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

• Published in: Europhysics letters Vol. 48; no. 5; pp. 594 - 600
• Main Authors: Ivanov, P. Ch, Bunde, A, Amaral, L. A. N, Havlin, S, Fritsch-Yelle, J, Baevsky, R. M, Stanley, H. E, Goldberger, A. L
• Format: Journal Article
• Language: English
• Published: Legacy CDMS IOP Publishing 01.12.1999; EDP Sciences
• Subjects: 87.10.+e; 87.19.Hh; 87.19.Jj; Astronauts; Cardiovascular Physiological Phenomena; Heart Failure - physiopathology; Heart Rate - physiology; Humans; Life Sciences (General); Sleep - physiology; Space Flight; Wakefulness - physiology; Weightlessness; Human; Support, U.s. Gov't, Non-P.h.s; Support, Non-U.s. Gov't; Nasa Discipline Cardiopulmonary; Heart Rate/physiology; Comparative Study; Support, U.s. Gov't, P.h.s; Non-Nasa Center; Wakefulness/physiology; Heart Failure, Congestive/physiopathology; Weightlessness; Space Flight; Sleep/physiology; Flight Experiment; Nasa Center Jsc; Cardiovascular Physiology; Long Duration; Astronauts; Manned; Mir Project; NASA Discipline Cardiopulmonary; NASA Center JSC; Non-NASA Center
• ISSN: 0295-5075; 1286-4854
• DOI: 10.1209/epl/i1999-00525-0

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.