Recovery time from myocardial ischemia induced by exercise test: correlation with duration of ischemia during the test and with the extent of coronary disease
Ghio, S.; Eleuteri, E.; de Servi, S.; Falcone, C.; Auguadro, C.; Quaglini, S.; Berzuini, C.; Specchia, G.; Montemartini, C.
Giornale Italiano di Cardiologia 24(9): 1069-1076
1994
ISSN/ISBN: 0046-5968 PMID: 7995488 Document Number: 430188
Aim of this study was to evaluate the factors affecting the duration of the recovery time (RT) after a positive exercise stress test and to define its relationship with the extent of coronary artery disease (CAD). We studied 109 consecutive patients with a positive exercise test and proven coronary disease. RT was neither related to the severity of CAD, nor to exercise duration, rate-pressure product at the end of the exercise and maximum ST segment depression. A significant linear relationship was found between RT and the time of ischemia during exercise (IT) (r = 0.66, p < .001). This relationship was analyzed separately in patients (pts) with advanced (Group I) and in pts with less severe CAD (Group II). The regression line of the data showed a similar slope but a higher y-axis intercept in Group I than in Group II (p < .05). The RT/IT ratio was in fact significantly higher in Group I than in Group II (3.0 +/- 1.3 vs 1.7 +/- 0.7, p < .0001). Discriminant analysis was performed to predict the presence of advanced CAD: using the RT/IT ratio instead of RT correct classification rate of the model increased from 81.4 to 86.7%, predictive accuracy from 73.7 to 85.3% and true negative rate from 85.3 to 87.4%. These results suggest that the normalization of the recovery time by time of ischemia during the test provides a simple and useful index for the prediction of the extent of coronary artery disease.