For a thorough understanding of the action of the heart, it is important that it be studied under various conditions of stress. This investigation was undertaken to determine whether there are any abnormalities in the mechanism of the heart beat, demonstrable by electrocardiography, during the period of anesthetization and surgical operation.
Heard and Strauss1 reported a case of atrioventricular rhythm detected electrocardiographically in a patient still under ether following an operation. They state, "no other cases of nodal rhythm have been observed by us in a series of twenty-one cases in which electrocardiographic records have been taken during anesthesia." Levine2 reported cases of acute cardiac upsets occurring in association with surgical operations. In two of his cases electrocardiographic tracings were made during attacks of paroxysmal auricular tachycardia while the patients were still under ether. These two reports were the only references to the subject found in the literature.
LENNOX WG, GRAVES RC, LEVINE SA. AN ELECTROCARDIOGRAPHIC STUDY OF FIFTY PATIENTS DURING OPERATION. Arch Intern Med (Chic). 1922;30(1):57-72. doi:10.1001/archinte.1922.00110070060004