Comparing Magnesium 2g Versus 4g Versus Placebo in the Incidence of Treating AFF RVR

Intravenous magnesium has become a commonly utilized agent in the treatment of cardiac arrhythmias as an adjunct therapy to rate and rhythm control medications, such as its use in atrial fibrillation or atrial flutter with rapid ventricular response (AFF RVR). Though its benefit in the treatment of AFF RVR has been well documented, a consensus on the optimal dosing of magnesium has yet to be achieved. Only one randomized, controlled, double-blinded study has investigated the optimal dosing of magnesium.

Inclusion criteria

• Age > 18 years or older
• Able to provide informed consent
• Primary diagnosis AFF RVR greater than or equal to 120 bpm
• Diltiazem as rate control agent
• English speaking

Exclusion criteria

• Hemodynamically unstable patients (SBP <90, MAP <65)
• Impaired consciousness
• End stage renal disease on hemodialysis or peritoneal dialysis
• Acute heart failure exacerbation based on clinical diagnosis, physician exam, bedside echo, and/or additional imaging
• Patient in AFF RVR that is highly suspected to be a compensatory mechanism for an alternative clinical diagnosis
• Rhythms other than AF, such as sick sinus syndrome or wide-complex ventricular response
• Acute myocardial infarction
• Pregnancy defined as a positive urine HCG (human chorionic gonadotropin)
• Contraindications to magnesium sulfate (including myasthenia gravis)
• Allergy or sensitivity to any study drugs
• Previously enrolled in this trial during a different patient encounter
• Withdrew from study