Table 2. Changes in time-domain features across six consecutive PVT blocks (x̄ ± s). Time-domain features Block 1 Block 2 Block 3 Block 4 Block 5 Block 6 Mean RR 779.82 ± 105.37 775.4 ± 98.24 774.14 ± 94.6 779.91 ± 92.84 780.01 ± 91.09 784.21 ± 90.75 SDNN 44.3 ± 17.62 45.06 ± 18.31 46.42 ± 19.57 46.38 ± 15.26 49.11 ± 18.92 47.51 ± 16.87 Mean HR 78.28 ± 10.16 78.53 ± 9.31 78.59 ± 9.07 77.96 ± 8.82 77.95 ± 8.95 77.49 ± 8.67 SDHR 4.58 ± 2.45 4.73 ± 2.6 4.95 ± 2.86 4.76 ± 1.78 5.16 ± 2.58 4.8 ± 2.02 HR Max-min 27.21 ± 8.25 28.9 ± 9.65 29.02 ± 8.1 29.65 ± 8.1 31.88 ± 13.58 30.21 ± 7.37 RMSSD 40.26 ± 23.77 38.76 ± 27.19 39.63 ± 28.49 39.16 ± 19.71 41.79 ± 27.43 40.07 ± 23.13 NN50 96.19 ± 81.65 81.41 ± 65.68 81.31 ± 67.08 84.62 ± 66.54 83.82 ± 68.01 82.37 ± 61.77 pNN50 18.91 ± 16.54 15.67 ± 13.58 15.6 ± 13.8 16.3 ± 13.76 16.12 ± 14.05 16.2 ± 13.08 RR tri index 11.8 ± 3.86 11.56 ± 3.39 12.14 ± 3.82 12.12 ± 3.44 12.28 ± 3.59 11.96 ± 3.22 TINN 234.24 ± 102.34 244.75 ± 125.05 245.86 ± 123.6 250.46 ± 104.4 272.04 ± 148.74 254.37 ± 132.94