Table 1.

Comparison of pulse rate variability (PRV) and heart rate variability (HRV)

	Supine		Sitting		Signal (PRV vs HRV)		Signal × posture
	PRV*	HRV	PRV*	HRV	F(1,42)	P	F(1,42)	P
Mean interval, ms	889 ± 64	880 ± 68	842 ± 64	843 ± 68	0.04	0.8	0.04	0.8
LF power, ln (ms2)	6.9 ± 0.3	6.2 ± 0.4	6.9 ± 0.3	6.5 ± 0.4	8.89	0.004	0.4	0.5
HF power, ln (ms2)	6.9 ± 0.4	5.9 ± 0.5	6.7 ± 0.4	5.7 ± 0.5	13.84	0.0006	0.01	0.9
LF/HF	1.1 ± 0.2	1.6 ± 0.3	1.4 ± 0.2	2.3 ± 0.3	13.97	0.0006	0.71	0.4

HF high-frequency component, LF low-frequency component

*Average over four sites

Data are least-square mean ± SE