Paroxysmal hypertension due to sinoaortic baroreceptor denervation in humans.

Aksamit, Timothy R.; Floras, John S.; Victor, Ronald G.; Aylward, Philip E.

doi:10.1161/01.hyp.9.3.309

Cited by 76 publications

(35 citation statements)

References 19 publications

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“…9,10 Therefore, the presence of cardiac rhythmicity of MSNA after BCBR may originate from residual carotid baroreceptors and/or unaffected aortic and cardiopulmonary baroreceptors. Absence of pulse synchronicity of MSNA in a patient after selective sinoaortic denervation as the result of bilateral carotid bypass surgery and mediastinal irradiation 6 suggests that MSNA rhythmicity is not generated by cardiopulmonary mechanoreceptors. BCBR does not result in a permanent elevation of resting MSNA (this study), nor does it result in chronic hypertension.…”

Section: Effect Of Bcbr On Baseline Msnamentioning

confidence: 98%

“…The findings of excessive rises in plasma catecholamines during these attacks and of exaggerated pressor responses to cold and mental stress in these patients suggest the loss of baroreflexmediated inhibition of efferent sympathetic nerve activity. 4,6 In a previous study, we have demonstrated that although BCBR elicits the full-blown syndrome of baroreflex failure only in a minority of patients, 9 baroreflex control of heart rate is impaired and blood pressure variability is increased in the long term after BCBR. 9,10 Whether BCBR also affects baroreflex control of sympathetic outflow has not yet been established in humans.…”

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confidence: 95%

“…Baroreflex control of both heart rate and sympathetic nerve activity were attenuated in patients as compared with control subjects [heart rate baroreflex sensitivity: 3.68Ϯ0. 4,6,7 and carotid endarterectomy. 8 The resulting clinical syndrome of baroreflex failure is characterized by recurrent bouts of unrestrained sympathetic excitation, manifesting as severe hypertension, headache, and diaphoresis.…”

mentioning

confidence: 99%

“…3 In addition, normal cardiac rhythmicity of MSNA is lost after baroreceptor denervation. Apart from experimental denervation, iatrogenic denervation of baroreceptors may occur as complication of bilateral carotid body tumor resection (BCBR), 4,5 neck or mediastianal irradiation, 4,6,7 and carotid endarterectomy. 8 The resulting clinical syndrome of baroreflex failure is characterized by recurrent bouts of unrestrained sympathetic excitation, manifesting as severe hypertension, headache, and diaphoresis.…”

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Baroreflex Control of Muscle Sympathetic Nerve Activity After Carotid Body Tumor Resection

et al. 2003

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Abstract-Bilateral carotid body tumor resection causes a permanent attenuation of vagal baroreflex sensitivity. We retrospectively examined the effects of bilateral carotid body tumor resection on the baroreflex control of sympathetic nerve traffic. Muscle sympathetic nerve activity was recorded in 5 patients after bilateral carotid body tumor resection (1 man and 4 women, 51Ϯ11 years) and 6 healthy control subjects (2 men and 4 women, 50Ϯ7 years). Baroreflex sensitivity was calculated from changes in R-R interval and muscle sympathetic nerve activity in response to bolus injections of phenylephrine and nitroprusside. In addition, sympathetic responses to the Valsalva maneuver and cold pressor test were measured. The integrated neurogram of patients and control subjects contained a similar pattern of pulse synchronous burst of nerve activity. Baroreflex control of both heart rate and sympathetic nerve activity were attenuated in patients as compared with control subjects [heart rate baroreflex sensitivity: 3.68Ϯ0. 4,6,7 and carotid endarterectomy. 8 The resulting clinical syndrome of baroreflex failure is characterized by recurrent bouts of unrestrained sympathetic excitation, manifesting as severe hypertension, headache, and diaphoresis. The findings of excessive rises in plasma catecholamines during these attacks and of exaggerated pressor responses to cold and mental stress in these patients suggest the loss of baroreflexmediated inhibition of efferent sympathetic nerve activity. 4,6 In a previous study, we have demonstrated that although BCBR elicits the full-blown syndrome of baroreflex failure only in a minority of patients, 9 baroreflex control of heart rate is impaired and blood pressure variability is increased in the long term after BCBR. 9,10 Whether BCBR also affects baroreflex control of sympathetic outflow has not yet been established in humans.The aim of this study was to examine the chronic effects of BCBR on the baroreflex control of sympathetic nerve activity. In this cross-sectional, retrospective study of patients with BCBR and age-matched healthy control subjects, sympathetic baroreflex sensitivity was calculated from MSNA responses to (de-)activation of baroreceptors by phenylephrine and nitroprusside bolus injections. In addition, MSNA responses to the Valsalva maneuver and cold pressor test were assessed. Medical Center Nijmegen, the Netherlands, were included in this study. Individual information on tumor size, additional tumor localizations, and surgical details of these 5 patients are shown in the Table. The median interval between the second operation and the study was 6.7 years (range, 4.4 to 20.3 years). Patients were free of diabetes and neurological, cardiovascular, and pulmonary disease. Six healthy subjects (2 men and 4 women) served as control subjects. Full medical history and physical examination including blood pressure measurements revealed no abnormalities. Groups were matched for age (BCBR: 51.2Ϯ10.8 versus control subjects: 50.0Ϯ6.5 years), body mass index (24.8Ϯ1.1 ve...

