Figure 1From: Sensitivity of temporal heart rate variability in Poincaré plot to changes in parasympathetic nervous system activity Poincaré plots with similar SD 1 and SD 2 having different temporal dynamics. Two different RR interval time series of length N (N = 2000) with similar SD 1 and SD 2 values having different temporal dynamics (first 20 points) are shown in top and bottom panel.Back to article page