Atrial fibrillation: acute: clonidine reduced ventricular rate.

Clinical bottom line (level 2b)

  1. Patients with fast atrial fibrillation who received oral clonidine were more likely to have a fall in ventricular rate > 20% (NNT = 2 at 4 hours) , and more were likely to revert to sinus rhythm (NNT = 2 at 4 hours) .
Roth et al: Annals of Internal Medicine 1992; 116 (5): 388-390
Expires November 2003

The study

Unblinded ?concealed quasi-randomised trial without intention-to-treat
Setting: emergency department, university hospital, Israel

20 patients (aged mean 67 years, 56% male) rapid atrial fibrillation

Excluded if
  • haemodynamically unstable
  • acute or terminal illness
  • excessive hypertension
  • clinical evidence of thyrotoxicosis
  • pulmonary, valvular or pericardial disease
  • electrolyte imbalance
  • recent antiarrhythmic use


    • Control Group: (n = 10, 9 analysed): no intervention
    Experimental Group: (n = 10, 9 analysed): clonidine 0.075 mg po; with a further dose at 2 hours if no response

    90% followed for 4 hours

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    no reversion to sinus rhythm 4 hours 8
    (88.9%)    		 3
    (33.3%)    		 63%
    (3% to 86%)    		 55.6%
    (18.5% to 92.6%)    		 2
    (1 to 5)
    <20% fall in ventricular rate 4 hours 7
    (77.8%)    		 1
    (11.1%)    		 86%
    (6% to 98%)    		 66.7%
    (32.6% to 100%)    		 2
    (1 to 3)

    Comments

    1. Patients were allocated on an alternating basis to the two groups.
    2. Many patients revert spontaneously within 24 hours. These patients were cardiovascularly stable, so there was little urgency to slow the rate. A longer study may have shown less benefit.

    Citation

    1. Roth A, Kaluski E, Felner S, et al: Clonidine for patients with rapid atrial fibrillation. Annals of Internal Medicine 1992; 116 (5): 388-390
    Search Terms: atrial fibrill* in Cochrane
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer:

    Clinical Question.
    Patient AF
    Intervention or Exposure clonidine
    Comparison no intervention
    Outcome sinus rhythm