Objective: The aim of the present study was to evaluate possible variations in cardiac hemodynamic parameters related to the natural changes of ovarian estrogen production.
Methods: Forty postmenopausal women aged 52.7 +/- 4.6 years, randomized into two groups (20 patients in each group) according to the administration (group A) or not (group B) of estroprogestin replacement therapy (ERT), were examined using thoracic electrical bioimpedence.
Results: After 6 months of therapy, we observed the following: (1) the mean end-diastolic index was significantly higher in group A than in group B (70.27 and 57.13 mL/m2, respectively) (p < 0.05); (2) the mean acceleration index, indicator of heart contractility, and the mean cardiac index rate, indicators of cardiac performance, were significantly higher in group A than in group B (mean, 1.35 vs. 0.76 s [p < 0.01] and mean, 3.22 vs. 2.34 L/min/m2 [p < 0.05], respectively); and (3) the patients treated with ERT showed systemic vascular resistance index values significantly lower than the controls (mean, 2280 vs. 3150 fOhm/m2 [p < 0.01]), achieving standard levels after 6 months of therapy. Furthermore, the acceleration index showed a significant increase, within group A, between the third and sixth month of ERT (0.91 vs. 1.35 s [p < 0.05]).
Conclusions: Our findings suggest that postmenopausal women treated with a 6-month course of ERT have significantly improved end-diastolic index, heart contractility index, cardiac index, and systemic vascular resistance, whereas 3 months of ERT does not seem to induce the same effects. In our study, thoracic electrical bioimpedence was shown to be a sensitive and specific method of analysis with a very low cost of administration.