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Burchell AE, Sobotka PA, Hart EC, Nightingale AK, Dunlap ME. Chemohypersensitivity and autonomic modulation of venous capacitance in the pathophysiology of acute decompensated heart failure. Curr Heart Fail Rep 2013; 10:139-46. [PMID: 23504401 DOI: 10.1007/s11897-013-0135-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Heart failure is increasing in prevalence around the world, with hospitalization and re-hospitalization as a result of acute decompensated heart failure (ADHF) presenting a huge social and economic burden. The mechanism for this decompensation is not clear. Whilst in some cases it is due to volume expansion, over half of patients with an acute admission for ADHF did not experience an increase in total body weight. This calls into question the current treatment strategy of targeting salt and water retention in ADHF. An alternative hypothesis proposed by Fallick et al. is that an endogenous fluid shift from the splanchnic bed is implicated in ADHF, rather than an exogenous fluid gain. The hypothesis states further that this shift is triggered by an increase in sympathetic tone causing vasoconstriction in the splanchnic bed, a mechanism that can translocate blood rapidly into the effective circulating volume, generating the raised venous pressure and congestion seen in ADHF. This hypothesis encourages a new clinical paradigm which focuses on the underlying mechanisms of congestion, and highlights the importance of fluid redistribution and neurohormonal activation in its pathophysiology. In this article, we consider the concept that ADHF is attributable to episodic sympathetic hyperactivity, resulting in fluid shifts from the splanchnic bed. Chemosensitivity is a pathologic autonomic mechanism associated with mortality in patients with systolic heart failure. Tonic and episodic activity of the peripheral chemoreceptors may underlie the syndrome of acute decompensation without total body salt and water expansion. We suggest in this manuscript that chemosensitivity in response to intermittent hypoxia, such as experienced in sleep disordered breathing, may explain the intermittent sympathetic hyperactivity underlying renal sodium retention and acute volume redistribution from venous storage sites. This hypothesis provides an alternative structure to guide novel diagnostic and treatment strategies for ADHF.
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Affiliation(s)
- Amy E Burchell
- Bristol CardioNomics Group, Bristol Heart Institute, Bristol Royal Infirmary, Bristol, BS2 8HW, UK
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202
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Marcus NJ, Del Rio R, Schultz EP, Xia XH, Schultz HD. Carotid body denervation improves autonomic and cardiac function and attenuates disordered breathing in congestive heart failure. J Physiol 2013; 592:391-408. [PMID: 24247985 DOI: 10.1113/jphysiol.2013.266221] [Citation(s) in RCA: 124] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
In congestive heart failure (CHF), carotid body (CB) chemoreceptor activity is enhanced and is associated with oscillatory (Cheyne-Stokes) breathing patterns, increased sympathetic nerve activity (SNA) and increased arrhythmia incidence. We hypothesized that denervation of the CB (CBD) chemoreceptors would reduce SNA, reduce apnoea and arrhythmia incidence and improve ventricular function in pacing-induced CHF rabbits. Resting breathing, renal SNA (RSNA) and arrhythmia incidence were measured in three groups of animals: (1) sham CHF/sham-CBD (sham-sham); (2) CHF/sham-CBD (CHF-sham); and (3) CHF/CBD (CHF-CBD). Chemoreflex sensitivity was measured as the RSNA and minute ventilatory (VE) responses to hypoxia and hypercapnia. Respiratory pattern was measured by plethysmography and quantified by an apnoea-hypopnoea index, respiratory rate variability index and the coefficient of variation of tidal volume. Sympatho-respiratory coupling (SRC) was assessed using power spectral analysis and the magnitude of the peak coherence function between tidal volume and RSNA frequency spectra. Arrhythmia incidence and low frequency/high frequency ratio of heart rate variability were assessed using ECG and blood pressure waveforms, respectively. RSNA and VE responses to hypoxia were augmented in CHF-sham and abolished in CHF-CBD animals. Resting RSNA was greater in CHF-sham compared to sham-sham animals (43 ± 5% max vs. 23 ± 2% max, P < 0.05), and this increase was not found in CHF-CBD animals (25 ± 1% max, P < 0.05 vs. CHF-sham). Low frequency/high frequency heart rate variability ratio was similarly increased in CHF and reduced by CBD (P < 0.05). Respiratory rate variability index, coefficient of variation of tidal volume and apnoea-hypopnoea index were increased in CHF-sham animals and reduced in CHF-CBD animals (P < 0.05). SRC (peak coherence) was increased in CHF-sham animals (sham-sham 0.49 ± 0.05; CHF-sham 0.79 ± 0.06), and was attenuated in CHF-CBD animals (0.59 ± 0.05) (P < 0.05 for all comparisons). Arrhythmia incidence was increased in CHF-sham and reduced in CHF-CBD animals (213 ± 58 events h(-1) CHF, 108 ± 48 events h(-1) CHF-CBD, P < 0.05). Furthermore, ventricular systolic (3.8 ± 0.7 vs. 6.3 ± 0.5 ml, P < 0.05) and diastolic (6.3 ± 1.0 vs. 9.1 ± 0.5 ml, P < 0.05) volumes were reduced, and ejection fraction preserved (41 ± 5% vs. 54 ± 2% reduction from pre-pace, P < 0.05) in CHF-CBD compared to CHF-sham rabbits. Similar patterns of changes were observed longitudinally within the CHF-CBD group before and after CBD. In conclusion, CBD is effective in reducing RSNA, SRC and arrhythmia incidence, while improving breathing stability and cardiac function in pacing-induced CHF rabbits.
