title: Effect of considering constant variance time-frequency autoregressive models for HRV analysis.
abstract: Time-varying autoregressive modeling may consider the driving noise variance as a constant. In this work, the properties of the autoregressive driving noise variance of heart rate variability, with different stationary physiological conditions (resting in supine and sitting; exercise) are obtained. The effect of constant variance consideration for ramp exercise and recovery (a nonstationary condition) is also evaluated by the comparison of the time-varying absolute spectral parameters obtained by parametric estimation, allowing or not the modeling of time-varying noise variance, and a non-parametric time-frequency analysis. The driving noise variance presented a direct non-linear relationship with the heart period for the stationary maneuvers (r=0.91), while for the nonstationary condition, the use of a constant driving noise resulted in bias for the estimation of heart rate variability spectral parameters. A time-varying driving noise variance should be considered.
authors.affiliation: Dept. de Ciencias de la Salud, Univ. Autonoma Metropolitana Iztapalapa, Mexico City, Mexico. mjgg@xanum.uam.mx
authors.forename: Mercedes J
authors.initials: MJ
authors.lastname: Gaitán-Gonzalez
authors.forename: Salvador
authors.initials: S
authors.lastname: Carrasco-Sosa
authors.forename: Ramón
authors.initials: R
authors.lastname: González-Camarena
authors.forename: Oscar
authors.initials: O
authors.lastname: Yanez-Suarez
mesh_terms: D000328:Adult; D000465:Algorithms; D003198:Computer Simulation; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008955:Models, Cardiovascular; D015233:Models, Statistical; D012044:Regression Analysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity