Temporal changes in cardiac function and cerebral blood flow during sequential postmenopausal hormone replacement

OBJECTIVE: The purpose was to assess the temporal changes in cardiac functi on and cerebral blood flow during postmenopausal administration of estrogen with and without progestogen. STUDY DESIGN: Sixteen postmenopausal volunteers were assessed during estrad iol plus sequential norethindrone acetate and placebo in two 12-week period s. Temporal changes were measured by magnetic resonance flow mapping 8 time s. RESULTS: Systemic vascular resistance was reduced during estradiol (-6.9%; P < .05), declined further during the addition of norethindrone acetate, an d was accompanied by an increase in stroke volume (maximum increase, 5.2%; P < .05) without fluid retention. Both systolic (-5 mm Hg; P = .03) and dia stolic (-3 mm Hg; P = .03) blood pressure were reduced during estradiol. Ce rebral blood flow was reduced after 9 weeks of hormone replacement therapy (-37 mL/min; P = .01) but increased to baseline after the addition of noret hindrone acetate. CONCLUSIONS: Sequential hormone replacement therapy is associated with chan ges in cardiac function, which are of therapeutic potential in cardiovascul ar disorders. Sequential hormone replacement therapy exhibits an overall ne utral effect on cerebral blood flow.