TY - JOUR
T1 - Circadian rhythmic fractal scaling of heart rate variability in health and coronary artery disease
AU - Otsuka, Kuntaki
AU - Cornelissen-Guillaume, Germaine G
AU - Halberg, Franz
PY - 1997
Y1 - 1997
N2 - Background: In clinical cardiology, heart rate variability is a putative index of autonomic cardiovascular function. Signs of reduced vagal activity are not only associated with an enhanced risk of sudden cardiac death, but such impaired heart rate variability became a new predictor of sudden cardiac death and other mortality in patients with a variety of diseased states. Hypothesis: It is postulated (1) that the time structure (chronome) of heart rate variability in clinical health includes a circadian rhythm and deterministic chaos, the latter gauged by the correlation dimension of RR intervals; and (2) that this chronome is altered in patients with coronary artery disease (CAD). Methods: From 24-h Holter records of 11 healthy controls and 10 patients with CAD, 500-s sections around 02:00,06:00, 10:00, 14:00, 18:00 and 22:00 hours were analyzed for smoothed RR intervals sampled at 4 Hz. Correlation integrals were estimated for embedding dimensions from 1 to 20 with a 1.0-s time lag, using an algorithm modified from Grassberger and Procaccia. The Wilcoxon signed-rank test compares circadian end points assessed by cosinor between the CAD patients and age-matched controls. Results: A circadian rhythm characterizes the correlation dimension of healthy subjects peaking during the night (p< 0.005). Patients with CAD have a lowered correlation dimension (p<0.05) and an altered circadian variation which re quires the consideration of an approximately 12-h (circasemidian) component. Conclusion: The results demonstrate the sensitivity of circadian rhythms for the detection of disease. A partial 24- to 12-h (circadian-to- circasemidian) frequency multiplication (or partial variance transposition) in CAD of the correlation dimension, apart from being a potential clue to the etiology of the disease, adds a new feature to a chronocardiology combining, with the fractal scaling, an assessment of circadian and circasemidian components as measures of predictable variability to be tested for rise in diagnosis, prognosis, and as putative guides to treatment timing.
AB - Background: In clinical cardiology, heart rate variability is a putative index of autonomic cardiovascular function. Signs of reduced vagal activity are not only associated with an enhanced risk of sudden cardiac death, but such impaired heart rate variability became a new predictor of sudden cardiac death and other mortality in patients with a variety of diseased states. Hypothesis: It is postulated (1) that the time structure (chronome) of heart rate variability in clinical health includes a circadian rhythm and deterministic chaos, the latter gauged by the correlation dimension of RR intervals; and (2) that this chronome is altered in patients with coronary artery disease (CAD). Methods: From 24-h Holter records of 11 healthy controls and 10 patients with CAD, 500-s sections around 02:00,06:00, 10:00, 14:00, 18:00 and 22:00 hours were analyzed for smoothed RR intervals sampled at 4 Hz. Correlation integrals were estimated for embedding dimensions from 1 to 20 with a 1.0-s time lag, using an algorithm modified from Grassberger and Procaccia. The Wilcoxon signed-rank test compares circadian end points assessed by cosinor between the CAD patients and age-matched controls. Results: A circadian rhythm characterizes the correlation dimension of healthy subjects peaking during the night (p< 0.005). Patients with CAD have a lowered correlation dimension (p<0.05) and an altered circadian variation which re quires the consideration of an approximately 12-h (circasemidian) component. Conclusion: The results demonstrate the sensitivity of circadian rhythms for the detection of disease. A partial 24- to 12-h (circadian-to- circasemidian) frequency multiplication (or partial variance transposition) in CAD of the correlation dimension, apart from being a potential clue to the etiology of the disease, adds a new feature to a chronocardiology combining, with the fractal scaling, an assessment of circadian and circasemidian components as measures of predictable variability to be tested for rise in diagnosis, prognosis, and as putative guides to treatment timing.
KW - Chronome
KW - Circadian
KW - Circasemidian
KW - Clinical health
KW - Coronary artery disease
KW - Correlation dimension
KW - Heart rate variability
KW - Rhythm
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U2 - 10.1002/clc.4960200710
DO - 10.1002/clc.4960200710
M3 - Article
C2 - 9220180
AN - SCOPUS:1842378596
SN - 0160-9289
VL - 20
SP - 631
EP - 638
JO - Clinical Cardiology
JF - Clinical Cardiology
IS - 7
ER -