Comparison of techniques to correct artifacts and to RR interval selection for the 3 heart rate analysis groups. (A and D) PTS group. (B and E) PAS group. (C and F), ARA group. Data expressed as median, interquartile interval, maximum and minimum. RRi, RR intervals; DEL, exclusion; PRV, substitution by the average of previous data; ADJ, interpolation of adjacent data; LIN, linear interpolation; POL, polynomial interpolation; UNC, uncorrected data; 256 pts, 256 points; 5 min, five minutes. *Kruskal–Wallis test followed by Dunn's post hoc (p < 0.05). **Mann–Whitney test (p < 0.001).