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Affiliation(s)
- Noah J Marcus
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, NE 68198-5850, USA.
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203
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Niewinski P, Janczak D, Rucinski A, Tubek S, Engelman ZJ, Jazwiec P, Banasiak W, Sobotka PA, Hart ECJ, Paton JFR, Ponikowski P. Dissociation between blood pressure and heart rate response to hypoxia after bilateral carotid body removal in men with systolic heart failure. Exp Physiol 2013; 99:552-61. [PMID: 24243836 DOI: 10.1113/expphysiol.2013.075580] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
While the ventilatory response to hypoxia is known to be mediated by the carotid bodies, the origin of the haemodynamic alterations evoked by hypoxia is less certain. Bilateral carotid body removal (CBR) performed to treat congestive heart failure may serve as a model to improve our understanding of haemodynamic responses to hypoxia in humans. We studied six congestive heart failure patients before and 1 month after CBR [median (interquartile range): age, 58.5 (56-61) years old; and ejection fraction, 32 (25-34)%]. Peripheral chemosensitivity (hypoxic ventilatory response) was equated to the slope relating lowest oxygen saturation to highest minute ventilation following exposures to hypoxia. Likewise, systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate (HR) slopes were calculated as slopes relating the lowest oxygen saturations to the highest SBP, DBP and HR responses. We found that CBR reduces the hypoxic ventilatory response (91%, P < 0.05), SBP (71%, P < 0.05) and DBP slopes (59%, P = 0.07). In contrast, the HR slope remained unchanged. The dissociation between the blood pressure and HR responses after CBR shows involvement of a different chemoreceptive site(s) maintaining the response to acute hypoxia. We conclude that carotid bodies are responsible for ventilatory and blood pressure responses, while the HR response might be mediated by the aortic bodies. The significant reduction of the blood pressure response to hypoxia after CBR suggests a decrease in sympathetic tone, which is of particular clinical relevance in congestive heart failure.
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Affiliation(s)
- Piotr Niewinski
- * Department of Cardiology, Centre for Heart Disease, 4th Military Hospital, 4 Wojskowy Szpital Kliniczny, Ul. Weigla 5, Wroclaw 50-981, Poland.
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204
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Dempsey JA, Xie A, Patz DS, Wang D. Physiology in medicine: obstructive sleep apnea pathogenesis and treatment--considerations beyond airway anatomy. J Appl Physiol (1985) 2013; 116:3-12. [PMID: 24201709 DOI: 10.1152/japplphysiol.01054.2013] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We review evidence in support of significant contributions to the pathogenesis of obstructive sleep apnea (OSA) from pathophysiological factors beyond the well-accepted importance of airway anatomy. Emphasis is placed on contributions from neurochemical control of central respiratory motor output through its effects on output stability, upper airway dilator muscle activation, and arousability. In turn, we consider the evidence demonstrating effective treatment of OSA via approaches that address each of these pathophysiologic risk factors. Finally, a case is made for combining treatments aimed at both anatomical and ventilatory control system deficiencies and for individualizing treatment to address a patient's own specific risk factors.
