The interaction between sympathetic and parasympathetic nerve activities at the level of sinus node play a dominant role in the magnitude and time course of heart rate fluctuations. The analysis of short-term heart rate variability provides measures of the response of the sinus node to autonomic neural control in different patho-physiological states of the cardiovascular system functioning. Diminished variability, as a result of an ANS control dysfunction is often attended by profound changes in dynamics that cannot be characterized by simple linear measures of the global variability. Our interest regards the predictability and nonlinearity of the heart rhythm and their relation with the state of neural control of the heart. In the present study, we analyze the nonlinear predictability of the RR interval time series in two different states of neural regulation: normal function and pharmacological blockade, by means of atropine and propanolol.
['Laura Cimponeriu', 'Anastassios Bezerianos']
Determinism and Nonlinearity of the Heart Rhythm