Electrocardiographic T-Wave Changes During Lithium Carbonate Treatment

Serial electrocardiograms were obtained under controlled and bouble-blind conditions before, during, and after lithium carbonate treatment in six manic-depressive patients. A statistically significant increase in the frequency of T-wave depression was observed to occur during lithium carbonate treatment in each patient, but no other ECG changes or serum electrolyte abnormalities were observed. The extent of T-wave depression was not related to sodium intake or to serum lithium ion levels. There was no evidence of cardiac damage as measured by normal serum enzyme studies and circulation times. Slight pretibial edema that occurred was not related to ECG T-wave changes. It is concluded that lithium carbonate treatment has a consistent, but benign and reversible, effect on the myocardium.