Electrocardiographic changes in normal adults following digitalis administration

[Digoxin induced changes in the exercise ECG and its relation to plasma concentrations (author's transl)]

The effects of a single intravenous dose (1.5 mg) of diogoxin on the resting and exercise ECG were studied over several days in twelve normal subjects. Maximal ST-segment and T-wave changes were observed 24 h after drug administration. A significant ST-segment depression and decrease in T-wave amplicude were still observed on the 7th and 11th day after the glycoside dose, in spite of undetectable digoxin plasma concentrations. There was no correlation between digoxin plasma concentration and ECG-changes. In order to avoid false positive ischaemic ST-segment responses to exercise, a therapy with digoxin should be discontinued for at least 2 weeks before the exercise test.

The effect of digitalis on the normal electrocardiogram

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The Nature of the RS-T Segment Displacement as Studied with Esophageal Leads

The electrocardiographic changes, with particular reference to the RS-T segment and T wave, in surface leads and in esophageal leads reflecting left ventricular cavity potentials, are studied in 7 persons with and without heart disease, before and after the administration of digitoxin. After the administration of digitoxin, the RS-T segment depression in precordial leads and in esophageal leads reflecting the potentials of the posterior surface of the left ventricle, are regularly associated with RS-T segment elevation in esophageal leads reflecting left ventricular cavity potentials. The possible roles played by myocardial involvement due to digitalis, modification of the monophasic curves, and the reduction of the human ventricular gradient are discussed.