TABLE 3.

Changes in variability and asymmetry of heartbeat interval (RR) and systolic, diastolic, and pulse blood pressure (sBP, dBP, and PP, respectively) recorded in the vasovagal female group. Comparison between the supine (S), initial part of tilt (T1), and pre-syncope phase (T2) of HUTT conducted on biosignal variability measures—beat-to-beat and slow variability (SD1 and SD2) and its asymmetry indices: Guzik’s Index (GI), slow-term Guzik’s Index (GI_S), and Porta’s Index (PI).

Descriptor	Friedman’s p	Post-hoc p a
		S1–T1	S1–T2	T1–T2
RR
Mean	< 0.001	0.001	0.001	0.001
SD1	< 0.001	0.001	0.001	0.001
SD2	0.001	0.938	0.064	0.023
PI	0.7788	1.000	1.000	1.000
GI	0.3679	0.734	0.970	0.970
GIS	0.6456	1.000	1.000	1.000
sBP
Mean	< 0.001	0.002	0.485	0.003
SD1	0.087	0.970	0.970	0.422
SD2	0.047	0.109	0.149	0.149
PI	0.087	0.698	0.096	0.096
GI	0.829	1.000	1.000	1.000
GIS	0.444	0.776	0.133	0.109
dBP
Mean	< 0.001	0.001	0.083	0.002
SD1	0.105	0.816	0.533	0.084
SD2	0.185	0.149	0.073	0.856
PI	0.829	0.375	0.375	0.177
GI	0.047	0.512	0.512	0.856
GIS	0.087	0.979	0.049	0.027
PP
Mean PP	0.099	0.157	0.157	0.660
SD1	0.087	0.313	0.177	0.177
SD2	0.002	0.149	0.623	0.017
PI	0.269	0.673	0.673	0.673
GI	0.443	0.940	0.940	0.940
GIS	0.779	0.734	1.000	0.734

^a Holm’s correction.