Fig. 2.

Percent cerebral blood flow reduction and percent cardiac index reduction, relative to the supine pre-tilt values, at end-tilt, and in the supine recovery phase post-tilt, in patients with a normal HR and BP response and in patients with POTS. Percent cerebral blood flow reduction and percent cardiac index reduction, relative to the supine pre-tilt values, at end-tilt, and in the supine recovery phase post-tilt, in patients with a normal heart rate and blood pressure response and in patients with POTS. CBF: cerebral blood flow; normHRBP: normal heart rate and blood pressure response; CI: cardiac index; POTS: postural orthostatic tachycardia syndrome; *: columns significantly different from zero (P < 0.0001); #: columns not significantly different from zero.