M.: Recording the electrocardiogram during the performance of the Master two-step test

THE resting electrocardiogram is normal or "borderline " in at least 50 per cent of patients with ischemic heart disease and an-gina pectoris. ' In the great majority of such cases, however, tracings taken after exercise manifest diagnostic changes. A widely em-ployed, standardized method of eliciting such electrocardiographic abnormalities is the Mas-ter two-step test,2 3 whose value in the diag-nosis of ischemic heart disease is established. The development of electronic devJices that permit the radio transmission of electrophysio-logic data from a distance i has stimulated interest in monitoring the two-step test during its actual performance. One technic for doing so with the patient remaining attached to the electrocardiograph machine has also been de-scribed.'; Since 1961, we have been evaluating several methods for recording the electrocardiogram during exercise. It is the purpose of this paper to report some of the theoretical and prac-tical problems encountered in radioelectro-cardiography, and to describe a simple, inex-pensive technic for recording the electrocardi-ogram during the two-step test, with only conventional electrocardiographic equipment. Methods Differenit monitoring technics, types of equip-ment, electrodes, pastes, and electrode positioIns were employed in 80 healthy medical and nursin