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Section: Effect Of Bcbr On Baseline Msnamentioning

confidence: 98%

mentioning

confidence: 95%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Baroreflex Control of Muscle Sympathetic Nerve Activity After Carotid Body Tumor Resection

et al. 2003

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“…Theoretically, one would like to assess baroreflex regulation of heart rate and sympathetic nerve traffic, which are both impaired in baroreflex failure. 4,7 However, recording of sympathetic activity is only available in a few specialized institutions. Abnormal baroreflex tests alone are not sufficient to diagnose baroreflex failure.…”

Section: Diagnostic Testingmentioning

confidence: 99%

Baroreflex Failure

et al. 2005

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Abstract-The baroreflex receives less attention nowadays because most students of hypertension are convinced that faulty volume regulation by the kidneys is responsible for long-term blood pressure increases. However, unusual patients with bilateral destruction of the normal blood pressure-sensing mechanisms can develop profound chronic hypertension. We present 2 patients with baroreflex failure. Both had volatile hypertension with systolic readings up to 300 mm Hg documented over years. Both had muscle sympathetic nerve activity that was increased even while resting. Treating these patients was a stochastic challenge. The therapy is frequently based on medicines that are no longer commonly prescribed. Key Words: baroreflex Ⅲ sympathetic nervous system Ⅲ autonomic nervous system Ⅲ hypotension Ⅲ bradycardia T he arterial baroreflex buffers acute fluctuations in blood pressure that occur during posture, stress, or other maneuvers. When blood pressure rises, vascular distension is transduced into nervous electrical activity, triggering reflex parasympathetic activation and sympathetic inhibition. Heart rate is slowed and vascular resistance is decreased, buffering the increase in blood pressure. Conversely, baroreceptor activity decreases when blood pressure falls, producing a reflex-mediated increase in heart rate and peripheral resistance. Baroreceptor activity is reset during sustained increases in blood pressure so that in patients with essential hypertension, baroreceptor responsiveness is maintained. However, the resetting of the baroreflex plays at least a permissive role in perpetuation of hypertension. Guyton argued that the baroreflex is responsible for the minute-to-minute regulation of blood pressure, but that the long-term blood pressure regulation is related to volume mechanisms adjusted by the kidneys. 1 However, faulty baroreflexes can occasionally influence long-term blood pressure regulation. An example is the condition of baroreflex failure. Such patients are a diagnostic challenge and a therapeutic nightmare. Case 1A 65-year-old woman was referred to our center for evaluation of possible baroreflex failure. Her chief symptom was volatile hypertension. The patient had a family history of arterial hypertension. Antihypertensive therapy was initiated at a young age and blood pressure readings were stable for many years. Twenty-two years before admission, a papillary thyroid cancer was diagnosed. She was successfully treated with thyroidectomy and local radiation followed by radioiodine treatment. Six years before admission, the patient experienced a neck trauma during a skiing accident. A left common carotid artery stenosis secondary to radiation injury was treated with angioplasty and stent implantation 4 years before admission. After the skiing accident, blood pressure became highly volatile. Systolic blood pressure values as high as 230 mm Hg had been recorded even during antihypertensive therapy with amlodipine, ramipril, spironolactone, metoprolol, and moxonidine. The hypertension was exacerba...

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Severe Paroxysmal Hypertension (Pseudopheochromocytoma)

Mann¹

1999

Arch Intern Med

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Severe, symptomatic paroxysmal hypertension always generates suspicion of a pheochromocytoma, a catecholamine-secreting tumor. However, most patients with this disorder do not have this tumor and their condition remains undiagnosed and ineffectively treated. This case series, summarizing the course of 21 such patients, suggests a cause and an effective treatment approach. All 21 patients insisted that the paroxysms were not related to stress or emotional distress, initially discouraging consideration of a link to emotions. Nevertheless, with careful psychosocial interviewing, the disorder could be attributed to emotions patients were not aware of, and, therefore, unable to report. Such emotions were related either to previous severe emotional trauma or to a general tendency to keep distressful emotions out of awareness. With treatment based on this understanding, further paroxysms were eliminated in 13 (62%) of 21 patients. Alpha- plus beta-blockade was used, combined, when necessary, with an antidepressant agent, with or without an anxiolytic agent. In 3 cases, the disorder was cured with psychotherapy alone. Because the presenting symptoms are physical rather than emotional, patients present to internists and primary care physicians rather than to psychotherapists. For this reason, more awareness of this disorder in the medical community is needed.

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Paroxysmal hypertension due to sinoaortic baroreceptor denervation in humans.

Cited by 76 publications

References 19 publications

Baroreflex Control of Muscle Sympathetic Nerve Activity After Carotid Body Tumor Resection

Baroreflex Control of Muscle Sympathetic Nerve Activity After Carotid Body Tumor Resection

Baroreflex Failure

Severe Paroxysmal Hypertension (Pseudopheochromocytoma)

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