Abstract
BACKGROUND: Antiarrhythmic drugs commonly used in atrial fibrillation management are associated with variable clinical responses and proarrhythmic properties. CASE SUMMARY: A 53-year-old woman presented with a wide-complex tachycardia. Electrocardiogram after amiodarone administration revealed a flecainide-induced atrial flutter with 1:1 AV conduction and pacemaker interrogation revealed undersensing of presenting ventricular rates at 230 beats/min. DISCUSSION: Flecainide therapy has been well-described to organize AF into AFL that is predisposed to 1:1 AV conduction. This case underscores a concerning limitation in the detection of potentially life-threatening arrhythmias with some nominal pacemaker devices.