Formerly preeclamptic women with a subnormal plasma volume are unable to maintain a rise in stroke volume during moderate exercise.
BACKGROUND
In formerly preeclamptic women with a low plasma volume, the recurrence rate of preeclampsia is higher than in women with a normal prepregnant plasma volume. In a recent study, we demonstrated that the low plasma volume subgroup also had a subnormal venous capacitance. In the present study, we determined the impact of subnormal plasma volume on the hemodynamic response to moderate exercise.


METHODS
We performed this study in the follicular phase of the menstrual cycle, in 31 formerly preeclamptic women with a subnormal plasma volume (low-PV) and eight parous controls. The exercise consisted of 60 minutes of cycling in the supine position at 35% of the individualized maximum capacity. Before, during, and after cycling, we measured the percentage change in heart rate, stroke volume, and cardiac output. Before and after exercise, we measured the effective renal plasma flow (ERPF, para-amino-hippurate [PAH] clearance), glomerular filtration rate (GFR, inulin clearance), circulating levels of alpha-atrial natriuretic peptide (alpha-ANP), and active plasma renin concentration (APRC).


RESULTS
The response to exercise of formerly preeclamptic women with a subnormal plasma volume differed from that in controls by a lack of rise in stroke volume, a smaller rise in cardiac output and alpha-ANP, and a greater fall in GFR. The responses in heart rate, ERPF, and APRC did not differ between the two groups.


CONCLUSIONS
The response to moderate exercise of formerly preeclamptic women with a subnormal plasma volume differs from that in healthy parous controls with a normal plasma volume and suggests a lower capacity to raise venous return in conditions of a higher demand for systemic flow. The lower capacity to raise venous return in these conditions is associated with more cardiovascular drift. The physiologic consequence is a lower aerobic endurance performance during moderate exercise.
Aardenburg
Robert
R
Department of Obstetrics and Gynecology, University Hospital Maastricht, Maastricht, The Netherlands. R.Aardenburg@og.unimaas.nl
Spaanderman
Marc E
ME
van Eijndhoven
Hugo W
HW
de Leeuw
Peter W
PW
Peeters
Louis L
LL
D000328:Adult; D009320:Atrial Natriuretic Factor / Q000097:blood; D002302:Cardiac Output / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D016015:Logistic Models; D010953:Plasma Volume / Q000502:physiology*; D011225:Pre-Eclampsia / Q000503:physiopathology; D011247:Pregnancy; D017595:Renal Plasma Flow / Q000502:physiology; D012083:Renin / Q000097:blood; D013318:Stroke Volume / Q000502:physiology*; D018924:Vascular Capacitance / Q000502:physiology*
D009320:Atrial Natriuretic Factor; D012083:Renin