Effects of bilateral hystero-salpingo-oophorectomy on exercise-induced ST-segment abnormalities in young women

Mechanism of ST segment depression during exercise tests in patients with liver cirrhosis

PURPOSE

To our experience, ST segment depression is sometimes detected in an exercise electrocardiogram (ECG) test in patients with liver cirrhosis who have no significant coronary stenosis. In this study, the mechanism of ST segment depression in liver cirrhosis was examined using (99m)Tc-methoxy-isobutyl-isonitrile (MIBI) myocardial scintigraphy.

METHODS

Six patients with liver cirrhosis (LC group), and 15 normal subjects (N group) were examined. To evaluate the level of myocardial blood flow, a Bull's eye display of myocardial blood flow was performed after dividing the left ventricle into 9 segments. Exercise myocardial scintigraphy with MIBI was performed to obtain the increase in % uptake. Angiographies were performed with a CAG system by inserting a 5 French Judkins catheter via the right femoral artery.

RESULTS

No significant coronary stenosis was found in any of the LC patients. Neither a decrease in MIBI uptake nor defect was observed on Bull's eye images from the LC group. The mean % uptake increase was 61.0 +/- 5.6% in the N group. In the LC group, although neither a decrease in MIBI uptake nor a defect was visually observed on Bull's eye images obtained during exercise, the % uptake increases (mean: 52.5 +/- 5.8%) were lower than those of the N group (p<0.05).

CONCLUSION

These findings suggest that a disorder in coronary flow reserve occurs in liver cirrhosis patients, because the decreased MIBI uptake during exercise is due to the depression of flow-mediated vasodilatation controlled by the endothelium of the coronary artery and the estrogenic digitalis action of blood flow independency.

Resting ECG is modified after oophorectomy and regresses with estrogen replacement therapy in premenopausal women

OBJECTIVE

To assess the effects of bilateral oophorectomy on the resting ECG and whether they regress with estrogen replacement therapy.

STUDY DESIGN

Twenty-six premenopausal and 15 postmenopausal women were enrolled in the present study. All women had undergone hysterectomy and bilateral ovariectomy. All women underwent 12-lead ECG on admission to hospital. A second ECG was recorded 20-25 days after surgery. After this second ECG, premenopausal women were randomly divided into two groups. The women of Group A (n=14) received transdermal ethinyl estradiol (EE). The women of Group B (n=12) did not receive any therapy. A third ECG was performed in both groups 30-35 days after randomization.

RESULTS

Bilateral oophorectomy did not induce any significant modifications in the ECG parameters of the postmenopausal women whereas in the premenopausal women, we observed a significant increment in mean duration of the T wave, a significant decrease in its amplitude and significant reduction in ST depression in V2, V3, V4 and V5. The third ECG showed regression of the ECG modifications in Group A. In the women of Group B, the second and third ECGs were not substantially different, but there were statistically significant differences between the first and third ECGs.

CONCLUSIONS

The results of the present study show that ovariectomy induces significant though not clinically evident modifications in resting ECG. These ECG changes are probably due to the sudden reduction in sex hormone plasma levels after ovariectomy. Administration of estradiol induced regression of the ECG modifications.

The specificity of exercise electrocardiography in women grouped by estrogen status

We compared the specificity of exercise electrocardiography in 1880 men and 1818 women with women grouped by menopausal and estrogen replacement status. Specificity for > or = 1 mm horizontal or downsloping ST-segment depression was determined using angiography in 781 patients and using two other nonangiography-based methods (a pretest probability-based method and a predictive accuracy-based method) in all patients. Using angiography, the specificities+/-SE were 84 +/- 2 for men, 79 +/- 3 for women, 81 +/- 5 for premenopausal women, 81 +/- 4 for postmenopausal women without estrogen replacement, and 77 +/- 5 for women on estrogen replacement. None of these were significantly different. For all patients, the respective specificities using the probability and predictive accuracy-based methods were 97 +/- 1 and 94 +/- 1 for men, 90 +/- 1 and 88 +/- 1 for women, 97 +/- 1 and 92 +/- 2 for premenopausal women, 92 +/- 4 and 88 +/- 3 for postmenopausal women without estrogen replacement, and 85 +/- 4 and 81 +/- 3 for women on estrogen replacement. (Men vs. all women groups except premenopausal women-P < 0.05). Therefore, the premenopausal women had significantly greater specificity than women on estrogen replacement (P < 0.001) and no difference in specificity with men. Women on estrogen replacement had a significantly lower specificity than postmenopausal women not on estrogen replacement (P < 0.05). These results suggest that estrogen replacement therapy and not naturally occurring estrogen has a role in producing false positive exercise electrocardiograms in women.

Beneficial effect of treatment with transdermal estradiol-17-beta on exercise-induced angina and ST segment depression in syndrome X

We investigated the acute effect of transdermal estradiol-17-beta on exercise-induced ischemia in 15 postmenopausal women (mean age 58 +/- 6 years) with syndrome X (angina pectoris, positive exercise test and normal coronary angiogram) and eight healthy women (mean age 58 +/- 5 years) in a placebo-controlled, double-blind crossover trial. Two exercise tests were performed on separate days, separated by at least 1 week, after application of placebo or 100 micrograms/24 h estradiol-17-beta. In the control group there was no difference between estradiol and placebo. Patients with syndrome X, on the other hand, showed an increased time to angina (323 +/- 99 versus 233 +/- 67 s, P = 0.0044), time to 1 mm ST depression (257 +/- 142 versus 187 +/- 122 s, P = 0.039), total exercise time (363 +/- 104 versus 323 +/- 85 s, P = 0.038), and working capacity (93 +/- 17 versus 89 +/- 15 W, P = 0.0086) during active treatment. In conclusion, estradiol-17-beta has a beneficial effect on myocardial ischemia in postmenopausal women with syndrome X and may be a useful therapeutic agent in this disease.

Comparison of the sensitivity and specificity of exercise electrocardiography in biased and unbiased populations of men and women

To assess for sex-related differences in posttest referral bias, we compared the accuracy of exercise electrocardiography in biased (coronary angiography only) and unbiased (all unselected) populations with possible coronary disease. A retrospective analysis of clinical and exercise test data from 4467 patients (788 who underwent angiography) was performed (2824 men and 1643 women). The accuracy of a positive exercise test result was assessed in the entire unbiased group with a method that used disease probability (derived with a logistic algorithm) rather than angiography results. We found that the sensitivity and specificity were significantly greater in men than in women with use of the biased or unbiased groups. When the results for the unbiased and biased groups were compared, the sensitivities for the unbiased group were significantly lower and the specificities were significantly higher than those of the biased group. These differences reflect the effects of posttest referral bias. The amounts that sensitivity decreased and specificity increased, however, was not different for men and women. Therefore, we conclude that the accuracy of exercise electrocardiography is lower in women than men irrespective of whether a biased or an unbiased group is used. However, these differences cannot be explained on the basis of sex-related differences in posttest referral bias.