Spontaneous and forced non-linear oscillations in heart period: role of the sino-atrial node.
The aim of this study is to investigate whether and to which extent the non-linearity of the sino-atrial node contributes to the complex interactions between autonomic control and heart period. A non-linear model of the autonomic control on the sino-atrial node has been analyzed under particular experimental conditions: the autonomic nervous system was forced to act at established frequencies, by a controlled breathing procedure and a non-invasive periodic modulation of carotid baroreceptors. We quantify the non-linear coupling between the stimuli and both the experimental and the simulated heart period fluctuations by using the recurrence plot quantification analysis. Our results show that the non-linear interaction between external stimuli and heart period fluctuations is due to a certain extent to the non-linear features of the sino-atrial node.
Censi
F
F
Biomedical Engineering Laboratory, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy. censi@dis.uniromal.it
Calcagnini
G
G
Bartolini
P
P
Bruni
C
C
Cerutti
S
S
D055592:Biophysical Phenomena; D001703:Biophysics; D004594:Electrophysiology; D006321:Heart / Q000502:physiology*; D006801:Humans; D015233:Models, Statistical; D009206:Myocardium / Q000473:pathology*; D009991:Oscillometry; D012849:Sinoatrial Node / Q000473:pathology* / Q000502:physiology