[Changes in QT dispersion during the exercise test in women with syndrome X].

UNLABELLED

The aim of the present study was to examine the effect of exercise test on QT dispersion (dQT) and to compare the result in women with syndrome X with women with coronary artery disease and normal subjects. We examined 53 women in mean age 54.2 +/- 9.2 who were divided into groups: 20 women with one-vessel coronary artery disease (group I), 19 women with syndrome X (group II) and 14 healthy control women (group III). All subjects underwent a modified Bruce protocol exercise test and QT intervals were measured manually at rest and peak exercise. The value of dQT was calculated as a difference between the longest and the shortest measured value in each of the 12 ECG leads. Corrected QT (dQTc) dispersion was measured after the QT interval was corrected with Bazett's formula. There were no significant differences in rest values of dQT between groups but rest dQTc was significantly greater in group I and II then in group III. We observed significant increase in dQT and dQTc on peak exercise in group I and II when compared with group III.

CONCLUSION

At rest dQTc is significantly greater in women with syndrome X and coronary artery diseases in comparison with control subjects. The exercise caused increase in the value of dQT and dQTc both in women with syndrome X and coronary artery disease. The value of dQT and dQTc makes impossible to differentiate between women with syndrome X and women with coronary artery disease.