Arrhythmogenic effect of flecainide toxicity

Flecainide is a class 1C antiarrhythmic drug especially used for the management ofsupraventricular arrhythmia. In overdose cases, flecainide can induce life treating ventriculararrhythmias and cardiogenic shock. We report the case of a 72-year-old woman admitted toour intensive care unit for a regular monomorphic wide complex tachycardia (QRS duration240 ms, right bundle branch block and superior axis morphology) without apparent P waves.Clinical examination showed slight left congestive heart failure signs without cardiogenicshock. An intravenous bolus of 10 mg adenosine 5’-triphosphate (ATP) was ineffective to stopthe tachycardia. The diagnosis of ventricular tachycardia induced by flecainide overdose wasconsidered. 500 mL of intravenous 84‰ sodium bicarbonate was administrated. The patient’sQRS narrowed immediately and 12-lead ECG showed sinus rhythm. Blood samples confirmed theflecainide overdose and the clinical status progressively improved