[Case of baroreflex failure after bilateral revascularization of the cervical carotid artery]

We report a patient of baroreflex failure two years after bilateral cervical internal carotid artery (ICA) revascularization. A 76-year-old hypertensive man was admitted to our hospital after suffering multiple syncopal events for the past 2 years prior to admission. He received bilateral surgical and endovascular revascularization for stenotic lesions of the ICA orifices 4 years ago. Intervention consisted of carotid endarterectomy and carotid stenting for the right and left ICAs, respectively. Head T2-weighted magnetic resonance images demonstrated multiple high intensity signals in the basal ganglia bilaterally. To investigate his autonomic function, head-up tilt test, 24-hour ambulatory blood pressure measurements, and Valsalva's maneuver were performed. The patient demonstrated marked orthostatic hypotension without increment of heart rate, increased variability of blood pressure and abnormal hypertensive surges in a single 24 hour period, and abnormal response of heart rate during Valsalva's maneuver. These findings were indicative of impaired baroreflex-mediated vasomotor and heart rate control. Other examinations involving hematological analysis, cardiac function assessment, and scintigraphy for pheochromocytoma were within normal limits except for a marked increase in plasma norepinephrine during hypertensive surge. We therefore considered that he had baroreflex failure resulting from previous bilateral ICA orifice revascularization. The patient was given diazepam during hospitalization. After then, his blood pressure stabilized somewhat and syncopal attacks were controlled. Our case suggests that patients, who undergo bilateral ICA orifice revascularization and present with syncopal attacks, should be considered baroreflex failure even if the patient is post-operative several years. Long-term follow up should therefore be necessitated in patients who undergo bilateral carotid revascularization.