Instantaneous changes in the heart rate variability during head-up tilt revealed by positive time-frequency distribution

S.I. Shah; V. Shusterman; B. Aysin; S. Flanigan; K.P. Anderson

doi:10.1109/TFSA.1998.721409

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Conference proceeding

Instantaneous changes in the heart rate variability during head-up tilt revealed by positive time-frequency distribution

S.I. Shah, V. Shusterman, B. Aysin, S. Flanigan and K.P. Anderson

Proceedings of the IEEE-SP International Symposium on Time-Frequency and Time-Scale Analysis (Cat. No.98TH8380), pp.253-256

1998

DOI: 10.1109/TFSA.1998.721409

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Abstract

Energy distribution of the heart rate variability signal is perturbed in patients with impaired cardiac function compared to normal subjects (Li et al., 1997). We hypothesized that the energy distribution reflects the changes in autonomic regulation that are not exposed by conventional methods estimating the power in the empirically defined frequency ranges. To test this hypothesis instantaneous power changes in the heart rate variability signal were computed between 0.0025 and 0.25 Hz in 20 patients undergoing head-up tilting. Positive time frequency distribution (TFD) was obtained by the method of minimum cross entropy (Loughlin et al., 1994) that satisfies the time and frequency marginals. The distribution of power was calculated by separating the total frequency range into seven scales. Significant changes in the mean spectral power and its distribution were observed in those patients who experienced symptoms compared to those who were asymptomatic. We conclude that the loss of spectral power and changes in the power distribution revealed by positive TFD can be useful for assessment of physiological adaptation and diagnosis of the disorders related to autonomic imbalance.

Distributed computing

Electrocardiography

Entropy

Frequency estimation

Heart rate variability

Magnetic recording

Medical diagnostic imaging

Power distribution

Testing

Time frequency analysis

Details

Title: Subtitle: Instantaneous changes in the heart rate variability during head-up tilt revealed by positive time-frequency distribution
Creators: S.I. Shah - University of Pittsburgh
V. Shusterman
B. Aysin
S. Flanigan
K.P. Anderson
Resource Type: Conference proceeding
Publication Details: Proceedings of the IEEE-SP International Symposium on Time-Frequency and Time-Scale Analysis (Cat. No.98TH8380), pp.253-256
Publisher: IEEE
DOI: 10.1109/TFSA.1998.721409
Language: English
Date published: 1998
Academic Unit: Cardiovascular Medicine; Internal Medicine
Record Identifier: 9984359934002771

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