| Identification of the human electrical impedance indifferent point: a surrogate for the volume indifferent point? | |
| | |
MedLine Citation:
|
PMID: 19672616 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Head-up tilt (HUT) redistributes approximately 700 mL of blood to the dependent regions. In a gravitational field, hydrostatic pressure is balanced against vascular compliance, resulting in a hydrostatic indifferent point (HIP) whose location should be coincident with an indifferent point for volume (VIP). Cardiac filling is determined by the hydrostatic gradient between the HIP/VIP and right atrium. We employed segmental impedance to examine blood volume redistribution during HUT and estimate the location of the VIP. During HUT, impedance increased in the chest and decreased in the lower abdomen, presumably due to blood volume shifts. Using a non-linear model to relate blood volume shifts to the hydrostatic gradient, we estimated the location of the electrical impedance indifferent point between the xyphoid process and iliac crest, at 64.5 +/- 2.6% of an individual's height. This method may provide a quantitative framework to assess the effects of blood volume distribution on tilt tolerance. |
| | |
Authors:
|
Sara S Jarvis; James A Pawelczyk |
Related Documents
:
|
1789136 - Sources of variation in 133xenon washout after subcutaneous injection on the abdomen. 12352466 - Regulation of blood flow and microcirculation resistance in rabbit bladder. 47936 - Rational use of albumin and plasma substitutes. 10192086 - Treatment of heartwater: potential adverse effects of furosemide administration on cert... 2375956 - A two-dimensional numerical analysis of unsteady flow in the carotid artery bifurcation... 3428386 - Sem studies on the functional morphology of the rabbit ciliary process vasculature. |
Publication Detail:
|
Type: Clinical Trial; Journal Article; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S. Date: 2009-08-12 |
Journal Detail:
|
Title: European journal of applied physiology Volume: 107 ISSN: 1439-6327 ISO Abbreviation: Eur. J. Appl. Physiol. Publication Date: 2009 Nov |
Date Detail:
|
Created Date: 2009-10-16 Completed Date: 2010-01-05 Revised Date: - |
Medline Journal Info:
|
Nlm Unique ID: 100954790 Medline TA: Eur J Appl Physiol Country: Germany |
Other Details:
|
Languages: eng Pagination: 473-80 Citation Subset: IM |
Affiliation:
|
Department of Kinesiology, The Pennsylvania State University, University Park, PA 16802, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Adolescent Adult Anthropometry / methods* Biological Markers / analysis* Blood Pressure / physiology Blood Volume / physiology* Body Composition / physiology* Electric Impedance Exercise Test Female Fluid Shifts / physiology* Heart Rate / physiology Humans Male Models, Biological Posture / physiology Young Adult |
| Grant Support | |
ID/Acronym/Agency:
|
MO1RR10732/RR/NCRR NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Biological Markers |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Body height and ocular diseases. The Beijing Eye Study.
Next Document: Strenuous exercise increases late outgrowth endothelial cells in healthy subjects.