Postexercise electrocardiography: Correlations with coronary arteriography and left ventricular hemodynamics

The “2-step” exercise test provides an imperfect though independent means for predicting the presence and extent of significant coronary artery disease in the individual patient, and abnormal results on this test may suggest an associated abnormal rise in left ventricular filling pressure during exercise.

Abstract

Postexercise electrocardiograms were related to coronary arteriograms in 100 cases and were correlated with left ventricular hemodynamics at rest and during mild exercise in 78 of these cases. The incidence and degree of exercise-induced "ischemie" S-T segment depression increased significantly with increasing extent of coronary artery disease. A criterion for abnormality of 0.5 mm or greater S-T depression offered a specificity of true negative responses of 83 percent and a sensitivity of true positive responses of 63 percent. A criterion of 1.0 mm or greater S-T depression produced a specificity of 100 percent but at the expense of a reduced sensitivity of 35 percent true positive responses. Left ventricular end-diastolic pressure was the only hemodynamic index that correlated with either the extent of coronary artery disease or the degree of exercise-induced S-T segment depression. Patients with S-T segment depression of 1.0 mm or greater had significantly greater values for left ventricular end-diastolic pressure, both at rest and during exercise, than did patients with lesser degrees of S-T depression. The "2-step" exercise test provides an imperfect though independent means for predicting the presence and extent of significant coronary artery disease in the individual patient, and abnormal results on this test may suggest an associated abnormal rise in left ventricular filling pressure during exercise.