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Affiliation(s)
- Jerome A Dempsey
- James B. Skatrud Laboratory of Pulmonary & Sleep Medicine, Middleton Veterans Administration Hospital and Department of Population Health Sciences, University of Wisconsin-Madison, Madison Wisconsin
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205
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CT angiography in the detection of carotid body enlargement in patients with hypertension and heart failure. Neuroradiology 2013; 55:1319-22. [PMID: 24005832 DOI: 10.1007/s00234-013-1273-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Accepted: 08/13/2013] [Indexed: 10/26/2022]
Abstract
INTRODUCTION The carotid body (CB) has previously been found to be enlarged and hyperactive in various disease states such as heart failure (HF), hypertension (HTN), and respiratory disease. Evaluation of CB size in these disease states using imaging has not been performed. The purpose of this case-control study was to compare CB sizes in patients with HF and HTN with those of controls using CT angiography. METHODS A retrospective review was performed on 323 consecutive patients who had neck computed tomography angiography (CTA) exams in 2011. Following extensive review, 17 HF and HTN patients and 14 controls were identified. Two radiologists blinded to the patient disease status made consensus bilateral carotid body (CB) measurements on the CTA exams using a previously described standardized protocol. CB axial cross-sectional areas were compared between HF and HTN cases and controls using a paired t test. RESULTS The right CB demonstrated a mean cross-sectional area of 2.79 mm(2) in HF and HTN patients vs. 1.40 mm(2) in controls (p = 0.02). The left CB demonstrated a mean cross-sectional area of 3.13 mm(2) in HF and HTN patients vs. 1.53 mm in controls (p = 0.03). CONCLUSION Our results provide imaging evidence that the carotid bodies are enlarged in patients with HF and HTN. Our case-control series suggests that this enlargement can be detected on neck CTA.
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206
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Del Rio R, Marcus NJ, Schultz HD. Carotid chemoreceptor ablation improves survival in heart failure: rescuing autonomic control of cardiorespiratory function. J Am Coll Cardiol 2013; 62:2422-2430. [PMID: 24013056 DOI: 10.1016/j.jacc.2013.07.079] [Citation(s) in RCA: 151] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Revised: 06/19/2013] [Accepted: 07/01/2013] [Indexed: 01/08/2023]
Abstract
OBJECTIVES This study sought to investigate whether selective ablation of the carotid body (CB) chemoreceptors improves cardiorespiratory control and survival during heart failure. BACKGROUND Chronic heart failure (CHF) is a recognized health problem worldwide, and novel treatments are needed to better improve life quality and decrease mortality. Enhanced carotid chemoreflex drive from the CB is thought to contribute significantly to autonomic dysfunction, abnormal breathing patterns, and increased mortality in heart failure. METHODS Chronic heart failure was induced by coronary ligation in rats. Selective CB denervation was performed to remove carotid chemoreflex drive in the CHF state (16 weeks post-myocardial infarction). Indexes of autonomic and respiratory function were assessed in CB intact and CB denervated animals. CB denervation at 2 weeks post-myocardial infarction was performed to evaluate whether early targeted CB ablation decreases the progression of left ventricular dysfunction, cardiac remodeling, and arrhythmic episodes and improves survival. RESULTS The CHF rats developed increased CB chemoreflex drive and chronic central pre-sympathetic neuronal activation, increased indexes of elevated sympathetic outflow, increased breathing variability and apnea incidence, and desensitization of the baroreflex. Selective CB ablation reduced the central pre-sympathetic neuronal activation by 40%, normalized indexes of sympathetic outflow and baroreflex sensitivity, and reduced the incidence of apneas in CHF animals from 16.8 ± 1.8 events/h to 8.0 ± 1.4 events/h. Remarkably, when CB ablation was performed early, cardiac remodeling, deterioration of left ventricle ejection fraction, and cardiac arrhythmias were reduced. Most importantly, the rats that underwent early CB ablation exhibited an 85% survival rate compared with 45% survival in CHF rats without the intervention. CONCLUSIONS Carotid chemoreceptors play a seminal role in the pathogenesis of heart failure, and their targeted ablation might be of therapeutic value to reduce cardiorespiratory dysfunction and improve survival during CHF.
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Affiliation(s)
- Rodrigo Del Rio
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Noah J Marcus
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska
| | - Harold D Schultz
- Department of Cellular and Integrative Physiology, University of Nebraska Medical Center, Omaha, Nebraska.
