Efficacy of intravenous metoprolol in the treatment of atrial tachyarrhythmia

Objective To investigate the efficacy and safety of intravenous (IV) metoprolol in controling ventricular rate of atrial tachyarrhythmias. Methods Thirty atrial tachyarrhythmic patients with a ventricular rate 120 bpm were included and randomised to inject metoprolol or cedilanid. Blood pressures and heart rate were measured at base line (0min), before the second dosage, before the third dosage, 40, 60, 90, and 120 mins after injection . The effective criteria was defined as decreased ventricular rate 100 bpm or returning to sinus rhythm. Results Thirty patients (17 male, mean age 57.3±12.4 years), including 20 cases of atrial fibrillation, 5 cases of atrial flutter and 5 cases of atrial tachycardia,were randomised to metoprolol group or cedilanid group.The effective rate in the metoprolol group was significantly higher than that in the cedilanid group (53.3%, 86.7%, 93.3%, and 93.3% versus 13.3%, 20.0%, 40.0%, and 60.0%, respectively within 60 minutes. P0.05). The mean duration of achieving effectiveness for metoprolol and cedilanid was 12.6±6.7 mins and 53.0±28.4 mins, respectively (P0.01). The totally effective rate between two groups was not significantly different (93.3% in metoprolol group vs 80% in cedilanid group, P0.05). Conclusion Both metoprolol and cedilanid are effective and safe for the management of rapid ventricular rate in atrial tachyarrhythmia. However, the efficacy of ventricular rate control begins earlier with metoprolol than with cedilanid.