Table 2.

Linear methods of heart rate variability analyzed from the sample databases obtained from the selection of 256 highest stability points and the final 5 min of the recording for the 3 heart rate analysis groups i.e. the cardiac patient group (PTS group), the physically active group (PAS group), and the athletic group (ARA group).

	PTS group			PAS group			ARA group
	256 points	5 min	p	256 points	5 min	p	256 points	5 min	p
Time-domain
Mean RR (ms)	860 ± 240	860 ± 240	0.94	950 ± 260	950 ± 250	0.95	1100 ± 140	1100 ± 130	0.69
SDNN (ms)	16 ± 14	17 ± 13	0.39	34 ± 52	44 ± 50	0.63	50 ± 32	57 ± 21	0.51
RMSSD (ms)	15 ± 24	15 ± 23	0.97	27 ± 56	32 ± 52	0.77	40 ± 46	41 ± 45	0.95
pNN50 (%)	0.0 ± 7.5	0.1 ± 8.5	0.66	4.3 ± 25.0	9.4 ± 25.0	0.79	24 ± 41	25 ± 40	0.84
Triangular index	4.8 ± 3.7	5.1 ± 3.6	0.47	6.4 ± 7.0	9.0 ± 9.4	0.63	12.0 ± 9.0	16.0 ± 6.0	0.21
TINN (ms)	40 ± 64	58 ± 66	0.27	78 ± 140	88 ± 117	0.55	80 ± 150	95 ± 190	0.79
Frequency-domain
LF (ms2)	38 ± 126	50 ± 141	0.29	200 ± 949	320 ± 1140	0.76	530 ± 1530	810 ± 1680	0.84
HF (ms2)	57 ± 170	66 ± 131	0.99	250 ± 1171	270 ± 1036	0.80	490 ± 1440	440 ± 1390	0.65
Total power (ms2)	200 ± 481	230 ± 460	0.29	1200 ± 3580	1400 ± 3570	0.66	2900 ± 3900	3100 ± 4700	0.65
LF (u.n.)	45 ± 41	58 ± 34	0.20	42 ± 38	46 ± 44	0.99	45 ± 34	55 ± 35	0.79
HF (u.n.)	55 ± 41	41 ± 34	0.19	58 ± 37	54 ± 44	0.98	55 ± 34	45 ± 35	0.79
LF/HF ratio	0.83 ± 1.41	1.40 ± 1.83	0.21	0.72 ± 1.85	0.86 ± 2.33	0.98	0.81 ± 1.67	1.20 ± 2.02	0.82

PTS, patients with aortic stenosis; PAS, physically active subjects; ARA, amateur running athletes; SDNN, the standard deviation of all RRi; RMSSD, square root of the sum of squared RRi differences; pNN50, percent of RRi above 50 ms; TINN, triangular interpolation of the RRi histogram; LF, low-frequency; HF, high-frequency. Values expressed as median ± interquartile range.