Intraindividual analysis of instantaneous heart rate variability.
We examined the use and potential of quantifying instantaneous heart rate variability (HRV) using a joint time-frequency and time-domain methods. These new techniques are promising, because they provide tools to quantify nonstationary, beat-by-beat changes in HRV components, and are therefore flexible with respect to the design of experimental protocols. A smoothed pseudo-Wigner-Ville distribution (SPWVD) and a time-domain index using polynomial filtering produced fairly coherent estimates of band-specific HRV amplitudes, whereas SPWVD yielded additional information on the frequency characteristics of HRV. Instantaneous HRV appeared to have a complex and a frequency-specific relationship to cardiac activity and electrodermal activity, It is concluded that the time-frequency analysis of HRV is a very promising method for mapping transient changes in the frequency and amplitude characteristics of cardiac dynamics.
Kettunen
J
J
Department of Psychology, University of Helsinki, Finland. jokettunen@kihu.jyu.fi
Keltikangas-Järvinen
L
L
D000328:Adult; D001143:Arousal; D004562:Electrocardiography; D006339:Heart Rate; D006801:Humans; D007206:Individuality; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted