A case of propafenone toxicity in the setting of dehydration and acute kidney injury.

Propafenone is a class 1C antiarrhythmic and is one of the first-line drugs used in the management of atrial fibrillation. Its toxicity is rare, yet potentially life-threatening. Common clinical findings could range from hypotension, dysrhythmias, and conduction disturbances to cardiac arrest. We present a case of an 80-year-old male who presented with generalized weakness and polyuria secondary to over-diuresis leading to dehydration. Electrocardiogram on admission showed a first-degree atrioventricular block, QRS complex widening, and QTC interval prolongation. These findings were attributed to propafenone toxicity in the setting of dehydration and increased serum propafenone concentration. In the case described the optimization of fluid status and holding propafenone temporarily led to rapid reversal of the electrocardiogram changes. Multiple treatment modalities have been attempted, but standard recommendations for propafenone toxicity management have yet to be established. This case stresses the importance of taking into consideration volume status and other reversible risk factors possibly contributing to propafenone toxicity.