Comparison of the ST/heart rate slope with the modified Bruce exercise test in the detection of coronary artery disease.

The rate of depression of the ST segment with increasing heart rate (HR) during exercise has been claimed to predict the extent of coronary artery disease (CAD). To determine whether the maximal ST/HR slope is better than the Bruce treadmill exercise test for predicting the presence of CAD, the maximal ST segment/HR slope was calculated in 81 patients and compared with the results of a standard 12-lead exercise test. In 21 patients (26%), the ST/HR slope could not be calculated. In 60 patients with ST/HR slope values, the extent of CAD was predicted in 24 patients (40%). The sensitivity and specificity of the ST/HR slope in predicting the presence of CAD in the 60 patients with slope values were 91% and 27%, respectively. The sensitivity and specificity of the modified Bruce treadmill exercise test in the 81 patients were 81% and 64%, respectively. Thus, the use of the ST/HR slope does not provide additional information that cannot be obtained using the standard Bruce exercise test.