Atrial fibrillation: acute: verapamil and quinidine achieved cardioversion faster than digoxin and quinidine.

Clinical bottom line (level 1b)

  1. Patients with recent onset atrial fibrillation and a fast ventricular rate who received verapamil and quinidine compared with digoxin and quinidine were more likely to revert to sinus rhythm early (NNT = 3 at 6 hours) , but this difference was not clear at 24 hours.
  2. Patients given verapamil-quinidine were more likely to be discharged home (NNT = 3 at 6 hours) .
  3. There was no clear difference in the number of adverse events.
Innes et al: Annals of Emergency Medicine 1997; 29 (1): 126-134
Expires August 2003

The study

Double-blinded concealed randomised trial without intention-to-treat
Setting: emergency department, acute hospital, Canada.

44 patients (aged mean 60 years, 61% male) with atrial fibrillation of <48 hours and a ventricular rate >100 beats/ min

Excluded if
  • conduction abnormalities including second or third degree heart block, sick sinus syndrome, or QRS > 120 ms
  • hypotension (systolic blood pressure <90 mmHg) with evidence of end-organ hypoperfusion (confusion, comas, severe angina or acute MI)
  • allergy to digoxin, quinidine or verapamil
  • ventricular rate >200 beats/ min
  • aged <18 or >75


    • Control Group: (n = 25, 22 analysed): digoxin 500 µ g iv followed by two doses of 250 µ g if required. When the ventricular rate fell below 100 beats/ min, patients received quinidine 200 mg every two hours until cardioversion, adverse effects causing withdrawal or a total of 1 g was given
    Experimental Group: (n = 19, 19 analysed): verapamil 5 mg repeated up to a maximum of 20 mg in total. When the ventricular rate fell below 100 beats/ min, patients received quinidine 200 mg every two hours until cardioversion, adverse effects causing withdrawal or a total of 1 g was given.

    93% followed for 24 hours
    Outcome notes:
    • no cardioversion to sinus rhythm : at 6 hours
    • no cardioversion to sinus rhythm : at 24 hours
    • continued hospitalisation : if cardioversion occurred within 6 hours
    • adverse events : nausea, vomiting, bradycardia

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    no cardioversion to sinus rhythm 6 hours 12
    (54.6%)    		 3
    (15.8%)    		 71%
    (12% to 90%)    		 38.8%
    (12.3% to 65.3%)    		 3
    (2 to 8)
    no cardioversion to sinus rhythm 24 hours 6
    (27.3%)    		 2
    (10.5%)    		 61%
    (-69% to 91%)    		 16.8%
    (-6.42% to 39.9%)    		 6
    (NNT = 3 to infinity;
    NNH = 16 to infinity)
    continued hospitalisation 6 hours 16
    (72.7%)    		 7
    (36.8%)    		 49%
    (4% to 73%)    		 35.9%
    (7.31% to 64.5%)    		 3
    (2 to 14)
    adverse events 24 hours 2
    (9.09%)    		 3
    (15.8%)    		 -74%
    (-833% to 68%)    		 -6.70%
    (-27.0% to 13.6%)    		 -15
    (NNT = 7 to infinity;
    NNH = 4 to infinity)

    Comments

    1. There was no clear difference in the speed of control of ventricular rate.

    Citation

    1. Innes GD, Vertesi L, Dillon EC, et al: effectiveness of verapamil-quinidine versus digoxin-quinidine in the emergency department treatment of paroxysmal atrial fibrillation. Annals of Emergency Medicine 1997; 29 (1): 126-134
    Contributor: Chris Ball and Clare Wotton, August 1999
    Reviewer:

    Clinical Question.
    Patient acute atrial fibrillation and a fast ventricular rate-onset
    Intervention or Exposure verapamil and quinidine
    Comparison digoxin and quinidine
    Outcome conversion to sinus rhythm