Europhys. Lett.
Volume 48, Number 5, December 1999
Page(s) 594 - 600
Section Interdisciplinary physics and related areas of science and technology
Published online 01 September 2002
DOI: 10.1209/epl/i1999-00525-0

Europhys. Lett, 48 (5), pp. 594-600 (1999)

Sleep-wake differences in scaling behavior of the human heartbeat: Analysis of terrestrial and long-term space flight data

P.Ch.Ivanov 1,2, A.Bunde 3, L.A.N.Amaral 1,2, S.Havlin 4, J.Fritsch-Yelle 5-1
R. M. Baevsky 6, H. E. Stanley 1 and A. L. Goldberger 2

1 Center for Polymer Studies and Department of Physics, Boston University
Boston, MA 02215, USA
2 CardiovascularDivision,HarvardMedicalSchool,BethIsraelDeaconessMedicalCenter
Boston, MA 02215, USA
3 Institute für Theoretische Physik III, Justus-Liebig-Universität - Giessen, Germany
4 Gonda Goldschmid Center and Department of Physics, Bar-Ilan University
Ramat Gan, Israel
5 Life Sciences Research Laboratories, Lyndon B. Johnson Space Center
Houston, TX 77058, USA
6 Institute of Biomedical Problems - Moscow, Russia

(received 31 May 1999; accepted in final form 23 September 1999)

PACS. 87.19Hh - Cardiac dynamics.
PACS. 87.19Jj - Circadian rhythms.
PACS. 87.10+e - Biological and medical physics: General theory and mathematical aspects.


We compare scaling properties of the cardiac dynamics during sleep and wake periods for healthy individuals, cosmonauts during orbital flight, and subjects with severe heart disease. For all three groups, we find a greater degree of anticorrelation in the heartbeat fluctuations during sleep compared to wake periods. The sleep-wake difference in the scaling exponents for the three groups is comparable to the difference between healthy and diseased individuals. The observed scaling differences are not accounted for simply by different levels of activity, but appear related to intrinsic changes in the neuroautonomic control of the heartbeat.


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