title: Time-variant parametric estimation of transient quadratic phase couplings between heart rate components in healthy neonates.
abstract: The heart rate variability (HRV) can be taken as an indicator of the coordination of the cardio-respiratory rhythms. Bispectral analysis using a direct (fast Fourier transform based) and time-invariant approach has shown the occurrence of a quadratic phase coupling (QPC) between a low-frequency (LF: 0.1 Hz) and a high-frequency (HF: 0.4-0.6 Hz) component of the HRV during quiet sleep in healthy neonates. The low-frequency component corresponds to the Mayer-Traube-Hering waves in blood pressure and the high-frequency component to the respiratory sinus arrhythmia (RSA). Time-variant, parametric estimation of the bispectrum provides the possibility of quantifying QPC in the time course. Therefore, the aim of this work was a parametric, time-variant bispectral analysis of the neonatal HRV in the same neonates used in the direct, time-invariant approach. For the first time rhythms in the time course of QPC between the HF component and the LF component could be shown in the neonatal HRV.
authors.affiliation: Institute of Medical Statistics, Computer Sciences and Documentation, Medical Faculty of the Friedrich Schiller University Jena, Bachstr. 18, 07740 Jena, Germany. iks@imsid.uni-jena.de
authors.forename: K
authors.initials: K
authors.lastname: Schwab
authors.forename: M
authors.initials: M
authors.lastname: Eiselt
authors.forename: P
authors.initials: P
authors.lastname: Putsche
authors.forename: M
authors.initials: M
authors.lastname: Helbig
authors.forename: H
authors.initials: H
authors.lastname: Witte
mesh_terms: D001146:Arrhythmia, Sinus / Q000503:physiopathology; D001794:Blood Pressure / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D012890:Sleep / Q000502:physiology; D013997:Time Factors