Effects of Digitalis Upon Body Electrolytes

Studies of the electrolyte alterations in 54 dogs during 165 discrete digitalizations with acetyl strophantbidin to an endpoint of ventricular tachycardia are reported. In 94 per cent of digitalizatious, increase in arterial potassium concentration occurred. This was noted as early as five niinutes after drug administration. At the time of ventricular tachycardia, the increase was 0.67 mEq./L. When digitalization was carried to ventricular fibrillation, the increase was 3.1 mEq./L. In 75.5 per cent of the digitalizations, arterial sodium concentration decreased; average de crease was 2.6 mEq./L. At ventricular fibril lation, the decrease amounted to 11.0 mEq./L. Arterial calcium concentration and oxygen saturation were not altered. There was a modest decrease in CO2 content and an increase in arterial pH and hcmatoerit. Peaking of the late portion of the T wave was common during acute digitalization and correlated with the increase in extracellular potassium concentration. The relationship of the electrolyte changes to the process of digitalization is discussed.