A Clinical and Experimental Study of the Electrocardiographic Changes in Extreme Acidosis and Cardiac Arrest

This investigation of the electrocardiographic and biochemical changes in very severe acidosis was prompted by the study of a patient with cardiac arrest (Stewart, Stewart, and Gillies, 1962) in whom improvement of myocardial activity appeared to be correlated with correction of acidosis. This paper describes clinical and experimental data indicating that heart block and asystole may be caused by metabolic acidosis and supporting the view (Stewart, 1964) that acidosis may sometimes prevent restoration of cardiac function. Acid-base measurements and electrocardio- grams were obtained when practicable in clinical cases of cardiac arrest and in the experimental animals metabolic acidosis was induced by infusion of 03 M HCl. We believe that these studies have important practical applications in the clinical management of patients especially where electrocardiographic monitoring is used in conjunction with external cardiac massage.