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Four faces of baroreflex failure: hypertensive crisis, volatile hypertension, orthostatic tachycardia, and malignant vagotoniaBACKGROUND: The baroreflex normally serves to buffer blood pressure against excessive rise or fall. Baroreflex failure occurs when afferent baroreceptive nerves or their central connections become impaired. In baroreflex failure, there is loss of buffering ability, and wide excursions of pressure and heart rate occur. Such excursions may derive from endogenous factors such as stress or drowsiness, which result in quite high and quite low pressures, respectively. They may also derive from exogenous factors such as drugs or environmental influences. METHODS AND RESULTS: Impairment of the baroreflex may produce an unusually broad spectrum of clinical presentations; with acute baroreflex failure, a hypertensive crisis is the most common presentation. Over succeeding days to weeks, or in the absence of an acute event, volatile hypertension with periods of hypotension occurs and may continue for many years, usually with some attenuation of pressor surges and greater prominence of depressor valleys during long-term follow-up. With incomplete loss of baroreflex afferents, a mild syndrome of orthostatic tachycardia or orthostatic intolerance may appear. Finally, if the baroreflex failure occurs without concomitant destruction of the parasympathetic efferent vagal fibers, a resting state may lead to malignant vagotonia with severe bradycardia and hypotension and episodes of sinus arrest. CONCLUSIONS: Although baroreflex failure is not the most common cause of the above conditions, correct differentiation from other cardiovascular disorders is important, because therapy of baroreflex failure requires specific strategies, which may lead to successful control.
Document ID
20040088288
Document Type
Reprint (Version printed in journal)
Authors
Ketch, Terry (Vanderbilt University Nashville, TN 37232-2195, United States)
Biaggioni, Italo
Robertson, RoseMarie
Robertson, David
Date Acquired
August 21, 2013
Publication Date
May 28, 2002
Publication Information
Publication: Circulation
Volume: 105
Issue: 21
ISSN: 0009-7322
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: PO1 HL56693
CONTRACT_GRANT: RR00095
CONTRACT_GRANT: 1U01NS33460
Distribution Limits
Public
Copyright
Other
Keywords
Review
Non-NASA Center
NASA Discipline Cardiopulmonary
Review, Tutorial