POTASSIUM AND THE CARDIOGRAPHIC CHANGES IN DIABETIC ACIDOSIS

Abstract

This investigation was attempted in order to evaluate the cardiogram as a guide in estimating the level of potassium in the serum during, and when a patient is emerging from, diabetic acidosis.Shirley Smith and Hickling (1932) in a paper on cardiographic abnormalities in severe diabetes concluded that these changes represented mainly parenchymatous damage to the heart resulting from defective nutrition and that coronary disease, whether permanent or reversible, probably played a subsidiary role.Cardiographic changes in diabetic acidosis were described by Bellet and Dyer (1937) in a study of seventeen cases of coma and six of precoma; they listed lengthening of the Q-T interval, depression of the S-T segment, and inversion of the T wave as the most frequent findings and alteration of the QRS complex as infrequent.Other changes since described are: slight alteration in the character and amplitude of the P wave (Martin and Wertman, 1947); a prominent U wave (Ernstene and Proudfit, 1949); and cardiac arrhythmias (Bellet et al., 1950).Ernstene and Proudfit (1949) did not find any constant lengthening of the Q-T interval in the cases they studied and pointed out that the commonly present U wave may cause apparent lengthening of the Q-T interval by partial fusion with the descending limb of the T wave.The cause or causes of the cardiographic changes have been the subject of controversy among many authors.Because of the rapid development and regression of the abnormalities, Bellet and Dyer (1937) suggested that they were the result of a transient electrolyte imbalance.In the series of Martin and Wertman (1947) no close correlation was found between the levels of serum potassium and the depression of the S-T segment and prolongation of the Q-T interval.They thought that very low T waves were associated with low levels of serum potassium.Tarail (1948) found that the changes in the cardiograms of three out of five patients did not correlate with the degree of hypopotassemia.Bellet et al. (1950) concluded that " The Q-T interval was a crude guide to the degree of hypopotassaemia, although the T wave and S-T changes were not reliable criteria of the degree of hypopotassemia when comparisons were made in different patients; on the same patient, however, they correlated fairly well with the degree of hypopotassemia."Cardiographic changes similar to those found in dabetic acidosis, and associated with disturb- ances of potassium metabolism have provided further material for controversy concerning the role of serum potassium in their production.Steward et al. (1940), Stoll and Ninsnewitz (1941), and Perelson and Cosby (1949) described the cardiographic findings during the paralytic and recovery phases of familial periodic paralysis.Ermstene and Proudfit (1949) recorded the levels of potassium in the serum in a patient with Addison's disease who developed invertion of T waves, depression of S-T segments, and prominent U waves after being treated with desoxycorticosterone acetate to excess.Perkins et al. (1950) reported cardiographic findings in one case and McAllen (1951) in three of chronic diarrhoea with hypopotassemia.The former described lengthening of the Q-T interval while the latter thought there was little if any Q-T change.Both of these authors con- cluded that there was correlation between the T wave and the S-T changes and the degree of hypo- 87on August 21, 2023 by guest.