PHYSIOLOGICAL PARAMETERS THAT PREDICT ORTHOSTATIC INTOLERANCE AFTER SPACEFLIGHT
(AORTA)
Research Area: Cardiovascular and Respiratory Systems
Expedition(s): 7, 8
Principal Investigator(s): ● John M. Karemaker, University of Amsterdam,
Netherlands
RESEARCH OBJECTIVES
Physiological Parameters That
Predict Orthostatic Intolerance After
Spaceflight (Aorta) plans to predict
orthostatic intolerance due to
microgravity before and after return
from microgravity. This investigation
categorizes the cardiovascular
reaction pattern of a crew member
and acts as a predictor for the
outcome of the test.
RESULTS
Data indicated that blood pressure
(BP) levels in space were not very
different from preflight; the circadian BP rhythm appeared dampened. Only daytime diastolic
pressures and nighttime heart rate (HR) were significantly lower in space. However, compared
to the effect of a control tilt maneuver on the ground, even lower BP values might have been
expected. Striking were the BP and HR surges during the working days in space, often related to
stressful moments such as live appearances on public broadcast. Systemic vascular resistance
(SVR) dropped during the night, unlike HDT. Thus, actual spaceflight refutes earlier findings in
HDT, both for BP levels and for daytime to nighttime changes.
PUBLICATION(S)
Karemaker JM, Berecki-Gisolf J. Twenty-four hour blood pressure in space: The dark side of
being an astronaut. Respiratory Physiology and Neurobiology. 2009;169:S55-S58. doi:
10.1016/j.resp.2009.05.006.
Berecki-Gisolf J, Immink RV, Van Lieshout JJ, Stok WJ, Karemaker JM. Orthostatic blood pressure
control before and after spaceflight, determined by time-domain baroreflex method. Journal of
Applied Physiology. May 2005;98(5):1682-1690. doi: 10.1152 /japplphysiol.01219.2004.
This investigation is complete and all results are published.
Subjects lie on tilt tables and are being monitored for physiological
changes simulating headward fluid shift in microgravity. ESA image.