Fig. 4.
Changes in heart rate (HR) and systolic blood pressure (BP) in postural tachycardia syndrome (POTS) and control subjects without initial orthostatic hypotension (No IOH). Change in heart rate (ΔHR) with standing (A) and change in systolic BP (ΔBP) (B) in POTS without IOH (No IOH POTS, solid line) and controls without IOH (No IOH control, dashed line). Minimum BP (BPmin), peak HR (HRmax), recovery BP (BPrcvr), recovery HR (HRrcvr), and time to steady-state HR are prolonged in POTS. HRrcvr and steady-state HR are increased in POTS, but earlier HRs are similar, as are all systolic BPs.