Pharmacological cardioversion with intravenous propafenone in atrial fibrillation

The efficacy and safety of intravenous propafenone for conversion of recent-onset and chronic atrial fibrillation was assessed in 46 patients. 40 with atrial fibrillation associated with or without structural heart disease (mean age 63 +/- 14 years) and 6 patients with atrial fibrillation related to the Wolff-Parkinson-White syndrome (mean age 34.8 +/- 13 years). Propafenone treatment was administered at 2 mg/kg over 15 minutes under continuous electrocardiographic monitoring. In 28 of 32 (87.5%) patients with paroxysmal and/or recent-onset atrial fibrillation a stable sinus rhythm was restored within 1 hour after propafenone (mean 17 +/- 11 minutes) and in only 3 of 8 (37.5%) with chronic atrial fibrillation (p < 0.05). Conversion to sinus rhythm was obtained in 5 of 6 (83.3%) patients with atrial fibrillation related ventricular preexcitation, mean time 21 +/- 12 minutes. Propafenone had an additional effect reducing mean heart rate (141 +/- 21 to 102 +/- 15 beat per minute, p < 0.05) and the shortest preexcited R-R intervals was increased, mean 231.6 +/- 27.8 to 355 +/- 37.2 milliseconds (p < 0.001) in cases associated with ventricular preexcitation. Dizziness, hypotension and transient conduction disturbances occurred in only one patient with rheumatic valvular heart disease: EF 40%. Propafenone is an effective and safe antiarrhythmic drug for converting paroxysmal and/or recent-onset atrial fibrillation of various origins with a more limited efficacy in chronic atrial fibrillation.