VLF LF HF Baseline 2.75 ± 2.11 2.58 ± 2.23 0.56 ± 0.53 HUT 2.50 ± 2.91 3.65 ± 3.08 0.83 ± 1.04 6-cycle 1.13 ± 1.72 § 6.81 ± 7.33* 0.30 ± 0.22* 30-cycle 0.92 ± 0.82 § 1.42 ± 2.09* 1.25 ± 1.93

*p<0.05 compared with baseline; § means p<0.01 compared with baseline. The present form is (mean ± standard deviation). VLF denotes very low frequency band (0.01-0.04Hz); LF denotes low frequency band (0.04-0.15Hz); HF denotes high frequency band (0.15-0.4Hz); HUT denotes head-up tilt; 6-cycle denotes paced respiration with 6 cycles per minute; 30-cycle denotes paced respiration with 30 cycles per minute.

Table 1: Spectral analysis of conventional short-term blood pressure variability (BPV).