Definition
Brugada syndrome is an inherited cardiac channelopathy characterized by a distinctive ECG pattern in the right precordial leads (V1–V3) and an increased risk of polymorphic ventricular tachycardia and sudden cardiac death, often in the absence of structural heart disease.
---
Epidemiology
More common in males (≈8–10:1)
Higher prevalence in Southeast Asia
Often presents in young to middle-aged adults
Sudden cardiac death may be the first manifestation
---
Genetic and Pathophysiology
Most commonly linked to loss-of-function mutations in SCN5A
Reduced inward sodium current (INa)
Creates transmural voltage gradients in the right ventricular outflow tract
Predisposes to phase 2 reentry and malignant ventricular arrhythmias
---
ECG Patterns (Cornerstone of Diagnosis)
Type 1 (Diagnostic)
Coved ST-segment elevation ≥2 mm in V1–V3
Followed by a negative T wave
Can be spontaneous or drug-induced
Type 2
Saddleback ST elevation
ST elevation ≥2 mm, trough ≥1 mm
Not diagnostic alone
Type 3
Saddleback or coved pattern with ST elevation <1 mm
Nonspecific
> Only Type 1 ECG confirms the diagnosis.
---
Lead Placement Tip
Recording V1–V2 in higher intercostal spaces (2nd–3rd) increases diagnostic yield
Particularly useful in concealed cases
---
Clinical Presentation
Syncope (often nocturnal or at rest)
Seizure-like episodes
Nocturnal agonal respiration
Sudden cardiac arrest
Many patients remain asymptomatic
---
Triggers That Unmask ECG or Arrhythmias
Fever (most important reversible trigger)
Sodium channel–blocking drugs
Alcohol excess
Electrolyte disturbances
Cocaine and certain psychotropic medications
---
Diagnostic Criteria
Diagnosis requires:
Type 1 Brugada ECG pattern (spontaneous or drug-provoked) Plus at least one of the following:
Documented ventricular fibrillation or polymorphic VT
Family history of sudden cardiac death <45 years
Syncope of suspected arrhythmic cause
Inducible VT/VF on electrophysiology study
---
Risk Stratification
High-risk features
Previous cardiac arrest
Syncope with spontaneous Type 1 ECG
Documented ventricular arrhythmias
Lower risk
Asymptomatic patients
Drug-induced Type 1 pattern only
---
Management
Implantable Cardioverter-Defibrillator (ICD)
Indicated in survivors of cardiac arrest
Indicated in syncope with spontaneous Type 1 ECG
Only proven therapy to prevent sudden death
Medical Therapy
Quinidine may reduce ventricular arrhythmias
Used in recurrent ICD shocks or when ICD is not feasible
Fever Management
Aggressive antipyretic therapy is essential
Fever can precipitate fatal arrhythmias
---
Drugs to Avoid
Class I antiarrhythmics (flecainide, procainamide)
Certain antidepressants and antipsychotics
Some anesthetic agents
Cocaine and excessive alcohol
(Reference lists should always be checked before prescribing)
---
Brugada Phenocopy
ECG pattern mimicking Brugada syndrome
Caused by metabolic disturbances, ischemia, or mechanical compression
Resolves after treating the underlying cause
No genetic basis, no long-term arrhythmic risk
---
Prognosis
Highly variable
Asymptomatic individuals may remain event-free
Risk persists lifelong
Early recognition and appropriate risk-based therapy are crucial
---
Key Takeaways
Type 1 ECG is diagnostic
Fever is a major reversible trigger
ICD is the only definitive life-saving therapy
Not all Brugada ECG patterns equal Brugada syndrome
Careful risk stratification prevents overtreatment and undertreatment
Comments
Post a Comment
Drop your thoughts here, we would love to hear from you