Intravenous Magnesium Sulfate Enhances the Ability of Intravenous Ibutilide to Successfully Convert Atrial Fibrillation or Flutter

Abstract

Concurrent use of magnesium enhanced the ability of ibutilide to successfully convert atrial fibrillation (AF) or flutter (AFl). The 4 grams magnesium dose appeared to provide the greatest benefit.

Magnesium for Atrial Fibrillation, Myth or Magic?

“…Although there are data to support the use of magnesium for facilitating pharmacological cardioversion, this is largely based on retrospective analyses in patients receiving ibutilide or dofetilide as antiarrhythmic drug therapy. [16][17][18] Magnesium has also been noted as a potential drug for complementing a rate control approach. In meta-analysis of 5 randomized trials (n=380), patients receiving magnesium were 3× as likely to reach a heart rate <100 beats per minute compared with placebo, mostly with digoxin as background therapy.…”

Intraoperative Magnesium Administration Does Not Reduce Postoperative Atrial Fibrillation After Cardiac Surgery

“…24,25 Consistent with these electrophysiologic actions, Mg administration has been shown in several clinical studies to significantly improve the rate of chemical [26][27][28] and electrical cardioversion 29 of atrial arrhythmias. Investigations of Mg prophylaxis for the prevention of POAF in the context of cardiac surgery appeared to confirm these beneficial results.…”

Efficacy of Intravenous Magnesium in Facilitating Cardioversion of Atrial Fibrillation

“…Previous studies have shown a benefit of Mg in patients with AF by increasing the success of pharmacological cardioversion and by decreasing the incidence of postoperative AF. 8,9,22,23 Facilitation of cardioversion by Mg has been studied more commonly in pharmacological cardioversion, in which Mg also has the benefit of decreasing adverse events, such as torsades de pointes. 8,9 However, there is a paucity of data on the role of Mg alone in facilitating electric cardioversion.…”

“…Because the study involved a bolus administration of MgSO 4 , a dose of 2 g was chosen, as it was readily available in most hospitals and was the bolus dose used in many trials. 8,10,11 MgSO 4 (Hospira, Inc) 2 g vials were reconstituted with normal saline into a 50-mL infusion, which was administered over 30 minutes through a peripheral intravenous line. A 50 mL infusion of normal saline was used as the placebo.…”