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1.
J Comp Neurol ; 532(7): e25654, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38980116

RESUMO

The flower-spray nerve endings are afferent nerve terminals in the carotid sinus that arise from carotid sinus nerve of glossopharyngeal nerve. However, the three-dimensional ultrastructural characteristics of flower-spray nerve endings and spatial relationships between the terminal parts and other cellular elements have not been fully understood. To elucidate their detailed relationship, backscattered electron imaging of serial sections was performed with a scanning electron microscope to produce a three-dimensional reconstruction of the flower-spray endings. The terminal parts of flower-spray endings were distributed horizontally approximately 5 µm outside the external elastic membrane in the tunica adventitia of the internal carotid artery. The three-dimensional reconstruction showed that the terminal parts of flower-spray endings were flat with irregular contours and were partially covered by the thin cytoplasmic processes of Schwann cells. The complex consisting of the nerve terminals and associated Schwann cells was surrounded by a multilayered basement membrane. The terminal parts of the endings were also surrounded by fibroblasts with elastic fibers and collagen fibrils. Secretory vesicles without an electron-dense core were observed in the terminal parts of the endings. The accumulation of vesicles just below the axonal membrane was observed in terminal parts not covered by Schwann cell cytoplasmic processes on both the luminal and basal sides. Swollen mitochondria, concentric membranous structures, and glycogen granule-like electron-dense materials were often noted in some of the terminal parts of the endings and the parent axon. Collectively, the present results suggest that flower-spray endings are baroreceptors because their morphology was similar to other mechanoreceptors. Furthermore, flower-spray endings may be affected by glutamate secreted in an autocrine manner.


Assuntos
Seio Carotídeo , Imageamento Tridimensional , Terminações Nervosas , Animais , Ratos , Masculino , Seio Carotídeo/inervação , Seio Carotídeo/ultraestrutura , Terminações Nervosas/ultraestrutura , Ratos Wistar , Microscopia Eletrônica de Varredura , Nervo Glossofaríngeo/ultraestrutura , Células de Schwann/ultraestrutura
2.
Cureus ; 16(2): e55237, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38558582

RESUMO

The hemodynamic milieu differs throughout the vascular tree because of varying vascular geometry and blood velocities. Accordingly, the risk of turbulence, which is dictated by the Reynolds and Dean numbers, also varies. Relatively high blood viscosity is needed to prevent turbulence in the left ventricle and aorta, where high-velocity blood changes direction several times. Low blood viscosity is needed in the capillaries, where erythrocytes pass through vessels with a diameter smaller than their own. In addition, higher blood viscosity is necessary when the cardiac output and peak blood velocity increase as a part of a sympathetic response or anemia, which occurs following significant hemorrhage. Blood viscosity, as reflected in systemic vascular resistance and vascular wall shear stress, is sensed, respectively, by cardiomyocyte stretching in the left ventricle and mechanoreceptors for wall shear stress in the carotid sinus. By controlling blood volume and red blood cell mass, the renin-aldosterone-angiotensin system and the systemic vascular resistance response control the hematocrit, the strongest intrinsic determinant of blood viscosity. These responses provide gross control of blood viscosity. Fine-tuning of blood viscosity in transient conditions is provided by hormonal control of erythrocyte deformability. The short half-life of some of these hormones limits their activity to specific vascular beds. Hormones that modulate blood viscosity include erythropoietin, angiotensin II, brain natriuretic factor, epinephrine, prostacyclin E2, antidiuretic hormone, and nitric oxide.

