Intravenous administration of propafenone

Amiodarone versus propafenone for conversion of chronic atrial fibrillation: results of a randomized, controlled study

OBJECTIVES

The purpose of this study was to investigate the efficacy and safety of amiodarone and propafenone in the conversion of chronic atrial fibrillation in a prospective, randomized, placebo-controlled study.

BACKGROUND

The effectiveness of amiodarone and propafenone in the treatment of patients with chronic atrial fibrillation has not been adequately studied.

METHODS

One hundred one patients (48 men, mean age 64 +/- 9 years) with atrial fibrillation lasting >3 weeks participated in the study. Thirty-four patients received amiodarone (300 mg intravenously over 1 h, followed by 20 mg/kg over the next 24 h plus 600 mg orally, in three doses, for 1 week, then 400 mg/day orally, for three weeks), 32 received propafenone (2 mg/kg intravenously over 15 min, followed by 10 mg/kg over 24 h and then 450 mg/day orally, for one month) and the remaining 35 served as control subjects. All patients received digoxin and anticoagulant treatment as indicated (International Normalized Ratio 2 to 3).

RESULTS

Conversion to sinus rhythm was achieved in 16 (47.05%) patients who received amiodarone, in 13 (40.62%) who received propafenone and in none of the control subjects (p < 0.001 for both groups vs. control subjects). Those who converted had smaller atria than those who did not and atrial fibrillation of shorter duration in both the amiodarone and propafenone groups. Treatment was discontinued in one patient of the propafenone group because of significant QRS widening.

CONCLUSIONS

Amiodarone and propafenone appear to be safe and equally effective in the termination of chronic atrial fibrillation. Left atrial diameter and arrhythmia duration are independent predictors of conversion.

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 propafenone administration--intravenous administration or short-term oral loading--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 (< or = 7 days' duration) admitted to the hospital without signs of organic heart disease (n = 42) or with systemic hypertension without signs or symptoms of heart failure (n = 45). The patients were assigned randomly to treatment with intravenous propafenone (29 patients), oral propafenone (29 patients), or placebo (29 patients).

INTERVENTIONS

Administration 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). Patients were submitted to Holter monitoring and conversion to sinus rhythm 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% with oral propafenone, and in 3% with placebo. At 3 h, the efficacy of intravenous propafenone (41%) and of oral propafenone (55%) were statistically superior to placebo (10% of conversions) and at 8 h either intravenous or oral propafenone were effective in almost two thirds of the patients with a statistical difference vs placebo, whose efficacy was 24%. No major side effects were observed.

CONCLUSIONS

Propafenone as an oral loading dose is an efficacious and fast way of treating atrial fibrillation of recent onset and due to its simplicity of administration and safety can be preferred to the intravenous route.

A controlled study on oral propafenone versus digoxin plus quinidine in converting recent onset atrial fibrillation to sinus rhythm

Eighty-seven patients with recent onset atrial fibrillation (< or = 8 days) without clinical signs of heart failure were randomly allocated to one of the following treatments: (i) oral propafenone (600 mg as a loading dose followed after 8 h by 300 mg t.i.d.); (ii) intravenous digoxin as acute scheme (up to 1.125 mg/24 h) followed after 6 h by hydroquinidine chlorhydrate (total dose, 1350 mg); or (iii) placebo. The patients were submitted to Holter monitoring for 48 h.

RESULTS

propafenone achieved higher successful conversion rates at 6, 12 and 24 h compared either with placebo (62% vs. 17%, 83% vs. 34%; 86% vs. 55%; P < 0.01, respectively) or with digoxin at 6 h (62% vs. 38%; P < 0.05) and digoxin plus quinidine at 12 h (83% vs. 48%; P < 0.05). At 48 h, a placebo conversion rate of 76% was observed with consequent lack of any significant difference with the active treatments. Mean conversion times within 48 h were 267 +/- 238 min for propafenone, 648 +/- 631 min for digoxin plus quinidine (P < 0.01 vs. propafenone) and 893 +/- 622 min for placebo (P < 0.001 vs. propafenone). Propafenone and digoxin plasma levels were within the therapeutic range. Asymptomatic phases of atrial flutter with > or = 2:1 atrio-ventricular conduction ratio were observed during Holter monitoring, before conversion to sinus rhythm, in four patients treated with propafenone, in one patient taking digoxin plus quinidine and in four patients with placebo.(ABSTRACT TRUNCATED AT 250 WORDS)