Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series

Multifractal properties of electrocardiographic inter-beat (RR) time-series offer insight into its long-term correlation structure, independently of RR variability. Here we quantify multifractal characteristics of RR data during 24-hour diurnal-nocturnal activity in healthy participants. We tested t...

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Main Authors: Michael James Lewis, Melitta A McNarry
Format: Article
Language:English
Published: Frontiers Media S.A. 2013-05-01
Series:Frontiers in Physiology
Subjects:
Online Access:http://journal.frontiersin.org/Journal/10.3389/fphys.2013.00100/full
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author Michael James Lewis
Melitta A McNarry
author_facet Michael James Lewis
Melitta A McNarry
author_sort Michael James Lewis
collection DOAJ
description Multifractal properties of electrocardiographic inter-beat (RR) time-series offer insight into its long-term correlation structure, independently of RR variability. Here we quantify multifractal characteristics of RR data during 24-hour diurnal-nocturnal activity in healthy participants. We tested the hypotheses that (1) age, gender and aerobic fitness influence RR multifractal properties, and that (2) these are influenced by circadian variation.Seventy adults (39 males) aged 19-58 years and of various fitness levels were monitored using 24-hour ECG. Participants were dichotomised by median age and fitness for sub-group analysis. Gender and fitness were independent of age (p=0.1, p>0.5). Younger/older group ages were substantially different (p<0.0005) and were independent of gender and fitness. Multifractality was quantified using the probability spectrum of Hölder exponents (h), from which modal h (h*) and the full-width and half-widths at half-maximum measures (FWHM, HWHM+ and HWHM-) were derived. FWHM decreased (p=0.004) and h* increased (p=0.011) in older people, indicating diminished long-range RR correlations and weaker anti-persistent behavior. Anti-persistent correlation (h*) was strongest in the youngest/fittest individuals and weakest in the oldest/least fit individuals (p=0.015). Long-range correlation (HWHM+/FWHM) was strongest in the fittest males and weakest in the least fit females (p=0.007-0.033).Multifractal RR characteristics in our healthy participants showed strong age-dependence with diminished long-range anti-persistent correlation in older people. Circadian variation of these characteristics was influenced by fitness and gender: fitter males and females of all ages had the greatest degree of multifractality or long-range order. Multifractal characterisation appears to be a useful method for exploring the physiological basis of long-term correlation structure in RR time-series as well as the benefits thereon of physical fitness training.
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spelling doaj.art-152c44a2b5b648bea170291bc007def72022-12-21T19:26:46ZengFrontiers Media S.A.Frontiers in Physiology1664-042X2013-05-01410.3389/fphys.2013.0010048524Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-SeriesMichael James Lewis0Melitta A McNarry1Swansea UniversitySwansea UniversityMultifractal properties of electrocardiographic inter-beat (RR) time-series offer insight into its long-term correlation structure, independently of RR variability. Here we quantify multifractal characteristics of RR data during 24-hour diurnal-nocturnal activity in healthy participants. We tested the hypotheses that (1) age, gender and aerobic fitness influence RR multifractal properties, and that (2) these are influenced by circadian variation.Seventy adults (39 males) aged 19-58 years and of various fitness levels were monitored using 24-hour ECG. Participants were dichotomised by median age and fitness for sub-group analysis. Gender and fitness were independent of age (p=0.1, p>0.5). Younger/older group ages were substantially different (p<0.0005) and were independent of gender and fitness. Multifractality was quantified using the probability spectrum of Hölder exponents (h), from which modal h (h*) and the full-width and half-widths at half-maximum measures (FWHM, HWHM+ and HWHM-) were derived. FWHM decreased (p=0.004) and h* increased (p=0.011) in older people, indicating diminished long-range RR correlations and weaker anti-persistent behavior. Anti-persistent correlation (h*) was strongest in the youngest/fittest individuals and weakest in the oldest/least fit individuals (p=0.015). Long-range correlation (HWHM+/FWHM) was strongest in the fittest males and weakest in the least fit females (p=0.007-0.033).Multifractal RR characteristics in our healthy participants showed strong age-dependence with diminished long-range anti-persistent correlation in older people. Circadian variation of these characteristics was influenced by fitness and gender: fitter males and females of all ages had the greatest degree of multifractality or long-range order. Multifractal characterisation appears to be a useful method for exploring the physiological basis of long-term correlation structure in RR time-series as well as the benefits thereon of physical fitness training.http://journal.frontiersin.org/Journal/10.3389/fphys.2013.00100/fullExerciseHeart RateAgeingmultifractalfitnessECG analysis
spellingShingle Michael James Lewis
Melitta A McNarry
Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series
Frontiers in Physiology
Exercise
Heart Rate
Ageing
multifractal
fitness
ECG analysis
title Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series
title_full Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series
title_fullStr Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series
title_full_unstemmed Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series
title_short Influence of Age and Aerobic Fitness on the Multifractal Characteristics of Electrocardiographic RR Time-Series
title_sort influence of age and aerobic fitness on the multifractal characteristics of electrocardiographic rr time series
topic Exercise
Heart Rate
Ageing
multifractal
fitness
ECG analysis
url http://journal.frontiersin.org/Journal/10.3389/fphys.2013.00100/full
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