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

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.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1996
Accession Number
ADA333371

Entities

People

  • Benjamin L. Mtinangi
  • Curtis D. White
  • David A. Self
  • Jennifer S. Croft
  • Robert M. Shaffstall

Organizations

  • Air Command and Staff College

Tags

Communities of Interest

  • Biomedical
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Air Force
  • Blood
  • Blood Volume
  • Capacitance
  • Cardiovascular Physiological Phenomena
  • Computer Programs
  • Consciousness Disorders
  • Electrical Impedance
  • G Suits
  • Health Services
  • Heart Rate
  • Hydrostatic Pressure
  • Impedance
  • Medical Personnel
  • Pressurization
  • Students
  • Universities

Readers

  • Cardiovascular Physiology
  • Materials Science