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The relation between venous reserve capacity and low plasma volume
Ineke Krabbendam1, Ben J Janssen, Arie P J Van Dijk
1Department of Obstetrics and Gynecology, Radboud University of Nijmegen Medical Centre, Nijmegen, The Netherlands. i.krabbendam@obgyn.umcn.nl
Reproductive Sciences (Thousand Oaks, Calif.)
|June 27, 2008
Summary
Low plasma volume (LPV) in nonpregnant women is linked to reduced venous reserve capacity (VRC), increasing presyncope risk during head-up tilt tests. This suggests LPV may impair cardiovascular adaptation.
Area of Science:
- Cardiovascular Physiology
- Reproductive Medicine
Background:
- Prepregnant low plasma volume (LPV) is a risk factor for gestational hypertensive disease.
- The impact of LPV on venous reserve capacity (VRC) remains largely unexplored.
Purpose of the Study:
- To investigate the relationship between LPV and VRC in nonpregnant women.
- To determine if LPV affects cardiovascular and autonomic responses during head-up tilt.
Main Methods:
- Fifty-two nonpregnant women with a history of preeclampsia or miscarriage were studied.
- Plasma volume, stroke volume, cardiac output, blood pressure, and heart rate were assessed.
- Autonomic responses to stepwise head-up tilt were analyzed.
Main Results:
- Twelve participants exhibited LPV, with a higher incidence of presyncope compared to normal plasma volume (NPV) subjects.
- Women with LPV but without presyncope maintained comparable circulatory responses to NPV women, but with higher heart rates.
- LPV was associated with reduced VRC, indicated by presyncope and altered cardiovascular responses.
Conclusions:
- LPV diminishes the capacity to tolerate head-up tilt, suggesting a reduced VRC.
- The findings indicate that LPV may compromise the body's ability to adapt to orthostatic stress.
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