The effect of large intravenous doses of sodium borate on the human myocardium as reflected in the electrocardiogram.

Abstract

Large intravenous doses of sodium borate, given to seven patients with brain tumors, caused development of temporary but consistent hypoxic-type abnormalities in the S-T segments and the T waves of the electrocardiogram. Correlation of these electrocardiographic changes with blood boron concentrations, determined up to 48 hours after boron injection, indicated that the changes were probably the result of damage by boron, present intracellularly in the myocardium. The intracellular concentrations which cause electrocardiographic abnormalities are considered to be of the order of 100 µg. per milliliter, similar to concentrations which have been shown to inhibit respiration in in vitro myocardial preparations.