Sympathetic neural prosthesis for managing orthostatic hypotension.

A prototype electromechanical analogue of the sympathetic division of the baroreceptor reflex arc was used to maintain blood pressure automatically in two patients with neurogenic orthostatic hypotension. The device prevented significant and sustained reductions in mean blood pressure when the patients were tilted up to 85 degrees. Upon achieving the preset mean blood pressure, the device maintained this pressure with a standard error of less than 2 mm Hg. Similar results were obtained when the patients were walking. The device did not cause supine hypertension during the trials.