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Information scaling properties of heart rate variability
1Cardiovascular Research Group, University of Calgary, Calgary, Alberta, Canada T2N 4N1.
The American Journal of Physiology
|June 25, 1998
Summary
Human resting heart period sequences exhibit unique information scaling properties, differing significantly from chaotic or periodic controls. This suggests an events-based approach is key to understanding heart rate variability.
Area of Science:
- Physiology
- Complexity Science
- Information Theory
Background:
- Chaos detection methods often struggle to differentiate chaotic signals from correlated noise.
- Understanding the global organization of physiological signals like heart rate is crucial.
Purpose of the Study:
- To determine if human resting heart period sequences possess global properties characteristic of chaotic systems.
- To investigate the inherent global organization of heart period sequences by analyzing information content variation with scale.
Main Methods:
- Quantified information content scaling in 60-minute heart period sequences from 10 healthy volunteers.
- Compared scaling characteristics against periodic and chaotic control sequences.
- Analyzed nondeterministic components like tachycardic/bradycardic events and aperiodic fluctuations.
Main Results:
- Heart period sequences showed significantly different information scaling properties compared to controls, especially at coarser scales (p < 0.0005).
- Nondeterministic physiological events can mimic scaling properties observed in resting heart rate.
Conclusions:
- Human resting heart period sequences do not exhibit global properties solely characteristic of low-dimensional chaotic systems.
- Findings support an events-based approach for interpreting heart rate variability, integrating spectral, nonlinear, and lexical evidence.