Table 4

Power spectrum analysis in the supine and standing positions

RRSAPDAPMFV
Supine Standing Supine Standing Supine Standing Supine Standing
Control
Mean value906 (168)764 (169)132 (16)119 (14)67 (7)69 (7)49 (16)49 (13)
LF (ms2/Hz)455 (233)263 (128)4-150 6.3 (13)28 (24)4-150 1.69 (0.9)5.8 (3.5) 2.23 (1.0)4.7 (2.1)
HF (ms2/Hz)411 (342)71 (87) 1.9 (1.1)6.4 (3.2)4-150 0.49 (0.5)0.73 (0.5)1.28 (1.5)1.96 (2.2)
LFnu52 (13)78 (8.9)
HFnu47 (13)21 (8.8)
LF/HF1.13.71
Vasovagal syncope
Mean value901 (134)776 (164)136 (13)122 (20)61 (10)64 (11)54 (16)55 (9)
LF (ms2/Hz)466 (135)386 (131)4-150 9.9 (15)25 (11)4-150 4.02 (3)8.41 (5) 3.4 (2.02)7.6 (3.2)
HF (ms2/Hz)364 (121)85 (87) 2.7 (3.4)4.9 (3.4)0.73 (1)0.38 (0.31)2.25 (1.7)2.01 (2.3)
LFnu55 (25)81 (13)
HFnu43 (25)18 (14)
LF/HF1.24.5
Diabetes
Mean value920 (238)847 (277)135 (17)118 (20)64 (18)62 (16)46 (18)45 (15)
LF (ms2/Hz)407 (521)248 (326)8.4 (12.5)7.7 (11.6)0.62 (0.69)1.04 (0.8)4.26 (3.4)2.36 (2.1)
HF (ms2/Hz)469 (420)198 (165)2.1 (1.6)2.1 (2.0)0.55 (0.3)0.34 (0.3)1.64 (1.2)0.86 (0.8)
LFnu46 (15)55 (23)
HFnu53 (16)44 (23)
LF/HF0.861.25
  • Values are mean (SD).

  • 4-150 p < 0.05, p < 0.01v the supine position.

  • DAP, diastolic arterial blood pressure (mm Hg); HF, high frequency; HFnu, high frequency fluctuations expressed in normalised units; LF, low frequency; LFnu, low frequency fluctuations expressed in normalised units; MFV, mean cerebral blood flow velocity (cm/s); RR, RR interval (ms); SAP, systolic arterial blood pressure (mm Hg).