Abstract
Treadmill stress tests were reviewed retrospectively in 59 patients; 25 without coronary artery disease (normal group) and 34 with coronary artery disease. Changes in the sum of the amplitude of R waves and RS waves in leads CM 5, CC 5 and CL were measured both during the control period and immediately following the exercise period.
Of 25 patients without coronary artery disease, R wave amplitude increased in 23 (92%) and decreased in 2(8%) patients. On the other hand, of 34 patients with coronary artery disease, R wave amplitude decreased in 27(79%) and had either no change or increased in 7 (21%) patients. When there were either no changes or an increase in R wave amplitude after exercise, this was defined as“R wave criteria”.
There were no significant differences between normal group and coronary artery disease group in R wave amplitude changes, and there was also no significant correlation between resting left ventricular performance and“ST-segment criteria”(ST-segment depression>0.05mV) or “R wave criteria” in the latter group.
According to the “ST-segment criteria”, 4(16%) patients without coronary artery disease and 26 (76%) patients with coronary artery disease showed positive, and 8 (24%) patients showed false negative results.
The sensitivity and the specificity of “ST-segment criteria” were 76% and 84%, respectively, whereas those of “R wave criteria” were 21% and 92%, respectively.
Thus, “ST-segment criteria” was much more useful than “R wave criteria” in the diagnosis of coronary artery disease.
