TY - JOUR
T1 - Toward chronocardiologic and chronomic insights
T2 - Dynamics of heart rate associated with head-up tilting
AU - Kubo, Yutaka
AU - Murakami, Shogo
AU - Matsuoka, Osamu
AU - Hotta, Norihiro
AU - Oinuma, Sachiko
AU - Shinagawa, Makoto
AU - Omori, Keigi
AU - Nunoda, Shinichi
AU - Otsuka, Kuniaki
AU - Ohkawa, Shin Ichiro
AU - Cornelissen-Guillaume, Germaine G
AU - Halberg, Franz
PY - 2003/10
Y1 - 2003/10
N2 - As a step towards investigating the chronome (i.e. the inferential endpoints of chaos, trends and rhythms) of heart rate (HR) variability (HRV), we investigated whether the fractality or complexity of HRV is affected by a head-up tilting (HUT) test in the morning after an overnight fast. Spectral and non-linear analyses of HR were performed on data gathered during an 80° passive HUT test in 15 men and 28 women 32.8 ± 11.5 years of age. The non-linear endpoints included the scaling exponents α1 (<11 beats) and α2 (>11 beats), which indicate fractal properties, calculated with detrended fluctuation analysis, and the approximate entropy (ApEn), a measure of overall complexity. Passive HUT increased α1 (from 0.986 ± 0.217 to 1.370 ± 0.185; P = 0.0001), but did not alter α2 (from 0.925 ± 0.110 to 0.958 ± 0.130; P = 0.19). A slight but statistically significant decrease in ApEn was seen during HUT (from 1.114 ± 0.131 to 1.013 ± 0.197; P = 0.002). In the tilt-up position, there was a statistically significant negative correlation between α1 and ApEn (r = -0.490; P < 0.05). In both the supine and the tilt-up position, α 1 was correlated weakly with HF (r = -0.343 and r = -0.322, respectively), and strongly with LF/HF (r = 0.557 and r = 0.795), respectively. There was also a negative correlation between ApEn and LF/HF (r = -0.406 and r = -0.357, respectively). α2 did not correlate with any spectral or non-linear measures of HRV. Short-term fractal properties and complexity of HR were lowered with orthostatic stress. Alterations of the autonomic activities could be partly responsible for these changes and await extension of such studies to assess the broad spectral element of HRV, that includes, with components of ∼3.6 and ∼10.5 s, cycles with very much lower frequencies, along the scales of hours and even years, that critically modulate the mislabeled (only relatively high- and low-frequency) components in the range of seconds or minutes.
AB - As a step towards investigating the chronome (i.e. the inferential endpoints of chaos, trends and rhythms) of heart rate (HR) variability (HRV), we investigated whether the fractality or complexity of HRV is affected by a head-up tilting (HUT) test in the morning after an overnight fast. Spectral and non-linear analyses of HR were performed on data gathered during an 80° passive HUT test in 15 men and 28 women 32.8 ± 11.5 years of age. The non-linear endpoints included the scaling exponents α1 (<11 beats) and α2 (>11 beats), which indicate fractal properties, calculated with detrended fluctuation analysis, and the approximate entropy (ApEn), a measure of overall complexity. Passive HUT increased α1 (from 0.986 ± 0.217 to 1.370 ± 0.185; P = 0.0001), but did not alter α2 (from 0.925 ± 0.110 to 0.958 ± 0.130; P = 0.19). A slight but statistically significant decrease in ApEn was seen during HUT (from 1.114 ± 0.131 to 1.013 ± 0.197; P = 0.002). In the tilt-up position, there was a statistically significant negative correlation between α1 and ApEn (r = -0.490; P < 0.05). In both the supine and the tilt-up position, α 1 was correlated weakly with HF (r = -0.343 and r = -0.322, respectively), and strongly with LF/HF (r = 0.557 and r = 0.795), respectively. There was also a negative correlation between ApEn and LF/HF (r = -0.406 and r = -0.357, respectively). α2 did not correlate with any spectral or non-linear measures of HRV. Short-term fractal properties and complexity of HR were lowered with orthostatic stress. Alterations of the autonomic activities could be partly responsible for these changes and await extension of such studies to assess the broad spectral element of HRV, that includes, with components of ∼3.6 and ∼10.5 s, cycles with very much lower frequencies, along the scales of hours and even years, that critically modulate the mislabeled (only relatively high- and low-frequency) components in the range of seconds or minutes.
KW - Fractals
KW - Head-up tilting
KW - Heart rate variability
KW - Non-linear analysis
UR - http://www.scopus.com/inward/record.url?scp=0142169339&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0142169339&partnerID=8YFLogxK
U2 - 10.1016/j.biopha.2003.08.014
DO - 10.1016/j.biopha.2003.08.014
M3 - Article
C2 - 14572686
AN - SCOPUS:0142169339
VL - 57
SP - 110
EP - 115
JO - Biomedicine and Pharmacotherapy
JF - Biomedicine and Pharmacotherapy
SN - 0753-3322
IS - SUPPL. 1
ER -