Overview
Definition
An inherited channelopathy associated with a high risk of ventricular fibrillation and sudden cardiac death in structurally normal hearts.
Epidemiology
More common in males, particularly of Asian descent. Often manifests in the 3rd or 4th decade of life.
Etiology & Risk Factors
- Autosomal dominant mutation in the SCN5A gene (codes for the cardiac sodium channel)
Clinical Symptoms
- Often asymptomatic until a lethal arrhythmia occurs
- Syncope
- Agonal nocturnal breathing
- Sudden cardiac death (often during sleep)
Clinical Approach
Diagnosis
- Classic ECG pattern: Coved ST-segment elevation >2mm followed by a negative T wave in the right precordial leads (V1-V3) (Type 1 pattern)
- Pattern can be unmasked by fever or sodium channel blockers (Flecainide, Procainamide)
Management
- Implantable Cardioverter Defibrillator (ICD) is the ONLY proven therapy to prevent sudden cardiac death
- Aggressively treat fevers
- Avoid triggering drugs (e.g., specific anesthetics, antidepressants)
Complications
- Ventricular Fibrillation
- Sudden Cardiac Death