PROPAFENONE FOR CONVERSION OF RECENT-ONSET ATRIAL-FIBRILLATION - A CONTROLLED COMPARISON BETWEEN ORAL LOADING DOSE AND INTRAVENOUS ADMINISTRATION

Study objective: To compare placebo vs two different regimens of propa fenone administration-intravenous administration or short-term oral lo ading-in converting recent-onset atrial fibrillation to sinus rhythm. Design: Single-blind placebo-controlled study. Patients: Eighty-seven patients with atrial fibrillation of recent onset (less than or equal to 7 days' duration) admitted to the hospital without signs of organic heart disease (n=42) or with systemic hypertension without signs or s ymptoms of heart failure (n=45). The patients were assigned randomly t o treatment with intravenous propafenone (29 patients), oral propafeno ne (29 patients), or placebo (29 patients). Interventions: Administrat ion of propafenone intravenously (2-mg/kg bolus followed by 0.0078 mg/ kg/min) or as short-term oral loading (600 mg orally single dose). Pat ients were submitted to Holter monitoring and conversion to sinus rhyt hm was evaluated at 1, 3, and 8 h. Results: Conversion to sinus rhythm was obtained within 1 h in 28% with intravenous propafenone, in 3% wi th oral propafenone, and in 3% with placebo, At 3 h, the efficacy of i ntravenous propafenone (41%) and of oral propafenone (55%) were statis tically superior to placebo (10% of conversions) and at 8 h either int ravenous or oral propafenone were effective in almost two thirds of th e patients with a statistical difference vs placebo, whose efficacy wa s 24%, No major side effects were observed. Conclusions: Propafenone a s an oral loading dose is an efficacious and fast way of treating atri al fibrillation of recent onset and due to its simplicity of administr ation and safety can be preferred to the intravenous route.