ABNORMAL ELECTROCARDIOGRAMS IN RATS FED A LOW SELENIUM DIET

Abstract

Electrocardiograms of rats maintained on selenium‐low diets show the early development of a characteristic abnormality. The change in the ECG pattern becomes very marked as death approaches, although animals probably do not die directly of heart failure. Histological changes seen in the cardiac muscle of these animals suggests that the abnormal ECG pattern is related to a change in the properties of the muscle fibres rather than the electrolyte disturbances, or other changes in plasma constituents. Plasma electrolyte determinations in these rats developing abnormal ECG's included Na, K, Ca, and Mg; all values were within normal limits as compared with animals receiving the same diet though supplemented with selenium, in which abnormal ECG's did not occur. Evidence is also presented that blood glucose levels cannot explain the ECG abnormalities.