Conversion of recent-onset atrial fibrillation to sinus rhythm: effects of different drug protocols.
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.
Boriani
G
G
Institute of Cardiology, University of Bologna, Italy. cardio1@almadns.unibo.it
Biffi
M
M
Capucci
A
A
Botto
G
G
Broffoni
T
T
Ongari
M
M
Trisolino
G
G
Rubino
I
I
Sanguinetti
M
M
Branzi
A
A
Magnani
B
B
D000638:Amiodarone / Q000008:administration & dosage / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000188:drug therapy*; D004305:Dose-Response Relationship, Drug; D015716:Electrocardiography, Ambulatory; D005260:Female; D005424:Flecainide / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D011405:Propafenone / Q000008:administration & dosage / Q000627:therapeutic use; D011446:Prospective Studies; D013997:Time Factors
D000889:Anti-Arrhythmia Agents; D011405:Propafenone; D005424:Flecainide; D000638:Amiodarone