Background: Treadmill exercise electrocardiography (ECG) has been used to detect restenosis in patients following percutaneous transluminal coronary angioplasty (PTCA). However, the level of sensitivity achieved using conventional criteria of ST-segment depression is too low to be clinically useful in this population.Hypothesis: QT dispersion is a sensitive method for detecting myocardial ischemia and may improve the accuracy of treadmill exercise ECG testing for detecting restenosis after PTCA.Methods: We evaluated 104 patients who underwent PTCA for the treatment of single-vessel coronary artery disease and who had no history of myocardial infarction. Treadmill exercise ECG and coronary angiograms were performed 3 months after PTCA to determine the accuracy of diagnosing restenosis based on standard ST-segment depression and QT dispersion criteria.Results: Restenosis was observed in 37 of the 104 patients (36%) 3 months after PTCA. QT dispersion immediately after exercise was significantly greater in patients with than in those without restenosis, as was the difference in QT dispersion before and immediately after exercise. The sensitivity, specificity, and accuracy of ST-segment depression criteria were 59,64, and 63%, respectively. Measurements of QT dispersion immediately after exercise (2 50 ms: positive, < 50 ms: negative) improved the sensitivity, specificity, and accuracy of treadmill ECG for predicting restenosis to 8 1,87, and 85%, respectively. Conclusions: This novel diagnostic method using QT dispersion-based criteria significantly improves the clinical usefulness of treadmill exercise ECG for detecting the presence of restenosis after PTCA.

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Background: The presence of ischemic but viable myocardium in infarcted areas is an important indication for coronary revascularization, but is often difficult to detect with the use of treadmill exercise electrocardiography (ECG). Hypothesis: QT interval dispersion (QTd) is a sensitive method for detecting myocardial ischemia and may improve the accuracy of treadmill exercise ECG testing for detecting ischemic but viable myocardium in infarcted areas. Methods: Forty‐five patients with Q‐wave anterior wall myocardial infarctions who underwent treadmill exercise ECG, exercise reinjection thallium‐201 (201T1) scintigraphy, radionuclide angiocardiography, and coronary angiography 1 month after infarction were enrolled in this study. The presence of viable myocardium in the infarct area was determined by exercise reinjection 201T1 scintigraphy. Patients who had no redistribution in the infarct area after reinjection were included in Group 1, and those with redistribution were included in Group 2. Results: QTd immediately after exercise, and the difference between QTd before and immediately after exercise, were significantly greater in Group 2 than in Group 1. The sensitivity, specificity, and accuracy of conventional ST‐segment depression criteria for detecting viable myocardium in the infarct area were 48,64, and 56%, respectively. The measurement of QTd immediately after exercise (abnormal: ≥ 70 ms; normal: < 70 ms) improved the sensitivity, specificity, and accuracy to 78,82, and 80%, respectively. Conclusions: This novel diagnostic method using QTd‐based criteria significantly improves the clinical usefulness of treadmill exercise ECG testing for detecting ischemic but viable myocardium in infarct areas in patients with healed Q‐wave anterior wall myocardial infarctions.

Many studies have shown that there is a strong correlation between hostility and coronary artery disease; however, the pathogenic mechanisms by which hostility causes coronary artery disease have not been identified. Several studies have shown that hostility is associated with increased cardiovascular reactivity to mental stress. Sloan and colleagues used mental arithmetic and the Stroop Color-Word Task as psychological stressors and suggested that hostility is associated with diminished cardiac vagal control. It is supposed that the diminished cardiac vagal control results in uncontrollability of increased heart rate under stressful conditions so performance on mental stress tasks is poor. However, performance was not analyzed on the Stroop Color-Word Task. If hostility influences the autonomic nervous system, the performance of this mental stress task may also differ according to extent of hostility. In the present study, whether hostility disturbed performance of a mental stress task and the practice on it was examined. Subjects completed the Cook-Medley Hostility Scale and were divided into three groups (High, Middle, and Low) by their total scores and three subscales (Cynicism, Hostile Affect, and Aggressive Responding). They also completed the Stroop Color-Word Task. Analysis showed practice by High and Middle scoring groups on Aggressive Responding had a significantly smaller effect than that by Low scoring groups. The pathogenic mechanisms by which hostility may underlie coronary artery disease were discussed.