Effects of Cortisone on Electrocardiographic Changes in Adrenal Insufficiency. ∗

Abstract

Discussion and Conclusions

The changes in the electrocardiogram in adrenal insufficiency were found to parallel the alterations in plasma sodium and potassium; these were prevented with adequate maintenance dosages of cortisone but not corrected completely by this steroid after marked abnormalities in the electrocardiogram had occurred. This is in keeping with the concept ( 2 , 6 ) that the defects in cardiac function, found in adrenal insufficiency are the result of losses of body sodium and elevation of plasma potassium with a consequent imbalance of these ions. If this were the cause, it would be expected that abnormalities of the electrocardiogram would be reversed toward normal only by restoration or maintenance of adequate concentrations of sodium and potassium; such was found to be the case in our experiments.

It is currently taught that the difference in potential which exists across the cell membrane is dependent, in part, upon the difference in concentration of potassium between the intra- and extracellular compartments. Alterations in this concentration, as are seen in conditions of hyperkalemia, result in a variety of disturbances in neuro-muscular activity and, more particularly, myocardial function ( 9 , 11 , 12 ), which result in such clinically overt findings as described above.

In adrenal insufficiency it has been repeatedly observed( 4 , 5 , 7 ), that sodium chloride administration in adequate amounts will lower plasma potassium concentration and restore the electrocardiographic abnormalities toward normal; from this it would appear that these disturbances are directly related to abnormalities in sodium and potassium metabolism and are reversible only if adequate concentrations of these ions are restored.

Since cortisone has been found to correct the renal functional defect on sodium excretion and to maintain normal plasma concentrations of sodium and potassium, it is conceivable that the disturbances in the electrocardiogram seen in adrenal insufficiency are effected by this steroid only in so far as it corrects the abnormalities in electrolyte metabolism.