Medicine · Arrhythmias and Conduction Disorders (ECG, Tachycardia, Heart Block)

A 22-year-old athlete collapses after vigorous exercise. He is resuscitated from ventricular fibrillation. ECG in normal sinus rhythm shows ST elevation in V1-V2 with right bundle branch block morphology, and the same pattern was previously documented. Genetic testing confirms a SCN5A mutation. The ONLY evidence-based secondary prevention is:

  • A Flecainide to suppress ventricular ectopy
  • B Amiodarone 200 mg daily
  • C Catheter ablation of right ventricular substrate
  • D Implantable cardioverter-defibrillator (ICD)
Correct answer: D. Implantable cardioverter-defibrillator (ICD)

Explanation

Brugada syndrome (SCN5A loss-of-function mutation causing sodium channel dysfunction) presents with a spontaneous Type 1 Brugada ECG pattern (coved-type ST elevation ≥2 mm in ≥1 right precordial lead V1-V3 with RBBB morphology) and risk of SCD from VF. In a survivor of cardiac arrest (secondary prevention), ICD implantation is the ONLY proven life-saving intervention (Class I indication, ESC 2022). Quinidine (not flecainide — which can paradoxically worsen Brugada) can be used as an adjunct to ICD in patients with electrical storms. Amiodarone does not reliably prevent VF in Brugada. Catheter ablation of epicardial RV outflow tract is investigational.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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