[Propafenone dose for emergency room conversion of paroxysmal atrial fibrillation]

Paroxysmal atrial fibrillation (AF), a frequent cause of repeated hospitalization, is effectively treated with propafenone. The time to conversion to sinus rhythm is a consideration when managing AF in the emergency room. We investigated the conversion rates of paroxysmal AF by 3 different oral propafenone (P) regimens, in terms of time to conversion. 188 patients with onset of AF within 48 hours were treated with propafenone (P): 48 received 600 mg as a first oral dose followed after 8 hrs by 150 mg (Group A); 82 received 300 mg as a first dose, followed by the same dose 3 and again 8 hrs later (B); 58 received 150 mg every 3 hrs, up to a total dose of 600 mg (C). P was stopped when sinus rhythm was achieved. Rates of conversion to sinus rhythm after 3 hrs in the 3 groups were: 46%, 41% and 26% respectively; after 8 hrs: 77%, 78% and 70%; and after 12 hrs: 81%, 84% and 76%. Treatment was discontinued in 8. There was excessive QRS widening (> 25% of the basal value) in 1 in group A, 1 in group B and 2 in group C; wide-QRS tachycardia occurred in 4 in group B. In Group A there was a higher rate of early successful conversion, with a lower incidence of side-effects than with the other regimens.