Fig. 2. Orthostatic-induced hemodynamic changes in a healthy control subject (A ) and a patient with complex regional pain syndrome (B ). Hemodynamic parameters were measured during10-min supine rest (Baseline), two times 10 min in 60^oupright position (Upright1, Upright2), and 10 min supine recovery (Recovery). The broken line  marks the initiation of the tilt. In the patient with complex regional pain syndrome (B ), the decrease in stroke volume in the upright position was not followed by a compensatory increase in heart rate (reduction in RR intervals) but by a reduction in cardiac output. To avoid decreases in the arterial blood pressure, there was a compensatory exaggerated increase in the total peripheral resistance (TPR) in the upright position. dBP = diastolic blood pressure; ms = milliseconds; RR interval = mean time between consecutive normal R waves in the QRS complexes; sBP = systolic blood pressure.