Comparison of the Effectiveness of Intravenous Diltiazem and Metoprolol in the Management of Rapid Ventricular Rate in Atrial Fibrillation

Objective: To compare the effectiveness of intravenous (IV) diltiazem and metoprolol in the management of rapid ventricular rate in atrial fibrillation (AF).

Methods: This prospective, randomised study was conducted in the Emergency Department of the Uludag University Medical Faculty Hospital, Bursa, Turkey. Forty AF patients with a ventricular rate > or = 120/minute and systolic blood pressure > or = 95 mm Hg were included and randomised to receive IV diltiazem 0.25 mg/kg (maximum 25 mg) or metoprolol 0.15 mg/kg (maximum 10 mg) over 2 minutes. Blood pressures and heart rate were measured at 2, 5, 10, 15, and 20 minutes. Successful treatment was defined as fall in ventricular rate to below 100/minute or decrease in ventricular rate by 20% or return to sinus rhythm.

Results: Between January 2000 and July 2002, 40 patients (18 men, 22 women) met the inclusion criteria. Of these 20 (8 men, 12 women; mean age 60.2 years, range 31-82) received diltiazem and 20 (10 men, 10 women; mean age 64.0 years, range 31-82) received metoprolol. The success rate at 20 minutes for diltiazem and metoprolol was 90% (n = 18) and 80% (n = 16), respectively. The success rate at 2 minutes was higher in the diltiazem group. The percentage decrease in ventricular rate was higher in the diltiazem group at each time interval. None of the patients had hypotension.

Conclusion: Both diltiazem and metoprolol were safe and effective for the management of rapid ventricular rate in AF. However, the rate control effect began earlier and the percentage decrease in ventricular rate was higher with diltiazem than with metoprolol.