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 (≥ 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 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.