Conversion of atrial fibrillation to sinus rhythm and rate control by digoxin in comparison to placebo

Area of Science:

• Cardiology
• Pharmacology

Background:

• Atrial fibrillation is a common arrhythmia requiring effective treatment for rhythm and rate control.
• Intravenous digoxin is used for rate control and sometimes for rhythm conversion in atrial fibrillation.

Purpose of the Study:

• To evaluate the efficacy of high-dose intravenous digoxin for conversion to sinus rhythm and for rate control in patients with recent-onset atrial fibrillation.
• To compare digoxin's effectiveness against placebo in a randomized, double-blind study.

Main Methods:

• A randomized, double-blind study involving 40 patients with recent-onset atrial fibrillation (< 1 week).
• Patients received either intravenous digoxin (1.25 mg) or intravenous saline (placebo).
• Outcomes included conversion to sinus rhythm within 12 hours, time to conversion, and early/stable rate control.

Main Results:

• Conversion rates were similar between digoxin (9/19) and placebo (8/20) groups (not significant).
• Digoxin showed a trend towards shorter conversion time but provided only weak rate control, with persistent slowing in only 3/10 non-converters.
• Adverse events included bradyarrhythmias in two patients; QTc interval was shortened post-conversion.

Conclusions:

• Intravenous digoxin does not offer significant advantages over placebo for converting recent-onset atrial fibrillation to sinus rhythm.
• Digoxin provides weak rate control in this clinical setting.
• Further research may be needed to clarify digoxin's role in specific atrial fibrillation scenarios.