Beschreibung:
<jats:title>Abstract</jats:title><jats:p><jats:bold>Objectives: </jats:bold> The objective was to investigate the efficacy of magnesium sulfate (MgSO<jats:sub>4</jats:sub>) in decreasing the ventricular rate in emergency department (ED) patients presenting with new‐onset, rapid atrial fibrillation (AF).</jats:p><jats:p><jats:bold>Methods: </jats:bold> A double‐blinded, placebo‐controlled randomized clinical trial was conducted in an adult university hospital. Patients aged ≥18 years with AF onset of less than 48 hours and a sustained ventricular rate of >100 beats/min were randomized to either intravenous (IV) MgSO<jats:sub>4</jats:sub> 10 mmol or normal saline (NSal). Rhythm and instantaneous heart rate as measured by the monitor were recorded at baseline and every 15 minutes for 2 hours after starting the trial drug. Heart rate and rhythm were compared at 2 hours. A multilevel modeling analysis was performed to adjust for differences in baseline heart rate and any additional treatment and to examine changes in heart rate over time.</jats:p><jats:p><jats:bold>Results: </jats:bold> Twenty‐four patients were randomized to MgSO<jats:sub>4</jats:sub> and 24 to NSal. Baseline heart rate was lower in the MgSO<jats:sub>4</jats:sub> group (mean ± standard deviation [±SD] = 125 ± 24 vs. 140 ± 21 beats/min]. One and 3 patients in the MgSO<jats:sub>4</jats:sub> and NSal groups, respectively, were given another antiarrhythmic or were electrically cardioverted within 2 hours after starting the trial drug. Heart rate (mean ± SD) at 2 hours in both MgSO<jats:sub>4</jats:sub> (116 ± 30 beats/min) and NSal groups (114 ± 31 beats/min) decreased below their respective baseline levels. However, the rate of heart rate decrease across time did not differ between groups (p<jats:italic> = </jats:italic>0.124). The proportion of patients who converted to sinus rhythm 2 hours post–trial drug did not differ (MgSO<jats:sub>4</jats:sub> 8.7% vs. NSal 25.0%, p<jats:italic> = </jats:italic>0.25).</jats:p><jats:p><jats:bold>Conclusions: </jats:bold> This study was unable to demonstrate a difference between IV MgSO<jats:sub>4</jats:sub> 10 mmol and saline placebo for reducing heart rate or conversion to sinus rhythm at 2 hours posttreatment in ED patients with AF of less than 48 hours duration.</jats:p>