Brugada syndrome ✅

Related Subjects: |Brugada Syndrome |Long QT syndrome (LQTS) Acquired |Long QT syndrome (LQTS) Congenital |Torsades de Pointes |Ventricular Fibrillation |Ventricular Tachycardia |Resuscitation - Adult Tachycardia Algorithm |Automatic Implantable Cardioverter Defibrillator (AICD)

⚡ Brugada syndrome is an inherited arrhythmia syndrome associated with an increased risk of ventricular fibrillation and sudden cardiac death. 💔 In patients at high risk - especially those with previous cardiac arrest or likely arrhythmic syncope - an implantable cardioverter-defibrillator (ICD) is the main life-saving treatment. 🧬 Family screening, fever management, and strict avoidance of trigger drugs are essential parts of care.

ℹ️ About

• Definition: Genetic channelopathy causing malignant ventricular arrhythmias, diagnosed by characteristic ECG patterns.
• Incidence: ~1–6 per 1000; higher in Southeast Asian men (8:1 male:female).
• History: Described in 1992 by Pedro & Josep Brugada; genetic links later identified by their brother Ramon.

🧬 Genetics

• SCN5A mutation = most common (~30% of cases), encodes NaV1.5 sodium channel.
• Other genes: CACNA1C, CACNB2, SCN10A (less frequent).
• Inheritance: autosomal dominant with variable expression.

⚙️ Aetiology & Pathophysiology

• Defective sodium influx → imbalance in cardiac action potential → arrhythmias.
• Right ventricular outflow tract (RVOT) most affected → explains ECG changes.
• Loss-of-function sodium channel mutations on chromosome 3 (SCN5A) in many cases.

📑 Types of Brugada Syndrome

• Type 1: Classic “coved” ST elevation ≥2 mm in V1–V3 with inverted T wave → diagnostic.
• Type 2/3: “Saddleback” ST elevation → not diagnostic; may need drug provocation.

🩺 Clinical Presentation

• 💔 Sudden cardiac arrest (often during sleep/rest).
• 😵 Syncope, often with fever, exertion, or stress.
• 😮‍💨 Nocturnal agonal breathing → “sudden unexplained nocturnal death syndrome (SUNDS).”
• 🧩 Asymptomatic → found on family ECG or incidental screening.

🔍 Investigations

• 📈 ECG: ST elevation in V1–V3 ± RBBB pattern. QTc normal.
• 💉 Provocation: sodium channel blockers (ajmaline/flecainide) to unmask type 1 (done only in hospital).
• 🧬 Genetic testing: SCN5A mutation; guides family screening.
• 🩻 Imaging (Echo, CMR): normal structure (purely electrical disease).
• 📟 Holter/EP study: may detect inducible VT/VF.

☠️ Risk Factors for Sudden Cardiac Death (SCD)

💊 Management

• Cardiac arrest: immediate ALS with CPR and defibrillation.
• ICD: indicated for secondary prevention after aborted cardiac arrest, and for selected high-risk patients after specialist inherited arrhythmia assessment.
• Lifestyle / trigger avoidance: treat fever urgently, avoid excess alcohol, avoid recreational drugs, and avoid drugs listed as unsafe on BrugadaDrugs.org.
• Drug therapy: quinidine may be used in selected patients, especially recurrent ventricular arrhythmias or electrical storm, usually under specialist guidance.
• Ablation: considered in specialist centres for recurrent VF / electrical storm despite other treatment.
• Family screening: first-degree relatives should have specialist assessment with ECG ± genetic testing if a familial pathogenic variant is known.

📚 Teaching Pearls

👉 Think of Brugada in any unexplained syncope, nocturnal arrest, or suspicious family history. 👉 It is a functional disease (electrical, not structural) → echo/MRI normal. 👉 Fever is dangerous: educate patients & families to treat aggressively. 👉 In the UK, all suspected cases should be referred to an Inherited Cardiac Conditions clinic for risk stratification & family screening. 👉 Key exam tip: the coved ST elevation in V1–V3 is diagnostic (Type 1).

🔖 References

• BrugadaDrugs.org – Safe/Unsafe Drug List
• AHA/ACC/HRS Guidelines (2020)

🩺 Case 1 - Syncope in a Young Man

A 29-year-old man is brought after a syncopal episode while resting at night. Family history reveals a brother who died suddenly aged 32. ECG shows coved ST-segment elevation in V1–V3 consistent with type 1 Brugada pattern. Management: 🚑 Refer urgently to cardiology. Implantable cardioverter-defibrillator (ICD) indicated in symptomatic Brugada with syncope/ventricular arrhythmia. Lifestyle advice: avoid excessive alcohol, fever, and dehydration. Avoid: ❌ Sodium channel–blocking drugs (e.g. flecainide, procainamide, tricyclic antidepressants); avoid assuming “normal” echo excludes risk.

🩺 Case 2 - Incidental ECG Finding

A 40-year-old man undergoes ECG during a work medical, showing saddleback ST elevation in V2 suggestive of Brugada type 2 pattern. He is asymptomatic, with no family history of sudden cardiac death. Management: 🩺 Cardiology referral for further risk stratification (provocative drug testing with ajmaline/flecainide, genetic testing, electrophysiology studies). Lifestyle advice: prompt treatment of fever, avoid contraindicated drugs. Avoid: ❌ Immediate ICD insertion without symptoms or high-risk features; avoid missing the opportunity for family screening.

📊 ECG Findings