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207
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Muller MD, Reed AB, Leuenberger UA, Sinoway LI. Physiology in medicine: peripheral arterial disease. J Appl Physiol (1985) 2013; 115:1219-26. [PMID: 23970534 DOI: 10.1152/japplphysiol.00885.2013] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Peripheral arterial disease (PAD) is an atherosclerotic condition that can provoke symptoms of leg pain ("intermittent claudication") during exercise. Because PAD is often observed with comorbid conditions such hypertension, dyslipidemia, diabetes, cigarette smoking, and/or physical inactivity, the pathophysiology of PAD is certainly complex and involves multiple organ systems. Patients with PAD are at high risk for myocardial infarction, stroke, and all-cause mortality. For this reason, a better physiological understanding of the pathogenesis and treatment options for PAD patients is necessary and forms the basis of this Physiology in Medicine review.
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Affiliation(s)
- Matthew D Muller
- Pennsylvania State University College of Medicine, Penn State Hershey Heart and Vascular Institute, Hershey, Pennsylvania
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208
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Shanks J, Manou-Stathopoulou S, Lu CJ, Li D, Paterson DJ, Herring N. Cardiac sympathetic dysfunction in the prehypertensive spontaneously hypertensive rat. Am J Physiol Heart Circ Physiol 2013; 305:H980-6. [PMID: 23913706 DOI: 10.1152/ajpheart.00255.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Recent studies in prehypertensive spontaneously hypertensive rats (SHR) have shown larger calcium transients and reduced norepinephrine transporter (NET) activity in cultured stellate neurons compared with Wistar-Kyoto (WKY) controls, although the functional significance of these results is unknown. We hypothesized that peripheral sympathetic responsiveness in the SHR at 4 wk of age would be exaggerated compared with the WKY. In vivo arterial pressure (under 2% isoflurane) was similar in SHRs (88 ± 2/50 ± 3 mmHg, n = 18) compared with WKYs (88 ± 3/49 ± 4 mmHg, n = 20). However, a small but significant (P < 0.05) tachycardia was observed in the young SHR despite the heart rate response to vagus stimulation (3 and 5 Hz) in vivo being similar (SHR: n = 12, WKY: n = 10). In isolated atrial preparations there was a significantly greater tachycardia during right stellate stimulation (5 and 7 Hz) in SHRs (n = 19) compared with WKYs (n = 16) but not in response to exogenous NE (0.025-5 μM, SHR: n = 10, WKY: n = 10). There was also a significantly greater release of [(3)H]NE to field stimulation (5 Hz) of atria in the SHR (SHR: n = 17, WKY: n = 16). Additionally, plasma levels of neuropeptide Y sampled from the right atria in vivo were also higher in the SHR (ELISA, n = 12 for both groups). The difference in [(3)H]NE release between SHR and WKY could be normalized by the NET inhibitor desipramine (1 μM, SHR: n = 10, WKY: n = 8) but not the α2-receptor antagonist yohimbine (1 μM, SHR: n = 7, WKY: n = 8). Increased cardiac sympathetic neurotransmission driven by larger neuronal calcium transients and reduced NE reuptake translates into enhanced cardiac sympathetic responsiveness at the end organ in prehypertensive SHRs.
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Affiliation(s)
- Julia Shanks
- Burdon Sanderson Cardiac Science Centre, Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, United Kingdom
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209
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Paton JFR, Ratcliffe L, Hering D, Wolf J, Sobotka PA, Narkiewicz K. Revelations about carotid body function through its pathological role in resistant hypertension. Curr Hypertens Rep 2013; 15:273-80. [PMID: 23828147 PMCID: PMC3712134 DOI: 10.1007/s11906-013-0366-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Much recent attention has been given to the carotid body because of its potential role in cardiovascular disease states. One disease, neurogenic hypertension, characterised by excessive sympathetic activity, appears dependent on carotid body activity that may or may not be accompanied by sleep-disordered breathing. Herein, we review recent literature suggesting that the carotid body acquires tonicity in hypertension. We predict that carotid glomectomy will be a powerful way to temper excessive sympathetic discharge in diseases such as hypertension. We propose a model to explain that signalling from the 'hypertensive' carotid body is tonic, and hypothesise that there will be a sub-population of glomus cells that channel separately into reflex pathways controlling sympathetic motor outflows.
