title: Enhanced recognition of ischemia by three variable analysis of the exercise stress test.
abstract: BACKGROUND
  ECG ST-segment deviations have been the standard measure of coronary artery disease (CAD) during the exercise stress test (EST). Our past research has shown other ECG variables to be significant in EST. This study evaluates the benefit of routinely combining these variables in the detection of CAD.
  
  
  METHODS
  Sequential patients (n = 439) with suspected CAD referred for EST had their cases reviewed. Clinical and ECG variables were associated with myocardial perfusion imaging (MPI) scintigrams used to detect ischemia during maximum EST.
  
  
  RESULTS
  An increase in P-wave duration was the most sensitive predictor of ischemia with a sensitivity of 64.3%, a specificity of 86.5%, and a positive predictive power (PPP) of 57.8%. ST elevation ≥ 1 mm in lead AVR had a sensitivity of 53.1%, a specificity of 78.3%, and a PPP of 41.3%. ST depression ≥ 1 mm in leads V₄-V₆ had a sensitivity of 11.2%, a specificity of 94.7%, and a PPP of 37.9%. When these variables were combined, specificity and PPP increased to 100% (p < 0.001).
  
  
  CONCLUSIONS
  EST evaluation solely by ST deviation fails to identify a significant portion of ischemic cases. Combinations of ΔPWD, ST elevation in AVR, and ST depression improved the identification of ischemia.
authors.affiliation: Memorial Heart and Vascular Institute, Long Beach Memorial Medical Center, Long Beach, CA, USA.
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Maganis
authors.forename: David A
authors.initials: DA
authors.lastname: Drimmer
authors.forename: Ferdinand B
authors.initials: FB
authors.lastname: Rojo
authors.forename: Sherief H
authors.initials: SH
authors.lastname: Gamie
authors.forename: Ronald Startt H
authors.initials: RS
authors.lastname: Selvester
authors.forename: Myrvin H
authors.initials: MH
authors.lastname: Ellestad
mesh_terms: D000465:Algorithms; D003324:Coronary Artery Disease; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: Coronary artery disease; Exercise stress test; Ischemia