate in the right ventricular outflow tract (RVOT)
Considered in:
Recurrent VF
Frequent ICD shocks despite medical therapy
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Special Situations
Fever-Induced Type 1 ECG
Treat fever aggressively
Hospital monitoring if type 1 pattern appears during fever
Counsel patients and families
Asymptomatic Patients
No ICD routinely
Close follow-up
Lifestyle and drug avoidance counseling
Family Screening
ECG screening of first-degree relatives
Consider genetic testing (SCN5A and others), though yield is modest
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Key Take-Home Points
Type 1 Brugada ECG is diagnostic
Type 2 and 3 are suggestive only
ECG pattern is dynamic and may require provocation
Fever is a major, preventable trigger
ICD remains the cornerstone of therapy for high-risk patients
Quinidine and ablation are important adjuncts in selected cases
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