title: Complexity analysis of electrocardiographic signals.
abstract: Two types of electrocardiographic data series were investigated using appropriate tests based on a selection of semi-quantitative analysis algorithms. Distribution histograms, power spectra, auto-correlation functions, state-space portraits, Lyapunov exponents and wavelet transformations were applied to electrocardiograms of normal and stressed subjects. Statistical analysis using the Student's t-test revealed significant and non-significant alterations in stress-loaded cases compared to normal ones. Higher levels of adrenaline may account for a more complex dynamics (deterministic chaos) revealed in the stressed subjects.
authors.affiliation: University Al I Cuza, Faculty of Biology, 20A Bd. Carol I, Iasi, Romania. ineacsu@uaic.ro
authors.forename: I
authors.initials: I
authors.lastname: Neacsu
authors.forename: D E
authors.initials: DE
authors.lastname: Creanga
authors.forename: F M
authors.initials: FM
authors.lastname: Tufescu
mesh_terms: D000465:Algorithms; D004562:Electrocardiography / Q000379:methods*; D004837:Epinephrine / Q000378:metabolism; D017709:Fractals; D006321:Heart / Q000502:physiology; D006801:Humans; D015233:Models, Statistical; D009206:Myocardium / Q000473:pathology; D017711:Nonlinear Dynamics; D012815:Signal Processing, Computer-Assisted
chemical_list: D004837:Epinephrine