Orthostatic hypertension and Dysautonomia
Orthostatic hypertension has also been associated with a number of conditions involving some form of autonomic dysfunction. In a recent study of patients with POTS in the context of disordered mast-cell activation, 38% (3/8) were shown to have orthostatic hypertension. Interestingly, in this group of patients, the orthostatic hypertension manifested as either a persistent hypertensive response to assumption of an upright posture or as a hypertensive crisis, with BP as high as 240/140, with upright posture. This has not been observed in patients who have POTS but do not have mast-cell activation disorder. Patients with baroreflex failure may also occasionally experience episodes of orthostatic hypertension.[26,27,28,29] These episodes are especially likely to occur in patients presenting with acute baroreflex failure. In the initial days and weeks after onset such patients have orthostatic hypertension immediately on standing, though it usually declines somewhat over the following few minutes. It is not a universal manifestation of baroreflex failure, which is more typically characterized by labile blood pressure and heart rate which track together. In a final phase of baroreflex failure, usually months to years after onset, orthostatic hypotension is more typically the dominant hemodynamic expression of the disorder. In the rare syndrome of norepinephrine transporter deficiency, an increase in blood pressure with upright posture can also be seen.
Nat Clin Pract Nephrol. 2006;2(8):424-431. © 2006
Nature Publishing Group
Cite this: Orthostatic Hypertension: When Pressor Reflexes Overcompensate - Medscape - Aug 01, 2006.