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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
4 Pt 2
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pubmed:dateCreated |
1996-12-16
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pubmed:abstractText |
We postulated that aging is associated with disruption in the fractallike long-range correlations that characterize healthy sinus rhythm cardiac interval dynamics. Ten young (21-34 yr) and 10 elderly (68-81 yr) rigorously screened healthy subjects underwent 120 min of continuous supine resting electrocardiographic recording. We analyzed the interbeat interval time series using standard time and frequency domain statistics and using a fractal measure, detrended fluctuation analysis, to quantify long-range correlation properties. In healthy young subjects, interbeat intervals demonstrated fractal scaling, with scaling exponents (alpha) from the fluctuation analysis close to a value of 1.0. In the group of healthy elderly subjects, the interbeat interval time series had two scaling regions. Over the short range, interbeat interval fluctuations resembled a random walk process (Brownian noise, alpha = 1.5), whereas over the longer range they resembled white noise (alpha = 0.5). Short (alpha s)- and long-range (alpha 1) scaling exponents were significantly different in the elderly subjects compared with young (alpha s = 1.12 +/- 0.19 vs. 0.90 +/- 0.14, respectively, P = 0.009; alpha 1 = 0.75 +/- 0.17 vs. 0.99 +/- 0.10, respectively, P = 0.002). The crossover behavior from one scaling region to another could be modeled as a first-order autoregressive process, which closely fit the data from four elderly subjects. This implies that a single characteristic time scale may be dominating heartbeat control in these subjects. The age-related loss of fractal organization in heartbeat dynamics may reflect the degradation of integrated physiological regulatory systems and may impair an individual's ability to adapt to stress.
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pubmed:grant | |
pubmed:keyword | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0002-9513
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
271
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
R1078-84
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8898003-Adult,
pubmed-meshheading:8898003-Aged,
pubmed-meshheading:8898003-Aged, 80 and over,
pubmed-meshheading:8898003-Aging,
pubmed-meshheading:8898003-Female,
pubmed-meshheading:8898003-Fractals,
pubmed-meshheading:8898003-Heart Rate,
pubmed-meshheading:8898003-Humans,
pubmed-meshheading:8898003-Male,
pubmed-meshheading:8898003-Models, Cardiovascular
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pubmed:year |
1996
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pubmed:articleTitle |
Age-related alterations in the fractal scaling of cardiac interbeat interval dynamics.
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pubmed:affiliation |
Hebrew Rehabilitation Center for Aged, Boston 02131, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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