Non-Linear Dynamics In Patients With Stable Angina Pectoris

We investigate the clinical and prognostic significance of fractal dimension and detrended fluctuation analysis by comparing the group of patients with stable angina pectoris without previous myocardial infarction with the group of age-matched healthy controls. The fractal dimension of the R-R series was determined using the rescaled range (R/S) analysis technique. To quantify fractal longe-range-correlation properties of heart rate variability, the detrended fluctuation analysis (DFA) technique was used. The heart rate variability was characterized by a scaling exponent $\alpha$, separately for short-term ($<$ 11 beats), and for long-term ($>$ 11 beats) time scales. The results of data sets show the existence of crossover phenomena between short-time scales. The short-term fractal scaling exponent was significantly lower in patients with stable angina pectoris.