Document Detail

Cardiovascular and pulmonary responses to increased acceleration forces during rest and exercise.
MedLine Citation:
PMID:  22606865     Owner:  NLM     Status:  In-Process    
BACKGROUND: The reduced cardiac output (CO) secondary to increased acceleration forces (+Gz) has applicability to daily life and pathophysiology. Increased +Gz and reduced CO affect the lung, resulting in reduced oxygen transport. A variety of studies have examined tolerance to high +Gz.
METHODS: The present study examines the effect of +1 to +3 Gz on steady-state cardiopulmonary variables at rest and while exercising at +2 Gz and +3 Gz. This study also looks at the deterioration of steady-state cardiopulmonary variables with sustained increased +Gz and after de-training in eight male centrifuge trained subjects.
RESULTS: CO (-1.53 L x min(-1)/+Gz), stroke volume (-30 ml/+Gz, SV), and pulmonary diffusing capacity (-3.42 ml x mmHg(-1)/+Gz, DL(co)) decreased linearly with increased +Gz at rest while heart rate (23 bpm/+Gz, HR), total peripheral resistance (0.0095 TPRU/Gz TPR), mean arterial pressure (13.2 mmHg/+Gz, MAP), and ventilation (4.13 L x min(-1)/+Gz, V(E)) increased linearly. During graded exercise, CO and SV increased less at +2 Gz and +3 Gz while MAP and VE increased more. Failure to endure increased +Gz and the effects of de-training were primarily due to the inability to regulate MAP.
DISCUSSION: The incremental increase in increased +Gz from 1 to 3 resulted in increased MAP, which was accomplished by increasing TPR sufficiently so as to offset the reduced CO. The effects of increased +Gz and reduced CO compromised lung function and oxygen transport (-18-30%), thus compromising exercise capacity. The failure to regulate MAP at lower increased +Gz levels resulted in intolerance to higher increased +Gz.
David R Pendergast; Albert Olszowka; Leon E Farhi
Related Documents :
24816885 - The acute response of apoptosis and migration to resistance exercise is protocol-depend...
7836145 - Alteration of plasma endothelin-1 by exercise at intensities lower and higher than vent...
3769905 - The effects of high intensity exercise on muscle and plasma levels of alpha-ketoisocapr...
1136935 - Quinidine plasma concentration and exertional arrhythmia.
21195495 - Diagnosing fatigue in gait patterns by support vector machines and self-organizing maps.
8044935 - Effects of l-arginine on impaired acetylcholine-induced and ischemic vasodilation of th...
Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  83     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2012 May 
Date Detail:
Created Date:  2012-05-21     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  488-95     Citation Subset:  IM; S    
Center for Research and Education in Special Environments, Department of Physiology and Biophysics, School of Medicine and Biomedical Sciences, University at Buffalo, 124 Sherman Hall, Buffalo, NY 14214, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Hypergravity conditioning on ileal movements in rats.
Next Document:  Flight experience and the perception of pitch angular displacements in a gondola centrifuge.