Accession Number:

ADA333371

Title:

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

Descriptive Note:

Corporate Author:

AIR COMMAND AND STAFF COLL MAXWELL AFB AL

Report Date:

1996-04-01

Pagination or Media Count:

41.0

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 tiltLBNP 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.

Subject Categories:

  • Stress Physiology
  • Protective Equipment

Distribution Statement:

APPROVED FOR PUBLIC RELEASE