Evolution of stress testing.

Stress testing of patients with known or suspected coronary artery disease is an important part of patient management. The resting state frequently does not provide a complete evaluation, and the introduction of a stressful condition may be necessary to detect underlying or latent ischemia. The history of stress testing is long, varied, and highlighted by a series of technological advances in diagnostic methodology. The Master Two Step was probably one of the first clinically useful procedures for this purpose. With this test an electrocardiogram was obtained before and after a patient walked up and down two steps a given number of times. Despite the fact that the examination was helpful, there was an obvious need for improvement. By merely comparing the preexercise and postexercise electrocardiogram there were patients whose electrocardiographic abnormalities did not persist long enough to be detected. Furthermore, the type of exercise was limited and difficult to quantitate. Probably the first of the many major technological advances in stress testing was the development of an electrocardiographic system that produced high quality, interpretable tracings during exercise. This development was the breakthrough necessary for meaningful electrocardiographic monitoring of the exercising individual.