Recording the Electrocardiogram during the Performance of the Master Two-Step Test: II

Abstract
Recording the 2-step test during its performance is technically feasible and represents a useful addition to the post-exercise procedure. Radiotelemetry is not required for this purpose, since the ecg can be recorded with the patient connected to the electro-cardiography by means of a patient cable. An abnormal response to exercise in subjects with ischemic heart disease was observed more often in the post-exercise record than in the monitored tracing. This is most likely due to the fact that in the former, at least four different leads are recorded, while only one is employed in the latter technique. It is also possible that some individuals with only mild disease may compensate coronary flow during stress, and only manifest "oxygen debt" in the post-exercise period. The incidence of false positive responses is not increased by the monitored procedure. Criteria employed by the authors for interpreting the post-exercise record appear to be valid in the interpretation of the monitored tracing. It is suggested that after the conclusion of each monitored procedure, conventional leads 11, V4, V5, V6 be taken immediately, 2 minutes and 6 minutes after exercise as originally recommended by Master.