Can magnesium sulfate be used for stable ventricular tachycardia (V-tach)?

From the Guidelines

Magnesium sulfate is not typically recommended as a first-line treatment for stable ventricular tachycardia (V-tach), but it may be considered in specific situations, particularly when V-tach is associated with torsades de pointes or in patients with hypomagnesemia, as supported by the 2018 guidelines 1. The standard treatments for stable V-tach include antiarrhythmic medications such as amiodarone (150 mg IV over 10 minutes, followed by 1 mg/min infusion for 6 hours, then 0.5 mg/min) or procainamide (20-50 mg/min IV until arrhythmia suppressed, hypotension occurs, QRS widens by >50%, or maximum dose of 17 mg/kg reached).

• Magnesium sulfate may be used in cases of torsades de pointes, with a typical dose of 1-2 grams IV given over 5-20 minutes, as recommended by the 2010 American Heart Association guidelines 1.
• The use of magnesium sulfate in stable V-tach is supported by its ability to stabilize cardiac cell membranes and influence calcium channels, which can help terminate certain types of ventricular arrhythmias, as noted in the 2006 ACC/AHA/ESC guidelines 1.
• It is essential to monitor for side effects such as flushing, hypotension, and respiratory depression, especially with rapid administration, and to maintain blood pressure and cardiac monitoring throughout treatment, with calcium gluconate available as an antidote in case of magnesium toxicity, as advised in the 2010 guidelines 1.
• The 2018 guidelines 1 provide the most recent and highest-quality evidence, prioritizing the use of magnesium sulfate in specific situations, such as torsades de pointes, while emphasizing the importance of standard treatments for stable V-tach.

From the Research

Magnesium Sulfate for Stable Ventricular Tachycardia (V-tach)

• Magnesium sulfate has been studied as a potential treatment for various ventricular arrhythmias, including stable ventricular tachycardia (V-tach) 2, 3, 4, 5.
• The effectiveness of magnesium sulfate in treating V-tach is controversial, with some studies showing positive results 3, 4, 5 and others showing limited efficacy 2.
• In patients with torsade de pointes tachycardia, magnesium sulfate has been shown to be highly effective in controlling the arrhythmia 2, 5.
• For patients with persistent monomorphic ventricular tachycardia, the results are less clear, with some studies suggesting that magnesium sulfate may be effective in a minority of patients 2, 3.
• The optimal dosage and administration of magnesium sulfate for V-tach is not well established, but typical dosages range from 2-4 grams intravenously, followed by continuous infusion 4, 5.

Key Findings

• A study published in 1997 found that magnesium sulfate controlled ventricular tachycardia in 8 of 25 patients with persistent monomorphic V-tach, but the difference was not statistically significant compared to placebo 2.
• A 1987 study reported that magnesium sulfate infusion was effective in treating various ventricular arrhythmias, including torsade de pointes and polymorphic ventricular ectopic beats 3.
• A 1983 study found that magnesium sulfate was effective in treating intractable ventricular tachyarrhythmias in normomagnesemic patients 4.
• A 1988 study demonstrated that magnesium sulfate was highly effective in treating torsade de pointes, with a response rate of 100% in 12 consecutive patients 5.