The relation between venous reserve capacity and low plasma volume.
OBJECTIVE
Prepregnant low plasma volume (LPV) is associated with subsequent gestational hypertensive disease. It is unknown to what extent an LPV affects the venous reserve capacity (VRC). We tested the hypothesis that LPV reduces the VRC, as indicated by presyncope or altered cardiovascular changes in response to head-up tilt.


METHODS
In 52 nonpregnant women with a history of preeclampsia or recurrent miscarriage, the authors assessed plasma volume, stroke volume, and cardiac output and determined blood pressure, heart rate, and autonomic responses to stepwise inflicted head-up tilt.


RESULTS
12 participants had LPV, which related to presyncope when compared with subjects with normal plasma volume (NPV). Women with LPV without presyncope demonstrated a circulatory response comparable to NPV women at the expense of consistently higher heart rate.


CONCLUSIONS
LPV decreases the capacity to cope with head-up tilt without affecting the response pattern, suggesting reduced VRC.
Krabbendam
Ineke
I
Department of Obstetrics and Gynecology, Radboud University of Nijmegen Medical Centre, Nijmegen, The Netherlands. i.krabbendam@obgyn.umcn.nl
Janssen
Ben J
BJ
Van Dijk
Arie P J
AP
Jongsma
Henk W
HW
Oyen
Wim J G
WJ
Lotgering
Fred K
FK
Spaanderman
Marc E A
ME
D000328:Adult; D001794:Blood Pressure / Q000502:physiology; D002302:Cardiac Output / Q000502:physiology; D005260:Female; D018475:Head-Down Tilt / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D046110:Hypertension, Pregnancy-Induced / Q000503:physiopathology; D010953:Plasma Volume / Q000502:physiology*; D049590:Postpartum Period; D011225:Pre-Eclampsia / Q000503:physiopathology; D011247:Pregnancy; D013575:Syncope / Q000503:physiopathology; D018924:Vascular Capacitance / Q000502:physiology*