WISE-2005: orthostatic tolerance is poorly predicted by acute changes in cardiovascular variables
| Autor: | K R, Beavers, D K, Greaves, P, Arbeille, R L, Hughson |
|---|---|
| Rok vydání: | 2008 |
| Předmět: |
Adult
Lower Body Negative Pressure Time Factors Cardiovascular Deconditioning Hemodynamics Blood Pressure Stroke Volume Space Flight Dizziness Head-Down Tilt Heart Rate Humans Female Vascular Resistance Dietary Proteins Cardiac Output Pulse Weightlessness Countermeasures Exercise Bed Rest Weightlessness Simulation |
| Zdroj: | Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology. 14(1) |
| ISSN: | 1077-9248 |
| Popis: | Twenty-four (24) healthy women from 25-40 years of age underwent orthostatic tolerance tests consisting of passive tilt and lower body negative pressure before and after completing 60-days of continuous -6 degree head down tilt bed rest (HDBR). Prior to HDBR, participants were assigned to one of three groups: control, exercise or nutrition. We aimed to identify any acute head up tilt changes in mean arterial pressure, pulse pressure, total peripheral resistance, cardiac output, stroke volume, or heart rate, which might predict tolerance or changes in tolerance with HDBR. Generally, these attempts were largely unsuccessful. The results indicate that the mechanisms of orthostatic failure are not strongly related to the way in which the body responds to the initial challenge. Additionally, the observation that some variables were predictive of tolerance before and not after tilt may indicate a change in the strategies used to maintain blood pressure, or differential adaptations to HDBR. |
| Databáze: | OpenAIRE |
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