Study of Cardiovascular Deconditioning Under Weightlessness Conditions (CardioScience) - 01.09.14
Science Objectives for Everyone Information Pending
Science Results for Everyone Information Pending
Faculty of Medicine Lyon Grange Blanche, Lyon, , France
Sponsoring Space Agency
European Space Agency (ESA)
ISS Expedition Duration
August 2001 - December 2001
Previous ISS Missions
The Cardioscience program on board Andromede aims to test ways of countering the factors (and measuring their effects) associated to orthostatic hypotension, which is caused by cardiovascular deconditioning affecting astronauts during spaceflight. These factors include: decreased volume of plasma, changes to hormones that control blood volume, a change in the sympathetic or parasympathetic balance and in the baroreceptor that induces changes in blood pressure, increased vascular retention in the legs (a tendency for the vein system to retain blood), diminished peripheral vascular resistance, neuro-vestibular ailments such as vertigo, and altered metabolism (weight loss). The scientific experiments will study cardiac regulation and sympathetic and parasympathetic balance in weightless conditions. They also enable exploitation of the capabilities of both types of equipment used the Portapress unit and a Doppler unit.
The experiment is divided into two parts: Study of vegetative regulation of arterial pressure and heartbeat, and study of cardiac and peripheral arterial regulation. Arterial pressure is maintained around physiological values by regulatory mechanisms that involve the vegetative nervous system. Pressure is regulated by varying heartbeat and peripheral arteriole resistance. Joint analysis of beat-by-beat arterial pressure and cardiac frequency variations recorded by the Portapress unit during the experiment provides information on how the autonomous nervous system, both sympathetic and parasympathetic, functions. The Portapress unit is a non-invasive piece of equipment that, over long periods, continuously records the electrocardiogram and the blood pressure curve as well as respiratory movement. This machine is interesting in two waysmedically but also scientificallyas it allows us to study cardiac regulation by the central nervous system thanks to mathematical analysis of recorded signals. Cardiovascular reactivity to stress can be evaluated during a mental arithmetic exercise. This part of the experiment involves several stages: Stabilization for 10 minutes for calibration, Measurements at rest for 10 minutes, Controlled breathing measurements for 5 minutes, Measurements during a period of mental stress for 5 minutes (arithmetic calculation), Forced breathing measurements for 2 minutes, and Measurements at rest for 2 minutes. Then there is the study of cardiac and peripheral arterial regulation. Cardiac and peripheral arterial regulation are studied using the Portapress unit and Doppler unit. The latter enables concurrent measurement of blood flow speed through three arteries. To broaden the investigative scope, each of the channels can take two measurements. The Doppler unit will study: cerebral artery, internal carotid, primitive carotid, aorta, femoral artery, peripheral arteriesradial, tibial, humeral and cubial. This part of the experiment will have 3 phases: Study of peripheral flow redistribution, Study of sympathetic and parasympathetic effects at central and peripheral levels, Study of the influence of neck and otolithic muscles on cardiovascular regulation during head movements.
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Cardioscience equipment. Image courtesy of Energia.
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