GLOSSARY OF TERMS USED IN TIME SERIES ANALYSIS OF CARDIOVASCULAR DATA

|LEVEL 0| |HOMEPAGE|

A measure of the fractal dimension of the time series.

May be computed by means of the method descibed by Grassberger and Procaccia. Correlation Dimension of heart rate has been shown to decrease with age, to be higher in female than in male subjects (Otzuka et al, 1997a), to have a circadian rhythm (Van Leuween et al., 1996) altered in patients with coronary artery disease (Otzuka et al, 1997b), to be lower during general anaesthesia (Zwiener et al., 1996) and to decrease before lethal arrhythmias (Skinner et al., 1993)

References:
Grassberger P, Procaccia I (1983) Measuring the strangeness of a strange attractor. Physica D, 9, 189-208.
Ganz RE, Lenz C.(1996) A program for the user-independent computation of the correlation dimension and the largest Lyapunov exponent of heart rate dynamics from small data sets. Comput Methods Programs Biomed.

Otsuka K et al. (1997a) Age, gender and fractal scaling in heart rate variability.Clin Sci
Otsuka K et al. (1997b) Circadian rhythmic fractal scaling of heart rate variability in health and coronary artery disease. Clin Cardiol.
Van Leeuwen P(1995) Circadian aspects of apparent correlation dimension in human heart rate dynamics.  Am J Physiol.
Storella RJ et al (1998)Approximate entropy and point correlation dimension of heart rate variability in healthy subjects. Integr Physiol Behav Sci.
Thayer JF, Moulden SA.(1997) Estimation of the correlation dimension of heart rate using surrogate data techniques.Biomed Sci Instrum.
 Zwiener U et al.(1996) Relations between parameters of spectral power densities and deterministic chaos of heart-rate variability  J Auton Nerv Syst.
Skinner JE et al (1993) A reduction in the correlation dimension of heartbeat intervals precedes imminent ventricular fibrillation in human subjects.  Am Heart J.