SELECTIVE DEFECT OF BAROREFLEX BLOOD-PRESSURE BUFFERING WITH INTACT CARDIOINHIBITION IN A WOMAN WITH FAMILIAL ANIRIDIA

We report a symptomatic failure of the baroreceptor blood pressure (BP ) buffering mechanism in a woman with familial aniridia. Her baseline BP oscillated at 0.1 Hz, the frequency of Mayer waves, with increased amplitude on standing without orthostatic hypotension. Although sudomo tor function was normal, cutaneous thermoregulatory function and BP re sponse to Valsalva's maneuver were abnormal. The defective BP buffer m echanism suggests Mayer waves could be a sympathetic mediated cardiova scular resonance. Baroreceptor cardioinhibition was intact. We presume that the lesion is in the rostral aspect of the dorsal medulla oblong ata.