Table 2.

Time to nadir after head-up tilt

	Time to Nadir, s
	TPRi	MFV	CVRi
Control	2.00 ± 1.2	3.90 ± 3.8	3.20 ± 2.8
−10°	4.70 ± 2.1§†	2.00 ± 1.7	5.78 ± 2.6*‡
−25°	4.40 ± 1.3§‡	2.20 ± 1.5	6.10 ± 1.9§‡
−55°	3.90 ± 1.4§	2.50 ± 1.8	4.40 ± 1.4†

Data are means ± SD, in seconds.

TPRi, index of total peripheral resistance calculated as mean arterial pressure/cardiac output (dyn·s·cm⁻⁵); MFV, mean cerebral blood flow velocity (cm/s); CVRi, cerebrovascular resistance index (mmHg/cm/s).

^*P < 0.05,

^§P < 0.01, significant difference vs. control condition.

^†P < 0.05,

^‡P < 0.01, significant difference vs. MFV.