3.
Cureus ; 16(3): e56253, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38623094

RESUMO

When starting a mechanical thrombectomy, manual aspiration with balloon guide catheters inserted into the internal carotid artery (ICA) is an efficient method for thrombus aspiration. However, no complications associated with this procedure have been reported. This study describes the case of a 76-year-old man who presented to our hospital with total aphasia and complete right-sided paralysis due to chronic atrial fibrillation and left occlusion of the ICA. When the balloon guide catheter was inserted and inflated at the origin of the left ICA, the patient's systolic blood pressure suddenly decreased from 114 mm Hg to 44 mm Hg. This sudden hypotension may have been caused by the carotid sinus reflex. Hypotension improved following balloon deflation. The procedure was continued, resulting in complete recanalization of the left ICA. The patient died from acute exacerbation of interstitial pneumonia. Although this complication is rare, similar phenomena have been recognized in carotid artery stenting and the use of flow-diverting devices. To the best of our knowledge, this is the first report of a case wherein the carotid sinus reflex was induced by manual aspiration using a balloon guide catheter placed in the ICA. Clinicians should recognize the importance of ensuring that the proximal end of the balloon crosses the carotid sinus when dilating and occluding the ICA with a balloon to avoid the carotid sinus reflex.

4.
Front Neurosci ; 18: 1378473, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38646610

RESUMO

Bioelectronic medicine are an emerging class of treatments aiming to modulate body nervous activity to correct pathological conditions and restore health. Recently, it was shown that the high frequency electrical neuromodulation of the carotid sinus nerve (CSN), a small branch of the glossopharyngeal nerve that connects the carotid body (CB) to the brain, restores metabolic function in type 2 diabetes (T2D) animal models highlighting its potential as a new therapeutic modality to treat metabolic diseases in humans. In this manuscript, we review the current knowledge supporting the use of neuromodulation of the CSN to treat T2D and discuss the future perspectives for its clinical application. Firstly, we review in a concise manner the role of CB chemoreceptors and of CSN in the pathogenesis of metabolic diseases. Secondly, we describe the findings supporting the potential therapeutic use of the neuromodulation of CSN to treat T2D, as well as the feasibility and reversibility of this approach. A third section is devoted to point up the advances in the neural decoding of CSN activity, in particular in metabolic disease states, that will allow the development of closed-loop approaches to deliver personalized and adjustable treatments with minimal side effects. And finally, we discuss the findings supporting the assessment of CB activity in metabolic disease patients to screen the individuals that will benefit therapeutically from this bioelectronic approach in the future.

5.
Cureus ; 16(2): e54013, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38476805

RESUMO

Regional progression of head and neck malignancies can lead to carotid sinus tumors, causing hemodynamic instability and carotid sinus syndrome (CSS). A 60-year-old male with tonsillar squamous cell carcinoma developed profound positional bradycardia and hypotension immediately after extubation following dental extraction. The patient developed recurrent episodes of positional bradycardia and hypotension, leading to eventual pacemaker placement. Further workup revealed a large mass in the left neck and necrotic cervical lymphadenopathy, indicating CSS from malignancy compression. This case highlights the need for consideration of CSS in patients with known head and neck malignancy, particularly when postural hypotension and bradycardia are present.

6.
Ochsner J ; 24(1): 87-89, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38510226

RESUMO

Background: Carotid webs are nonatherosclerotic fibrous bands that may alter hemodynamic flow and increase the risk of platelet aggregation, leading to thromboembolism in young, otherwise healthy individuals. Although rare, carotid webs are important causes of thromboembolic strokes and are often overlooked in the routine workup for a stroke. Treating physicians and radiologists must recognize and properly manage patients who present with carotid webs to prevent recurrent thromboembolism. Case Report: A healthy 30-year-old female presented with slurred speech and unilateral left upper and lower extremity numbness. Imaging modalities showed an acute infarction of the right middle cerebral artery and bilateral carotid webs. The patient was managed operatively with a right carotid endarterectomy and discharged on day 3 of admission on a regimen of ticagrelor, amlodipine, and aspirin. The patient was asymptomatic at 1-year follow-up. Conclusion: Our case highlights the clinical relevance of considering carotid web as a potential etiology for ischemic stroke in young, otherwise healthy patients and emphasizes the importance of timely diagnosis and appropriate management to prevent recurrent cerebrovascular events.

