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Figure 3 Sequential hemodynamic changes during positive tilt testing in the second step. HR increased during upright posture, although not significantly, until just before positive response (until –1 min). HR throughout tilt testing was significantly higher in the ISP-dependent group than in the ISP-independent group. Mean BP dropped suddenly to the same level in both groups. The pattern of sequential changes was similar in both groups. *p < 0.05 when compared between groups. p < 0.05 when compared with baseline values.