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Affiliation(s)
- Julian F R Paton
- School of Physiology & Pharmacology, Bristol Heart Institute, University of Bristol, Medical Sciences Building, Bristol, England, UK.
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210
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Affiliation(s)
- Michael J Joyner
- Department of Anesthesiology, Mayo Clinic, Rochester, Minnesota, USA.
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211
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Paton JFR, Sobotka PA, Fudim M, Engelman ZJ, Hart ECJ, McBryde FD, Abdala AP, Marina N, Gourine AV, Lobo M, Patel N, Burchell A, Ratcliffe L, Nightingale A. Response to role of the carotid body in obesity-related sympathoactivation. Hypertension 2013; 61:e58. [PMID: 23819149 DOI: 10.1161/hypertensionaha.113.01301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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212
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Hart EC, McBryde FD, Burchell AE, Ratcliffe LEK, Stewart LQ, Baumbach A, Nightingale A, Paton JFR. Translational examination of changes in baroreflex function after renal denervation in hypertensive rats and humans. Hypertension 2013; 62:533-41. [PMID: 23817496 DOI: 10.1161/hypertensionaha.113.01261] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Renal denervation has shown promise in the treatment of resistant hypertension, although the mechanisms underlying the blood pressure (BP) reduction remain unclear. In a translational study of spontaneously hypertensive rats (n=7, surgical denervation) and resistant hypertensive human patients (n=8; 5 men, 33-71 years), we examined the relationship among changes in BP, sympathetic nerve activity, and cardiac and sympathetic baroreflex function after renal denervation. In humans, mean systolic BP (SBP; sphygmomanometry) and muscle sympathetic nerve activity (microneurography) were unchanged at 1 and 6 months after renal denervation (P<0.05). Interestingly, 4 of 8 patients showed a 10% decrease in SBP at 6 months, but sympathetic activity did not necessarily change in parallel with SBP. In contrast, all rats showed significant and immediate decreases in telemetric SBP and lumbar sympathetic activity (P<0.05), 7 days after denervation. Despite no change in SBP, human cardiac and sympathetic baroreflex function (sequence and threshold techniques) showed improvements at 1 and 6 months after denervation, particularly through increased sympathetic baroreflex sensitivity to falling BP. This was mirrored in spontaneously hypertensive rats; cardiac and sympathetic baroreflex sensitivity (spontaneous sequence and the Oxford technique) improved 7 days after denervation. The more consistent results in rats may be because of a more complete (>90% reduction in renal norepinephrine content) denervation. We conclude that (1) renal denervation improves BP in some patients, but sympathetic activity does not always change in parallel, and (2) baroreflex sensitivity is consistently improved in animals and humans, even when SBP has not decreased. Determining procedural success will be crucial in advancing this treatment modality.
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Affiliation(s)
- Emma C Hart
- School of Physiology and Pharmacology, Bristol Heart Institute, Medical Science Bldg, University of Bristol, Bristol, United Kingdom
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213
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Autonomic regulation of organ vascular resistances during hypoxemia in the cat. Auton Neurosci 2013; 177:181-93. [PMID: 23701915 DOI: 10.1016/j.autneu.2013.04.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 03/08/2013] [Accepted: 04/23/2013] [Indexed: 11/21/2022]
Abstract
This study aimed to dissect the roles played by the autonomic interoreceptors, the carotid bodies (cbs) and the aortic bodies (abs) on the vascular resistances of several organs in anesthetized, paralyzed, artificially ventilated cats challenged by systemic hypoxemia. Two 15 min challenges stimulated each of 5 animals in two different groups: (1) in the intact group hypoxic hypoxia (10% O2 in N2; HH) stimulated both abs and cbs, increasing neural output to the nucleus tractus solitarius (NTS); (2) in this group carbon monoxide hypoxia (30% O2 in N2 with the addition of CO; COH) stimulated only the abs, increasing neural output to the NTS. (3) In the second group in which their bilateral aortic depressor nerves had been transected only the cbs increased neural output to the NTS during the HH challenge; (4) in this aortic body resected group during COH neither abs nor cbs increased neural traffic to the NTS. CO and 10% O2 reduced Hb saturation to the same level. With the use of radiolabeled microspheres blood flow was measured in a variety of organs. Organ vascular resistance was calculated by dividing the aortic pressure by that organ's blood flow. The spleen and pancreas revealed a vasoconstriction in the face of systemic hypoxemia, thought to be sympathetic nervous system (SNS)-mediated. The adrenals and the eyes vasodilated only when cbs were stimulated. Vasodilation in the heart and diaphragm showed no effect of chemoreceptor stimulated increase in SNS output. Different chemoreceptor involvement had different effects on the organs.
