Behavioral-independent features of complex heartbeat dynamics.
We test whether the complexity of the cardiac interbeat interval time series is simply a consequence of the wide range of scales characterizing human behavior, especially physical activity, by analyzing data taken from healthy adult subjects under three conditions with controls: (i) a "constant routine" protocol where physical activity and postural changes are kept to a minimum, (ii) sympathetic blockade, and (iii) parasympathetic blockade. We find that when fluctuations in physical activity and other behavioral modifiers are minimized, a remarkable level of complexity of heartbeat dynamics remains, while for neuroautonomic blockade the multifractal complexity decreases.
Nunes Amaral
L A
LA
Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215, USA. amaral@buphy.bu.edu
Ivanov
P C
PC
Aoyagi
N
N
Hidaka
I
I
Tomono
S
S
Goldberger
A L
AL
Stanley
H E
HE
Yamamoto
Y
Y
D000203:Activities of Daily Living; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000328:Adult; D001285:Atropine / Q000494:pharmacology; D005260:Female; D017709:Fractals; D006321:Heart / Q000187:drug effects / Q000294:innervation / Q000502:physiology*; D006801:Humans; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D010275:Parasympathetic Nervous System / Q000187:drug effects / Q000502:physiology; D010276:Parasympatholytics / Q000494:pharmacology; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology
D000319:Adrenergic beta-Antagonists; D010276:Parasympatholytics; D001285:Atropine; D008790:Metoprolol