Evaluation of R wave amplitude changes versus ST-segment depression in stress testing.

TLDR

The study aimed to determine whether R‑wave amplitude changes could significantly improve the sensitivity and specificity of exercise stress testing. The authors reviewed exercise ECGs and coronary angiograms from 266 patients, selected false‑positive and false‑negative ST responses, and measured pre‑ and post‑exercise R‑wave amplitude changes, interpreting increases or no change as abnormal and decreases as normal. R‑wave criteria raised sensitivity from 48 % to 63 % and specificity from 59 % to 79 %, significantly improving stress‑testing accuracy.

Abstract

Exercise ECGs and coronary angiograms were reviewed in 266 patients (81 normals and 185 with significant coronary artery disease). Thirty-three false positive and 96 false negative ST responses to stress testing were purposely chosen to determine if the R wave could reduce the number of false ST responses. R wave amplitude changes were measured in the control and in the immediate postexercise period. An increase or no change in R wave was taken as evidence of an abnormal response, while a decrease in the R wave was a normal response. The sensitivity by ST segment was 48% and the specificity was 59%. These values were low because of the large number of false positive and negative ST responses in the study. It was our purpose to determine if these lowered values could be significantly improved by the R wave. Using R wave criteria, the sensitivity was 63% (P is less than 0.01) while the specificity was 79% (P is less than 0.01). The sensitivity and specificity of stress testing can be significantly improved using R wave changes.