Acute propafenone toxicity after two exposures at standard dosing.

A 72-year-old woman presented with a decreased level of consciousness and hypotension. The initial electrocardiogram demonstrated atrial fibrillation with a wide QRS complex. Her medical history revealed that she had just been started on propafenone. A diagnosis of propafenone toxicity was made and sodium bicarbonate was administered. A rare phenomenon in which toxicity occurred at therapeutic dosing is reported. Acute propafenone toxicity manifests in a wide range of organ systems; in particular, cardiovascular compromise in the form of hypotension, bradycardia and QRS widening can occur. Sodium bicarbonate therapy is advocated to directly counteract the toxic effects of propafenone. In the case described, this treatment resulted in rapid normalization of the QRS duration and stabilization of the hemodynamic profile.