Mulvagh SL, Charles JB, Fortney SM, Bungo MW.
Circulation. 1990 Oct; 82: III-515.
National Aeronautical and Space Administration, Houston, TX.
To determine whether altered peripheral vascular resistance contributes to orthostatic intolerance observed in space shuttle crewmembers on return to the 1G environment, echocardiographic studies were performed preflight and 1-2 hours, 2, 3, 4-6, and 7-10 days postflight during 1988-89. 24 crewmembers of 7 shuttle missions lasting 4 to 5 days had 2-dimensionally-directed M-mode echocardiograms done during 5 min each of supine and standing positions; blood pressures (BP) were obtained at each minute, and cardiac index (CI) was derived from echocardiographic volume determinations (Teicholz formula). Total peripheral resistance index (TPRI) was determined by mean arterial pressure/CI. The orthostatic response (mean standing value - mean supine value) on landing day compared to preflight was decreased from 17.9 to 10.8 units for TPRI (p < or = .03) and from 19 to 13 mmHg for diastolic BP (p < or = .01). These changes returned to preflight values within 2 days post-flight. These findings suggest that diminished peripheral vascular tone occurs after exposure to microgravity and may be caused by autonomic dysfunction.
Publication Types:
Keywords:
- Blood Pressure
- Echocardiography
- Space Flight
- Vascular Resistance
- Weightlessness
- ultrasonography
- NASA Center JSC
- NASA Discipline Cardiopulmonary
- NASA Discipline Number 00-00
- NASA Discipline Number 14-10
- NASA Program Flight
- NASA Program Space Physiology and Countermeasures
Other ID:
UI: 102212532
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