Related Experiment Videos
Effect of short-term hormone replacement therapy on left ventricular mass and contractile function
C K Sites1, M D Tischler, J A Blackman
1Department of Obstetrics and Gynecology, University of Vermont College of Medicine, Burlington 05405, USA.
Objective:
To determine the effect of hormone replacement therapy (HRT) on cardiac structure and function and whether these changes are related to changes in blood volume.
Design:
Open-label pilot study.
Setting:
Academic medical center.
Patient(S):
Eighteen healthy postmenopausal women.
Intervention(S):
We administered medroxyprogesterone acetate orally, 5 mg/d for 2 months followed by 2 months of oral sequential 17beta-estradiol, 1 mg/d plus medroxyprogesterone acetate, 10 mg/d for the last 12 days of each month.
Main Outcome Measure(S):
Cardiac output, stroke volume, heart rate, end diastolic volume, end systolic volume, ejection fraction, and left ventricular mass were measured by echocardiography; blood and plasma volumes were measured using 125I-albumin dilution.
Result(S):
Cardiac output, stroke volume, left ventricular mass, end diastolic volume, and ejection fraction increased by 12.8%, 11.7%, 9.4%, 7.2%, and 10.9%, respectively, by 16 weeks. End systolic volume decreased, whereas heart rate was unaffected. There was a significant increase in blood volume (5.2%) and plasma volume (4.8%) from baseline during treatment, which could explain the increased cardiac output but not the increased ejection fraction.
Conclusion(S):
Hormone replacement therapy causes modest but significant increases in cardiac output, ejection fraction, and left ventricular mass. These pilot data suggest a direct myocardial effect of HRT that is preload independent.