Author + information
- Received September 24, 1982
- Revision received January 24, 1983
- Accepted February 9, 1983
- Published online July 1, 1983.
- Jay Colby, BS,
- A-Hamid Hakki, MD, FACC,
- Abdulmassih S. Iskandrian, MD, FACC* and
- Steven Mattleman, MD
- ↵*Address for reprints: Abdulmassih S. Iskandrian, MD, Hahnemann University, 230 North Broad Street, Philadelphia, Pennsylvania 19102.
The results of treadmill exercise electrocardiograms were analyzed in 179 patients with coronary artery disease ( ≥ 50% diameter narrowing of one or more vessels). Exercise thallium-201 images were available in 141 of these patients. The exercise electrocardiograms were strongly positive in 51 patients, mildly positive (1 to 1.9 mm ST depression) in 28 patients, falsely negative in 23 patients and uninterpretable in 77 patients.
The degree of exercise-induced ST depression did not correlate with left ventricular function, extent of coronary artery disease, exercise heart rates and rate-pressure product and extent of exercise-induced thallium-201 perfusion abnormality. However, the presence of a strongly positive exercise electrocardiogram only at heart rates of 140 beats/min or more or stage III or higher of the Bruce protocol was predictive of less extensive coronary disease and perfusion abnormalities.
Thus, the magnitude of ST depression as such during exercise is not predictive of the extent of coronary disease, even in patients with 3 mm or greater ST depression. However, a strongly positive exercise electrocardiogram in the first two stages of the Bruce protocol or at a heart rate of less than 140 beats/min was related to the extent of coronary artery disease and impaired myocardial perfusion, and identified patients with more extensive coronary artery disease and jeopardized myocardium. Therefore, caution should be used in interpreting prognostic data on the basis of the degree of exercise-induced ST depression alone.
- Received September 24, 1982.
- Revision received January 24, 1983.
- Accepted February 9, 1983.
- American College of Cardiology Foundation