This review describes nonlinear methods based on chaos, fractality, and complexity used to assess heart-rate dynamics, along with their most notable applications.
This review summarizes the application of nonlinear mathematical methods for analyzing heart-rate variability, highlighting their potential to expand knowledge of cardiovascular dynamics despite currently being far from clinical practice.
The heart-rate dynamics are one of the most analyzed physiological interactions. Many mathematical methods were proposed to evaluate heart-rate variability. These methods have been successfully applied in research to expand knowledge concerning the cardiovascular dynamics in healthy as well as in pathological conditions. Notwithstanding, they are still far from clinical practice. In this paper, we aim to review the nonlinear methods most used to assess heart-rate dynamics. We focused on methods based on concepts of chaos, fractality, and complexity: Poincaré plot, recurrence plot analysis, fractal dimension (and the correlation dimension), detrended fluctuation analysis, Hurst exponent, Lyapunov exponent entropies (Shannon, conditional, approximate, sample entropy, and multiscale entropy), and symbolic dynamics. We present the description of the methods along with their most notable applications.
Henriques et al. (2020) conducted a review in Heart-rate dynamics and variability. Nonlinear methods (chaos, fractality, and complexity) was evaluated. This review describes nonlinear methods based on chaos, fractality, and complexity used to assess heart-rate dynamics, along with their most notable applications.