Figure 1. Twenty-four–hour ambulatory BP monitor recording of a patient recently hospitalized for syncope and treated with fludrocortisone for suspected neurogenic OH.

The reading is notable for blood pressure variability, nocturnal hypertension, and a morning drop in blood pressure after a short walk that correlated with severe lightheadedness (denoted by ***). Sleep period is depicted with a thick horizontal line between 8:45 pm and 7:45 am. Orthostatic vitals the day after ambulatory monitoring were consistent with orthostatic hypotension (OH) on the basis of the following systolic blood pressures/diastolic blood pressures/heart rates: 175 mm Hg/82 mm Hg/67 bpm (supine), 152 mm Hg/79 mm Hg/70 bpm (seated), 109 mm Hg/67 mm Hg/72 bpm (≈1 minute standing), and 115 mm Hg/67 mm Hg/73 bpm (≈3 minutes of standing). BP indicates blood pressure; and MAP, mean arterial pressure.