Effectiveness of verapamil-quinidine versus digoxin-quinidine in the emergency department treatment of paroxysmal atrial fibrillation

Study objective: To determine the relative effectiveness of a verapamil-quinidine sequential combination versus digoxin-quinidine in the emergency department treatment of paroxysmal atrial fibrillation (PAF). Method: This prospective, double-blind, randomized, controlled trial involved patients, aged 18 to 75 years, with new-onset (<48 hours) atrial fibrillation who presented to a community-based urban hospital with an annual ED census of 65,000. Exclusion criteria included ventricular response rate lower than 1 DO or higher than 200 beats/minute, allergy to study drugs, hypotension with evidence of end-organ hypoperfusion, and conduction abnormalities. Consenting patients were randomly assigned to receive rapid digitalization (1.0 mg over 2 hours) or IV verapamil (sequential 5-mg boluses up to 20 mg). After ventricular rate was controlled (<100 beats/minute), oral quinidine (200 mg) was initiated and repeated every 2 hours until conversion to normal sinus rhythm (NSR) occurred, until 1 g of quinidine was administered, or until adverse effects supervened. Heart rate, blood pressure, cardiac rhythm, lime to conversion, and adverse effects were documented. Results: Forty-four patients received the study drugs. Three were withdrawn, leaving 19 in the verapamil-quinidine (VER-Q) group and 22 in the digoxin-quinidine (DIG-Q) group, Sixteen patients (84%) in the VER-Q group and 10(45%) in the DIG-Q group converted to NSR within 6 hours (P <.02). Mean time to conversion (+/-SD) was 185+/-146 minutes for VER-Q and 368+/-386 minutes for DIG-Q patients (FL-NS). Twelve VER-Q patients (63%) and 6 DIG-Q patients (27%) were discharged from the ED (P <.05). Minor adverse effects were more common in the VER-Q group. No mortality or significant morbidity occurred. Conclusion: The sequential combination of verapamil and quinidine, in the doses studied, is an effective treatment for PAF and is superior to digoxin-quinidine. Digoxin should no longer be considered the treatment of choice for uncomplicated PAF.