[Skip to Navigation]
November 1955

The Electrocardiogram in Electrolyte Imbalance

Author Affiliations


From the Philadelphia General Hospital and the Robinette Foundation and the Graduate School of Medicine of the University of Pennsylvania. Director, Division of Cardiology, Philadelphia General Hospital, and Division of Cardiovascular Disease, and Graduate Hospital of the University of Pennsylvania.

AMA Arch Intern Med. 1955;96(5):618-638. doi:10.1001/archinte.1955.00250160060005

The electrocardiogram is an extremely sensitive method of detecting certain types of electrolyte imbalance. The form of the normal electrocardiogram depends upon the normal ionic constitution of the cells and, particularly, of the extracellular fluid bathing the cardiac cells. Any significant alteration in the electrolyte content of this fluid, or in the ratio between them, may directly or indirectly produce significant electrocardiographic changes. The electrolytes which may produce the most profound effects of the electrocardiogram when they deviate from their normal levels are calcium and potassium.* Changes have also been reported following alterations in magnesium levels.7 A rise or fall of sodium content per se does not affect the electrocardiogram, but alterations in this electrolyte may indirectly change the potassium effect by inducing acidbase imbalance and by altering the potassiumto-sodium ratio.8 It should be remembered that the electrocardiogram reflects changes as they exist in the heart. Although these

Add or change institution