The independently fractal nature of respiration and heart rate during exercise under normobaric and hyperbaric conditions.

Published

Journal Article

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.

Full Text

Duke Authors

Cited Authors

  • West, BJ; Griffin, LA; Frederick, HJ; Moon, RE

Published Date

  • February 15, 2005

Published In

Volume / Issue

  • 145 / 2-3

Start / End Page

  • 219 - 233

PubMed ID

  • 15705537

Pubmed Central ID

  • 15705537

International Standard Serial Number (ISSN)

  • 1569-9048

Digital Object Identifier (DOI)

  • 10.1016/j.resp.2004.07.010

Language

  • eng

Conference Location

  • Netherlands