Brugada pattern masquerading as ST-segment elevation myocardial infarction in flecainide toxicity

Flecainide (a class 1c antiarrhythmic) produces a dose-dependent decrease in intracardiac conduction. Its well known common electrocardiographic effects are prolongation of PR and QT intervals and the QRS complex duration. We report a case of flecainide toxicity in an elderly female who presented with a type 1 Brugada pattern who essentially had a previously normal ECG pattern on therapeutic dose of flecainide therapy. The case describes a rare electrocardiographic abnormality induced by flecainide toxicity which otherwise could be easily misinterpreted as a ST-segment elevation myocardial infarction (STEMI) without lack of expertise and high clinical suspicion.