Document Detail


Parasympathetic heart rate modulation during parabolic flights.
MedLine Citation:
PMID:  12811567     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
During parabolic flight short periods of microgravity and hypergravity are created. These changes influence cardiovascular function differently according to posture. During the 29th parabolic flight campaign of the European Space Agency (ESA), the electrocardiogram (ECG) was recorded continuously in seven healthy volunteers in two positions (standing and supine). Five different phases were differentiated: 1 g (1 g=9.81 m/s(2)) before and after each parabola, 1.8 g at the ascending leg of the parabola (hypergravity), 0 g at the apex, 1.6 g at the descending leg (hypergravity). We assessed heart rate variability (HRV) by indices of temporal analysis [mean RR interval (meanRR), the standard deviation of the intervals (SDRR), and the square root of the mean squared differences of successive intervals (rMSSD) and coefficient of variation (CV)]. In the supine position no significant differences were shown between different gravity phases for all HRV indices. In the standing position the 0 g phase showed a tendency towards higher values of meanRR compared to the control and to the other phases ( p=NS). SDRR, rMSSD and CV were significantly higher compared to control ( p<0.05). Significantly higher values for meanRR in the supine position at 1 g and hypergravity ( p<0.05) were found when compared to standing. SDRR was significantly higher at 0 g in the standing position compared to supine [95 (44) ms vs. 50 (15) ms; p<0.05] and lower in other phases. rMSSD and CV showed the same trend ( p=NS). We confirm that, during parabolic flights, position matters for cardiovascular measurements. Time domain indices of HRV during different gravity phases showed: (1) higher vagal modulation of the autonomic nervous system in microgravity, when compared with normo- or hypergravity in standing subjects; and (2) no differences in supine subjects between different g phases.
Authors:
F Beckers; B Seps; D Ramaekers; B Verheyden; A E Aubert
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Publication Detail:
Type:  Clinical Trial; Comparative Study; Journal Article; Research Support, Non-U.S. Gov't     Date:  2003-06-13
Journal Detail:
Title:  European journal of applied physiology     Volume:  90     ISSN:  1439-6319     ISO Abbreviation:  Eur. J. Appl. Physiol.     Publication Date:  2003 Sep 
Date Detail:
Created Date:  2003-09-23     Completed Date:  2004-09-13     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  100954790     Medline TA:  Eur J Appl Physiol     Country:  Germany    
Other Details:
Languages:  eng     Pagination:  83-91     Citation Subset:  IM    
Affiliation:
Laboratory of Experimental Cardiology, University Hospital Gasthuisberg O/N, Herestraat 49, 3000 Leuven, Belgium.
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MeSH Terms
Descriptor/Qualifier:
Adaptation, Physiological / physiology
Adult
Electrocardiography / methods
Heart / innervation*,  physiology*
Heart Rate / physiology*
Hemostasis / physiology
Humans
Male
Middle Aged
Parasympathetic Nervous System / physiology*
Posture / physiology
Space Flight / methods
Supine Position
Weightlessness
Weightlessness Simulation / methods*

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


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