Conversion of recent-onset atrial fibrillation to sinus rhythm: effects of different drug protocols

Pacing Clin Electrophysiol. 1998 Nov;21(11 Pt 2):2470-4. doi: 10.1111/j.1540-8159.1998.tb01203.x.


In a population of 417 hospitalized patients, the efficacy and safety of different drug regimens administered to convert atrial fibrillation (AF) of recent onset (< or = 7 days duration) to sinus rhythm were evaluated. All patients were in NYHA Class < or = 2, and free of heart failure. They were randomly allocated to treatment with placebo in 121 patients; i.v. amiodarone, 5 mg/kg bolus, followed by 1.8 g/24 hours in 51 patients; i.v. propafenone, 2 mg/kg bolus, followed by 0.0078 mg/kg/min in 57 patients; p.o. propafenone, 600 mg p.o. in a single dose in 119 patients; and p.o. flecainide, 300 mg p.o. in a single dose in 69 patients. All patients were continuously monitored by Holter ECG, and the number of conversions to sinus rhythm was measured at 1, 3, and 8 hours.

Results: (1) I.v. propafenone resulted in a higher conversion rate within 1 hour compared with the oral loading regimens of propafenone or flecainide, but the conversion rates at 3 and 8 hours were comparable, approximately 75% at 8 hours; 2) i.v. amiodarone was not different from placebo until 8 hours when it was associated with 57% of conversions; (3) conversion to sinus rhythm at 8 hours was observed in 37% of the placebo treated patients. Serious adverse effects occurred in few patients: two patients treated with flecainide and one treated with i.v. propafenone experienced left ventricular decompensation; one patient treated with placebo and two treated with flecainide had atrial flutter with rapid ventricular response. In conclusion, single-dose, oral loading with propafenone or flecainide are acceptable alternatives to conventional drug regimens in selected hospitalized patients. In addition, the measure of a placebo effect is mandatory in studies of recent-onset AF.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Amiodarone / administration & dosage
  • Amiodarone / therapeutic use
  • Anti-Arrhythmia Agents / administration & dosage
  • Anti-Arrhythmia Agents / therapeutic use*
  • Atrial Fibrillation / diagnosis
  • Atrial Fibrillation / drug therapy*
  • Dose-Response Relationship, Drug
  • Electrocardiography, Ambulatory
  • Female
  • Flecainide / administration & dosage
  • Flecainide / therapeutic use
  • Humans
  • Male
  • Middle Aged
  • Propafenone / administration & dosage
  • Propafenone / therapeutic use
  • Prospective Studies
  • Time Factors


  • Anti-Arrhythmia Agents
  • Propafenone
  • Flecainide
  • Amiodarone