Electrocardiographic Manifestations of Hypocalcemia Produced With Ethylenediamine Tetraacetic Acid

Abstract

Electrocardiographic changes associated with the hypocalcemic state induced in rabbits by the rapid intravenous injection of the disodium salt of ethylenediamine tetraacetic acid (EDTA) were studied. The rate of administration was varied between 50 and 120 seconds; more electrocardiographic abnormalities were produced when the EDTA was administered in less than 50 seconds. The most frequent finding was a prolonged Q-T interval caused predominantly by a lengthening of the ST segment. Abnormal T waves were observed in a significant number of animals. Electrical alternans of the T wave, not reported in association with clinical hypocalcemia, was also found. The exact mechanism responsible for the electrical alternans associated with EDTA is unknown.