7.
Age Ageing ; 53(2)2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38331395

RESUMO

Syncope can have devastating consequences, resulting in injuries, accidents or even death. In our ageing society, the subsequent healthcare usage, such as emergency room presentations, surgeries and hospital admissions, forms a significant and growing socioeconomic burden. Causes of syncope in the older adult include orthostatic hypotension, carotid sinus syndrome, vasovagal syncope, structural cardiac abnormalities, cardiac arrhythmias and conduction abnormalities. As stated in the recently published World Falls Guidelines, syncope in older adults often presents as falls, which is either due to amnesia for loss of consciousness, or pre-syncope leading to a fall, especially in those prone to falls with several other risk-factors for falls present. This difference in presentation can hinder the recognition of syncope. In patients with unexplained falls, or in whom the history comprises red flags for potential syncope, special attention to (pre)syncope is therefore warranted. When syncope is mistaken for other causes of a transient loss of consciousness, such as epileptic seizures, or when syncope presents as falls, patients are often referred to multiple specialists, which may in turn lead to excessive and unnecessary diagnostic testing and costs. Specialist services that are able to provide a comprehensive assessment can improve diagnostic yield and minimise diagnostic testing, thus improving patient satisfaction. Comprehensive assessment also leads to reduced length of hospital stay. Increasingly, geriatricians are involved in the assessment of syncope in the older patient, especially given the overlap with falls. Therefore, awareness of causes of syncope, as well as state-of-the-art assessment and treatment, is of great importance.


Assuntos
Hipotensão Ortostática , Síncope , Humanos , Idoso , Síncope/diagnóstico , Síncope/epidemiologia , Síncope/etiologia , Hipotensão Ortostática/diagnóstico , Envelhecimento , Fatores de Risco
8.
Trials ; 25(1): 33, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38195481

RESUMO

BACKGROUND: Patients undergoing carotid endarterectomy (CEA) have a high restenosis rate, which increases the risk of stroke, and there is still a lack of effective treatment for restenosis. The cause of stenosis is related to local inflammatory reactions. Some basic studies have shown that the inflammatory response causing arterial stenosis is closely related to the nerve axons distributed in its outer membrane, and that removal of the nerve is effective in reducing the inflammatory response to prevent arterial stenosis. Therefore, we propose to design a randomized controlled trial to study whether disconnecting the carotid sinus nerve during a CEA operation can reduce carotid arterial restenosis. METHOD/DESIGN: This study is a randomized, double-blind, single-center study. We will recruit 276 patients, who will be randomly divided into the experimental group and the control group. Based on the standard CEA operation, the operator will search for the carotid sinus nerve on the surface of the internal carotid artery and will entirely transect it in the experimental group. Both groups will be guided with the same postoperative treatment and will be followed up every 3 months for 3 years after the operation. The main indices observed will be the carotid restenosis rate, incidence and nature of carotid plaque, and carotid blood flow velocity. Other indices will be arrhythmia, blood pressure variability, and biomarkers of atherosclerosis, such as blood lipids, hypersensitive C-reactive protein (hs-CRP), homocysteine, and total bilirubin. DISCUSSION: It is expected that carotid sinus nerve transection will significantly reduce the occurrence of restenosis after CEA, decrease the incidence of ischemic stroke, and realize the effective primary prevention of stroke. TRIAL REGISTRATION: ChiCTR2300073652. Registered on July 18, 2023.


Assuntos
Seio Carotídeo , Acidente Vascular Cerebral , Humanos , Constrição Patológica , Artéria Carótida Interna , Denervação , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
Artigo em Inglês | MEDLINE | ID: mdl-37738307

