Abnormalities of autonomic nervous system in hyperadrenergic orthostatic hypotension: description of a case.

Hyperadrenergic orthostatic hypotension was diagnosed in a 27-year-old man because of recurrent episodes of hypotension associated with high plasma noradrenaline levels. In this patient, laboratory tests were performed to evaluate autonomic nervous system function. Decreased response to Valsalva maneuver and carotid sinus massage indicated decreased baroreflex and vagal responsiveness, respectively. Cardiovascular response to the handgrip was reduced in comparison to controls. Passive leg raise showed normal reduction of plasma norepinephrine, indicating normal responsiveness of cardiopulmonary receptors. 'Non-dipper' profile in the ambulatory blood pressure monitoring provided further evidence for an impaired autonomic control of cardiovascular function in this patient. This report suggests the presence of autonomic dysfunction in hyperadrenergic orthostatic hypotension.