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


METHODS
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 100 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 i.v. 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, time 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 Three were withdrawn, leaving 19 in the verapamil-quinidine (VER-Q) group and 22 in the digoxin-quinidine (DIG-Q) group.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 (P = 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.


CONCLUSIONS
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.
Innes
G D
GD
Department of Emergency Medicine, Royal Columbian Hospital, New Westminster, British Columbia, Canada.
Vertesi
L
L
Dillon
E C
EC
Metcalfe
C
C
D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use*; D001281:Atrial Fibrillation / Q000188:drug therapy*; D004077:Digoxin / Q000627:therapeutic use*; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D004632:Emergency Medical Services / Q000379:methods*; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011802:Quinidine / Q000627:therapeutic use*; D013614:Tachycardia, Paroxysmal / Q000188:drug therapy*; D016896:Treatment Outcome; D014700:Verapamil / Q000627:therapeutic use*
D000889:Anti-Arrhythmia Agents; D004077:Digoxin; D014700:Verapamil; D011802:Quinidine