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214
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Porzionato A, Macchi V, De Caro R. Role of the carotid body in obesity-related sympathoactivation. Hypertension 2013; 61:e57. [PMID: 23648701 DOI: 10.1161/hypertensionaha.113.01248] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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215
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Sobotka PA, Osborn JW, Paton JF. Restoring autonomic balance: future therapeutic targets. EUROINTERVENTION 2013; 9 Suppl R:R140-8. [DOI: 10.4244/eijv9sra24] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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216
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Niewiński P, Janczak D, Rucinski A, Jazwiec P, Sobotka PA, Engelman ZJ, Fudim M, Tubek S, Jankowska EA, Banasiak W, Hart ECJ, Paton JFR, Ponikowski P. Carotid body removal for treatment of chronic systolic heart failure. Int J Cardiol 2013; 168:2506-9. [PMID: 23541331 DOI: 10.1016/j.ijcard.2013.03.011] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2013] [Revised: 03/04/2013] [Accepted: 03/10/2013] [Indexed: 01/20/2023]
Abstract
BACKGROUND Augmented reflex response from peripheral chemoreceptors characterises chronic heart failure (CHF), contributes to autonomic imbalance and exercise intolerance and predicts poor outcome. METHODS AND RESULTS We present a case of a 56-year-old male patient with ischaemic CHF, who underwent surgical, unilateral carotid body resection to reduce peripheral chemosensitivity. At 2-month and 6-month follow-ups, we document a persistent decrease in peripheral chemosensitivity accompanied by an improvement in exercise capacity, sleep disordered breathing and quality of life. Autonomic balance was favourably affected as evidenced by improved heart rate variability and augmented cardiac baroreflex sensitivity. There were no procedure-related adverse events. CONCLUSIONS Denervation of a carotid body may offer a clinical strategy to restore autonomic balance and improve morbidity in heart failure (NCT01653821).
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Affiliation(s)
- Piotr Niewiński
- Department of Cardiology, Centre for Heart Disease, 4th Military Hospital, Wroclaw, Poland.
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217
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Affiliation(s)
- Gerald F DiBona
- Department of Internal Medicine and Molecular Physiology and Biophysics, University of Iowa, Carver College of Medicine, Iowa City, IA, USA.
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218
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McBryde FD, Abdala AP, Hendy EB, Pijacka W, Marvar P, Moraes DJA, Sobotka PA, Paton JFR. The carotid body as a putative therapeutic target for the treatment of neurogenic hypertension. Nat Commun 2013; 4:2395. [PMID: 24002774 DOI: 10.1038/ncomms3395] [Citation(s) in RCA: 179] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Accepted: 08/02/2013] [Indexed: 01/19/2023] Open
Abstract
In the spontaneously hypertensive (SH) rat, hyperoxic inactivation of the carotid body (CB) produces a rapid and pronounced fall in both arterial pressure and renal sympathetic nerve activity (RSA). Here we show that CB de-afferentation through carotid sinus nerve denervation (CSD) reduces the overactive sympathetic activity in SH rats, providing an effective antihypertensive treatment. We demonstrate that CSD lowers RSA chronically and that this is accompanied by a depressor response in SH but not normotensive rats. The drop in blood pressure is not dependent on renal nerve integrity but mechanistically accompanied by a resetting of the RSA-baroreflex function curve, sensitization of the cardiac baroreflex, changes in renal excretory function and reduced T-lymphocyte infiltration. We further show that combined with renal denervation, CSD remains effective, producing a summative response indicative of an independent mechanism. Our findings indicate that CB de-afferentation is an effective means for robust and sustained sympathoinhibition, which could translate to patients with neurogenic hypertension.
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Affiliation(s)
- Fiona D McBryde
- School of Physiology and Pharmacology, Bristol Heart Institute, Medical Sciences Building, University of Bristol, Bristol BS8 1TD, England
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