Effect Of Headward And Foward Accelerations On The Cardiovascular System
Report Number: WADD TR 60-634
Author(s): Wood, Earl H., Marshall, Hiram W., Lindberg, Evan F., Headley, Robert N., Sutterer, William F.
Corporate Author(s): The Mayo Foundation; Biomedical Laboratory Aerospace Medical Laboratory
Laboratory: Biomedical Laboratory
Date of Publication: 1961-01
Pages: 54
Contract: AF 33(616)-5938
DoD Project: 7220
DoD Task: 71742
Identifier: AD0255298
Abstract:
The purpose of this research was to measure cardiac output and related physiological variables in human subjects exposed to acceleration stress in various body orientations. Results of these experiments indicate that an average decrease in cardiac output of 22% of control values occurs in subjects exposed to headward accelerations of 4 g. no systematic change in cardiac output could be demonstrated when these same subjects were exposed to forward accelerations of up to 5 g. As the duration of these exposures to acceleration were increased to 10 minutes, no further alterations in output were demonstrable. Exposure to headward acceleration caused decreases in right atrial and esophageal (intrathoracic) pressure and in the oxygen saturation of arterial blood which were proportional to the magnitude of the acceleration. Forward acceleration, however, cause relatively large increases in right atrial and esophageal pressure but a decrease in arterial oxygen saturation. The decrease in arterial oxygen saturation was prevented by breathing 99.6% oxygen
Provenance: IIT
Author(s): Wood, Earl H., Marshall, Hiram W., Lindberg, Evan F., Headley, Robert N., Sutterer, William F.
Corporate Author(s): The Mayo Foundation; Biomedical Laboratory Aerospace Medical Laboratory
Laboratory: Biomedical Laboratory
Date of Publication: 1961-01
Pages: 54
Contract: AF 33(616)-5938
DoD Project: 7220
DoD Task: 71742
Identifier: AD0255298
Abstract:
The purpose of this research was to measure cardiac output and related physiological variables in human subjects exposed to acceleration stress in various body orientations. Results of these experiments indicate that an average decrease in cardiac output of 22% of control values occurs in subjects exposed to headward accelerations of 4 g. no systematic change in cardiac output could be demonstrated when these same subjects were exposed to forward accelerations of up to 5 g. As the duration of these exposures to acceleration were increased to 10 minutes, no further alterations in output were demonstrable. Exposure to headward acceleration caused decreases in right atrial and esophageal (intrathoracic) pressure and in the oxygen saturation of arterial blood which were proportional to the magnitude of the acceleration. Forward acceleration, however, cause relatively large increases in right atrial and esophageal pressure but a decrease in arterial oxygen saturation. The decrease in arterial oxygen saturation was prevented by breathing 99.6% oxygen
Provenance: IIT