CLINICAL-SIGNIFICANCE OF SIMPLE HEART RATE-ADJUSTED ST SEGMENT DEPRESSION IN SUPINE LEG EXERCISE IN THE DIAGNOSIS OF CORONARY-ARTERY DISEASE

To evaluate the clinical significance of simple heart rate-adjusted ST segment depression ( ΔST ΔHR) in the diagnosis of coronary artery disease, 42 patients with stable exertional angina underwent supine leg exercise testing and cardiac catheterization. During exercise, heart rate, a multilead electrocardiogram, and pulmonary artery wedge pressure were recorded. The sensitivity and accuracy of the ΔST ΔHR criteria (≥3.0 μV/beat/min) were significantly greater than the conventional analysis of ST segment depression criteria (≥0.2 mV) for detecting three-vessel coronary artery disease at a matched specificity of 72% (100% versus 46%, 81% versus 64%, p < 0.01). A significant linear correlation was found between maximum pulmonary artery wedge pressure increments during exercise (ΔPAWP) or Gensini score and the ΔST ΔHR (ΔPAWP: r = 0.51, p < 0.001; Gensini score: r = 0.47, p < 0.001). There were no statistically significant differences in the ΔPAWP or Gensini score between patients with three-vessel disease who had ΔST ΔHR ≥ 3.0 μV/beat/min and those with one- or two-vessel disease who had ΔST ΔHR ≥ 3.0 μV/beat/min (ΔPAWP: 18.1 ± 2.0 versus 21.9 ± 3.3, p = NS; Gensini score: 68.5 ± 6.6 versus 66.3 ± 11.3, p = NS). These findings demonstrate that ΔST ΔHR is more useful than a conventional analysis of ST segment depression for identifying not only anatomically severe coronary artery disease but also functionally severe coronary artery disease. © 1990.