Short- and long-term joint symbolic dynamics of heart rate and blood pressure in dilated cardiomyopathy.
Autonomic cardiovascular control involves complex interactions of heart rate and blood pressure. In patients with dilated cardiomyopathy (DCM), this control is impaired and parameters for its quantification might be of prognostic importance. In this paper, we introduce methods based on joint symbolic dynamics (JSD) for the enhanced analysis of heart rate and blood pressure interactions. To assess the coarse-grained dynamics beat-to-beat changes of heart rate and blood pressure are encoded in symbol strings. Subsequently, the distribution properties of short symbol sequences (words) as well as the scaling properties of the whole symbol string are assessed. The comparison of joint symbolic heart rate and blood pressure dynamics in DCM (n = 75) with those in healthy controls (n = 75) showed significant changes. Both, the distribution of words and the scaling properties indicate a loss in heart rate dynamics associated with blood pressure regulation in DCM. In conclusion, the analyses of short- and long-term JSDs provide insights into complex physiological heart rate and blood pressure interactions and furthermore reveal patho-physiological cardiovascular control in DCM.
Baumert
Mathias
M
Department of Medical Engineering, University of Applied Sciences Jena, 07745 Jena, Germany.
Baier
Vico
V
Truebner
Sandra
S
Schirdewan
Alexander
A
Voss
Andreas
A
D001794:Blood Pressure; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis* / Q000503:physiopathology*; D003198:Computer Simulation; D003627:Data Interpretation, Statistical; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D006339:Heart Rate; D006801:Humans; D008875:Middle Aged; D008955:Models, Cardiovascular; D015233:Models, Statistical; D013223:Statistics as Topic; D013997:Time Factors