Fig. 2

Comparison of the distribution of (a) average NN intervals (AVNN) values; (b) Standard Deviation of NN Intervals (SDNN); (c) Low/High Frequency Ratio (LF-HF); and (d) heart rate (HR) across different levels of arterial occlusion pressure (AOP) (40%, 80%, 100%, and 130%). * indicates significant differences in pairwise comparisons.