Propafenone Overdose Presenting With Brugada Phenocopy, QRS Widening, and Ventricular Fibrillation

Brugada phenocopy (BrP) denotes reversible Brugada-type electrocardiogram changes from transient triggers, requiring management distinct from congenital Brugada syndrome.

A 19-year-old man collapsed at home, regained consciousness in transit, and soon after emergency department arrival had recurrent syncope with ventricular fibrillation, which was defibrillated (200 J). The electrocardiogram showed PR interval approximately 200 milliseconds, QRS interval approximately 160 milliseconds, QTc interval approximately 489 milliseconds, lateral J-waves, and coved ST-segment elevation in V₁-V₂. A review of his phone confirmed propafenone ingestion (approximately 2.5 g over 3 days). Intravenous sodium bicarbonate led to rapid QRS interval narrowing and clinical stabilization.

The triad of diffuse conduction delay, V₁-V₂ coved morphology, and J-waves in acidemia with dose-verified exposure supports drug-induced BrP. Early bicarbonate reverses sodium-channel blockade; normalization and normal cardiac magnetic resonance argue against a fixed substrate, so implantable cardioverter-defibrillator is unnecessary.

BrP resolves after correcting reversible triggers. In sodium-channel blocker toxicity with QRS interval widening, early sodium bicarbonate is first-line therapy.