Atrial fibrillation: diltiazem slowed the ventricular rate.

Clinical bottom line (level 1b)

  1. Patients with fast atrial fibrillation or flutter who were given diltiazem were more likely to have there ventricular rate decreased than those given placebo (NNT = 1 at 30 minutes) .
  2. Heart rate slowed by around 20 beats per minute.
Salerno et al: American Journal of Cardiology 1989; 63: 1046-1051
Expires November 2004

The study

Double-blinded concealed randomised trial with intention-to-treat
Setting: six acute hospitals, USA

113 patients (aged mean 64 years, 73% male) spontaneous atrial fibrillation and flutter (>120 beats per minute for 15 minutes)

Excluded if
  • <18 years old
  • childbearing potential
  • congestive heart failure (NYHA III or IV)
  • known sick sinus syndrome, 2nd or 3rd degree heart block
  • pre-excitation syndromes, atrial tachycardia
  • hypotension with systolic bp < 90 mmHg, cardiogenic or septic shock
  • myocardial infarct within one month
  • history of allergy to diltiazem
  • clinically significant abnormalities of other organs or metabolites
  • any calcium antagonists and flecainide taken for 5 half-lives


    • Control Group: (n = 57, 56 analysed): placebo
    Experimental Group: (n = 56, 56 analysed): diltiazem 0.25 mg/kg over 2 minutes, followed 15 minutes later by 0.35 mg/kg over 2 minutes if no response

    100% followed for 30 minutes
    Outcome notes:
    • failure : success: ventricular rate < 100 bpm or persistent AF with > or = 20% decrease in ventricular rate and rate > 100 bpm

    The evidence

    Outcome Time to outcome CEREERRRR
    (95% CI)    		ARR
    (95% CI)    		NNT
    (95% CI)
    failure 30 minutes 50
    (87.7%)    		 4
    (7.14%)    		 92%
    (79% to 97%)    		 80.6%
    (69.7% to 91.4%)    		 1
    (1 to 1)

    Outcome Control Group
    (SD)    		 Experimental Group
    (SD)    		 Mean Difference
    (95% CI)
    heart rate (beats/min) at 0 minutes 139
    (12)     		145
    (19)     		6
    (0 to 12)
    heart rate (beats/min) at 30 minutes 140
    (20)     		119
    (19)     		-21
    (-28 to -14)

    Comments

    1. How does this compare with digoxin?

    Citation

    1. Salerno DM, Dias VC, Kleiger RE, et al: Efficacy and safety of intravenous diltiazem for treatment of atrial fibrillation and flutter. American Journal of Cardiology 1989; 63: 1046-1051
    Contributor: Chris Ball and Clare Wotton, November 2000
    Reviewer:

    Clinical Question.
    Patient AF or flutter
    Intervention or Exposure diltiazem
    Comparison placebo
    Outcome decrease in ventricular rate