title: Exaggerated atrial repolarization waves as a predictor of false positive exercise tests in an unselected population.
abstract: The authors previously postulated that a markedly downsloping PR-segment might be a marker for exaggerated atrial repolarization waves and demonstrated PR-segment appearance to be an independent predictor of a false positive exercise test. This study was conducted to determine the sensitivity, specificity, and predictive value of markedly downsloping PR-segments for predicting false positive exercise tests. The study group consisted of 82 consecutive patients with a positive exercise test (> or = 1.0 mm horizontal ST depression) and a normal resting electrocardiogram. Tests were predicted to be false positive based on previously defined criteria: (1) markedly downsloping PR-segments in two or more of leads II, III, and aVF and (2) exercise duration 4 minutes or longer. Patients were then classified according to available clinical information (coronary angiography and radionuclide stress testing) into true positive (due to myocardial ischemia, n = 62) and false positive (n = 20) groups. The sensitivity, specificity, and predictive value of the PR-segment/exercise duration criterion for predicting a false positive test were 70, 74, and 47%, respectively. Patients with false positive tests also had higher heart rates (158 +/- 16 vs 136 +/- 20 beats/min, P < .001) and less frequent chest pain (15 vs 46%, P = .017) during the exercise test. Patients with false positive exercise tests can be recognized by the achievement of a high peak exercise heart rate, the absence of exercise-induced chest pain, and the appearance of markedly downsloping PR-segments in the inferior leads.
authors.affiliation: Division of Cardiology, University of North Carolina at Chapel Hill, USA.
authors.forename: P M
authors.initials: PM
authors.lastname: Sapin
authors.forename: M B
authors.initials: MB
authors.lastname: Blauwet
authors.forename: G G
authors.initials: GG
authors.lastname: Koch
authors.forename: L S
authors.initials: LS
authors.lastname: Gettes
mesh_terms: D016275:Atrial Function / Q000502:physiology*; D006328:Cardiac Catheterization; D016022:Case-Control Studies; D004562:Electrocardiography; D005080:Exercise Test; D005189:False Positive Reactions; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000453:epidemiology; D015588:Observer Variation; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D013997:Time Factors; D015646:Ventriculography, First-Pass
chemical_list: D013794:Thallium Radioisotopes