Document Detail

The independently fractal nature of respiration and heart rate during exercise under normobaric and hyperbaric conditions.
MedLine Citation:
PMID:  15705537     Owner:  NLM     Status:  MEDLINE    
To test the hypothesis that the fractal character of breathing and heart rate are independent, inter-breath intervals (IBI) and R-R intervals (RRI) were measured during rest and two levels of exercise at 1 and 2.8 ATA in a hyperbaric chamber in 18 male and female subjects (ages 19-74 years). Both RRI and IBI showed fractal properties. Fractal dimensions (D) for IBI were (mean +/- S.D.) 1.33 +/- 0.11, 1.29 +/- 0.12, 1.19 +/- 0.16 (rest, light and heavy exercise at 1ATA); 1.33 +/- 0.13, 1.25 +/- 0.13, 1.18 +/- 0.14 (same conditions at 2.8 ATA). Corresponding D for RRI were 1.19 +/- 0.11, 1.05 +/- 0.07 and 1.02 +/- 0.05 (1ATA); 1.20 +/- 0.10, 1.03 +/- 0.04 and 1.01 +/- 0.02 (2.8 ATA). The fractal dimension of each variable decreased with exercise and was unaffected by hyperbaric exposure. These two systems were not cross-correlated under any of the six conditions. During rest and light and moderate exercise at 1 and 2.8 ATA the results are consistent with heart rate variability and breathing rate variability being mutually independent of one another.
Bruce J West; Lori A Griffin; Heather J Frederick; Richard E Moon
Related Documents :
3094567 - An end-tidal sampler for use with slow response analysers during anaesthesia.
16247007 - Breath sulfides and pulmonary function in cystic fibrosis.
14979497 - Detection of expiratory flow limitation in copd using the forced oscillation technique.
24832977 - Vitamin d status and v[combining dot above]o2peak during a skate treadmill graded exerc...
6119937 - Clinical relevance of intrinsic sympathomimetic activity of beta blockers.
23971997 - Promoting exercise in patients with depression: lessons learned from a brief educationa...
Publication Detail:
Type:  Comparative Study; Journal Article    
Journal Detail:
Title:  Respiratory physiology & neurobiology     Volume:  145     ISSN:  1569-9048     ISO Abbreviation:  Respir Physiol Neurobiol     Publication Date:  2005 Feb 
Date Detail:
Created Date:  2005-02-11     Completed Date:  2005-05-02     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  101140022     Medline TA:  Respir Physiol Neurobiol     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  219-33     Citation Subset:  IM    
Mathematics Division, Army Research Office, Research Triangle Park, NC, and Physics Department, Duke University, Durham, NC, USA.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Atmospheric Pressure
Cross-Over Studies
Electrocardiography / methods
Exercise / physiology*
Heart Rate / physiology*
Hyperbaric Oxygenation*
Middle Aged
Models, Statistical
Nonlinear Dynamics
Oxygen Consumption
Physical Endurance
Rest / physiology
Time Factors

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

Previous Document:  The effect of sustained heavy exercise on the development of pulmonary edema in trained male cyclist...
Next Document:  Ventilatory acclimatization in awake guinea pigs raised at high altitude.