Magnesium Sulfate and Chloride in Suppression of Ectopic Ventricular Tachycardia Accompanying Acute Myocardial Infarction

Abstract

MgSO4 and MgCl2 were useful in the control of this arrhythmia in 36 dogs. Injection of 1 meq./kg. of either salt within a 10-min. period resulted in diminutions in mean blood pressure of 5 to 30 mm. Hg. Recovery to the control pressure level following the greater drops required about 30 min. Vomiting due to Mg in injn. was prevented by morphine. Mortality due to Mg was not increased by morphine but was markedly increased by strong sedation (2/3 anesthetic doses) with pentobarbital Na or barbital Na. The results of the tests with the 2 Mg salts considered as one series were found to approximate the results obtained in earlier expts. with intraven. quinidine compounds, using similar signs to guide dosage. The mechanism of ectopic impulse suppressor effect is briefly discussed in relation to known effects of Mg and Ca salts upon ATP-ATP-ase reactions.