Table 2.

Intergroup comparison of parameters in a frequency domain analysis of heart-rate variability during orthostatic load (supine-1-standing-supine-2)

Spectral power	CAR	NCAR	p-value
Supine-1
Power LF, ms2	243.4±140.7	59.0±39.3	<0.0001
Power LF, ln(ms2)	5.3±0.6	3.7±1.0	<0.0001
Power HF, ms2	183.5±106.4	32.6±20.3	<0.0001
Power HF, ln(ms2)	5.1±0.6	3.2±0.8	<0.0001
Total power, ms2	426.9±233.8	91±53.9	<0.0001
Total power, ln(ms2)	5.9±0.5	4.3±0.7	<0.0001
LF/HF	1.4±0.6	2.2±1.8	0.0361
Standing
Power LF, ms2	259.1±145.4	51.7±39.9	<0.0001
Power LF, ln(ms2)	5.4±0.6	3.7±0.8	<0.0001
Power HF, ms2	93.4±42.4	21.2±19.5	<0.0001
Power HF, ln(ms2)	4.4±0.5	2.7±0.9	<0.0001
Total power, ms2	352.5±166.3	72.9±53.0	<0.0001
Total power, ln(ms2)	5.8±0.5	4.1±0.7	<0.0001
LF/HF	3.2±2.0	3.9±3.5	NS*
Supine-2
Power LF, ms2	224.3±118.2	55.8±28.6	<0.0001
Power LF, ln(ms2)	5.2±0.7	3.8±0.8	<0.0001
Power HF, ms2	208.5±98.5	43.5±26.4	<0.0001
Power HF, ln(ms2)	5.2±0.5	3.5±0.8	<0.0001
Total power, ms2	432.9±156.3	99.4±45.5	<0.0001
Total power, ln(ms2)	6.0±0.4	4.4±0.7	<0.0001
LF/HF	1.3±0.8	1.7±1.5	NS

Notes: Data are presented as mean ± standard deviation.

^*p>0.05.

Abbreviations: CAR, cardiac autonomic reactivity; HF, high frequency; LF, low frequency; NCAR, non-cardiac autonomic reactivity; NS, not significant.