The Fractal Structure of Cardiovascular Beat-To-Beat Series Described over a Broad Range of Scales: Differences between Blood Pressure and Heart Rate, and the Effect of Gender

Abstract

The fractal characteristics of heart rate variability are usually assessed by estimating short- and long-term scale coefficients, alpha1 and alpha2, by detrended fluctuation analysis. Recently we extended this approach introducing a temporal spectrum of scale coefficients, alpha(tau), that describes the deviations of self-similarity from the bi-fractal model at each scale tau. Until now relatively short recordings were considered and alpha(tau) was characterized only for scales tau