Name
Title | ||
|---|---|---|
Operation Everest II: an indication of deterministic chaos in human heart rate variability at simulated extreme altitude. |
Abstract | ||
|---|---|---|
It has been shown that fluctuation of human heartbeat intervals (heart rate variability, HRV) reflects variations in autonomic nervous system activity. We studied HRV at simulated altitudes of over 6000 m from Holter electrocardiograms recorded during the Operation Everest II study (Houston et al. 1987). Stationary, approximately 30-min segments of HRV data from six subjects at sea level and over 6000 m were supplied to (1) spectral analysis to evaluate sympathetic and parasympathetic nervous system (SNS, PNS) activity, (2) the analysis of Poincaré section of the phase space trajectory reconstructed on a delayed coordinate system to evaluate whether there was fluctuation with deterministic dynamics, (3) the estimation of the correlation dimension to evaluate a static property of putative attractors, and (4) the analysis of nonlinear predictability of HRV time series which could reflect a dynamic property of the attractor. Unlike HRV at sea level, the recordings at over 6000 m showed a strong periodicity (period of about 20 s) with small cycle-to-cycle perturbation. When this perturbation was expressed on a Poincaré section, it seemed to be likely that the perturbation itself obeyed a deterministic law. The correlation dimensions of these recordings showed low dimensional values (3.5 +/- 0.4, mean +/- SD), whereas those of the isospectral surrogates showed significantly (P < 0.05) higher values (5.3 +/- 0.5) with embedding dimensions of 5.6 +/- 0.9.(ABSTRACT TRUNCATED AT 250 WORDS) |
Year | DOI | Venue |
|---|---|---|
1993 | 10.1007/BF00198960 | Biological Cybernetics |
Keywords | Field | DocType |
Heart Rate Variability,Correlation Dimension,Surrogate Data,Autonomic Nervous System Activity,Simulated Altitude | Attractor,Heartbeat,Effects of high altitude on humans,Telecommunications,Autonomic nervous system,Heart rate variability,Control theory,Mathematical analysis,Correlation dimension,Heart rate,Surrogate data,Mathematics | Journal |
Volume | Issue | ISSN |
69 | 3 | 0340-1200 |
Citations | PageRank | References |
1 | 0.65 | 1 |
Authors | ||
7 | ||
Name | Order | Citations | PageRank |
|---|---|---|---|
| Yoshiharu Yamamoto | 1 | 42 | 12.53 |
| R L Hughson | 2 | 14 | 5.33 |
| J R Sutton | 3 | 1 | 2.00 |
| C S Houston | 4 | 1 | 0.65 |
| A Cymerman | 5 | 1 | 0.65 |
| E L Fallen | 6 | 1 | 0.65 |
| Markad V. Kamath | 7 | 22 | 4.11 |