Accession Number : ADA333371

Title :   Differences in Mechanism Between Syncope Resulting from Rapid Onset Acceleration and Orthostatic Stress

Corporate Author : AIR COMMAND AND STAFF COLL MAXWELL AFB AL

Personal Author(s) : Self, David A. ; White, Curtis D. ; Shaffstall, Robert M. ; Mtinangi, Benjamin L. ; Croft, Jennifer S.

PDF Url : ADA333371

Report Date : APR 1996

Pagination or Media Count : 41

Abstract : Orthostatically- induced syncope is accompanied by venous pooling and vasodilatation. Loss of consciousness during head-to-foot acceleration (G-LOC) in aviators may be caused by a different mechanism, as venous pooling should be prevented through the use of an anti-G suit. This research was conducted to test the hypothesis that in individuals wearing a well-fitted anti-G garment, there are no important changes in volume of dependent regions during loss of consciousness resulting from rapid onset acceleration stress. Furthermore, this work compares venous pooling patterns in G-LOC subjects to patterns seen during syncope in volunteers and patients subjected to orthostatic stress. The tilt/LBNP tests were conducted to establish what level of venous pooling was required to induce syncope in the absence of a hydrostatic component (other than 1 G) and to confirm that our equipment was sensitive enough to detect volume changes large enough to cause syncope.

Descriptors :   *G SUITS, *ORTHOSTATISM, STRESS(PHYSIOLOGY), PILOTS, HYDROSTATICS, HYPOTHESES, VEINS, CONSCIOUSNESS, VASODILATION, ACCELERATION TOLERANCE, PRESSURE SUITS, SYNCOPE.

Subject Categories : Stress Physiology
      Protective Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE