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.