RESUMO

BACKGROUND: Falls are a common cause of injury, hospitalization, functional decline, and residential care admission among older adults. Cardiovascular disorders are recognized risk factors for falls. This systematic review assesses the association between cardiovascular disorders and falls in older adults. METHODS: Systematic searches were conducted on MEDLINE and Embase, encompassing all literature published prior to December 31, 2022. Included studies addressed persons aged 50 years and older, and assessed the association between cardiovascular disorders and falls or the efficacy of cardiovascular-based interventions to reduce falls. Two reviewers independently extracted data and assessed study quality utilizing a modified Newcastle-Ottawa scale for observational studies, and the Cochrane Risk of Bias 2 tool for interventional studies. A systematic narrative analysis of all cardiovascular outcomes, and meta-analyses of unadjusted odds ratios (ORs) were performed. RESULTS: One hundred and eighty-four studies were included: 181 observational and 3 interventional. Several cardiovascular disorders, including stroke, coronary artery disease, valvular heart disease, arterial stiffness, arrhythmia, orthostatic hypotension, and carotid sinus hypersensitivity, were consistently associated with falls. In meta-analysis of unadjusted ORs, the largest positive pooled associations with falls during a 12-month reporting interval were for stroke (OR: 1.90, 95% confidence interval [CI]: 1.70-2.11), peripheral arterial disease (OR: 1.82, 95% CI: 1.12-2.95), atrial fibrillation (OR: 1.52, 95% CI: 1.27-1.82), and orthostatic hypotension (OR: 1.39, 95% CI: 1.18-1.64). CONCLUSIONS: Several cardiovascular disorders are associated with falls. These results suggest the need to incorporate cardiovascular assessments for patients with falls. This review informed the cardiovascular recommendations in the new World Guidelines for falls in older adults.Clinical Trials Registration Number: CRD42021272245.


Assuntos
Doenças Cardiovasculares , Hipotensão Ortostática , Acidente Vascular Cerebral , Humanos , Pessoa de Meia-Idade , Idoso , Hipotensão Ortostática/epidemiologia , Acidentes por Quedas , Doenças Cardiovasculares/epidemiologia , Fatores de Risco
10.
Cureus ; 15(11): e49256, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38143604

RESUMO

Supraventricular tachycardia (SVT) is the most common tachyarrhythmia of pregnancy. Catecholamine surges, the use of vasoactive agents during delivery, and increased cardiac output during pregnancy are the most common contributing factors to developing SVT. SVT is usually benign in presentation but can lead to more serious arrhythmias in patients with a history of mitral stenosis secondary to rheumatic heart disease. When an SVT is detected, organic heart causes should be ruled out first. Symptoms of SVT include shortness of breath, palpitations, syncope, sweating, chest pain, and dizziness. In patients who are refractory to pharmacologic management and hemodynamically unstable, electrical cardioversion has proven to be efficacious and safe in all trimesters. The initial treatment for hemodynamically stable patients is to attempt vagal maneuvers, such as carotid sinus massage or Valsalva maneuver. If the SVT does not convert to normal sinus rhythm, treatment with adenosine or beta-blockers may be initiated. Treatment with atenolol and verapamil should be avoided due to their teratogenic effects.

11.
Adv Anat Embryol Cell Biol ; 237: 13-35, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37946075

RESUMO

The carotid body (CB) is the main peripheral arterial chemoreceptor that registers the levels of pO2, pCO2 and pH in the blood and responds to their changes by regulating breathing. It is strategically located in the bifurcation of each common carotid artery. The organ consists of "glomera" composed of two cell types, glomus and sustentacular cells, interspersed by blood vessels and nerve bundles and separated by connective tissue. The neuron-like glomus or type I cells are considered as the chemosensory cells of the CB. They contain numerous cytoplasmic organelles and dense-cored vesicles that store and release neurotransmitters. They also form both conventional chemical and electrical synapses between each other and are contacted by peripheral nerve endings of petrosal ganglion neurons. The glomus cells are dually innervated by both sensory nerve fibers through the carotid sinus nerve and autonomic fibers of sympathetic origin via the ganglioglomerular nerve. The parasympathetic efferent innervation is relayed by vasomotor fibers of ganglion cells located around or inside the CB. The glial-like sustentacular or type II cells are regarded to be supporting cells although they sustain physiologic neurogenesis in the adult CB and are thus supposed to be progenitor cells as well. The CB is a highly vascularized organ and its intraorgan hemodynamics possibly plays a role in the process of chemoreception.


Assuntos
Corpo Carotídeo , Animais , Corpo Carotídeo/metabolismo , Células Quimiorreceptoras/fisiologia , Neurônios , Artéria Carótida Primitiva , Gânglios , Mamíferos
12.
Life Sci ; 335: 122281, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37984513

RESUMO

AIMS: The carotid bodies are sensors that detect physiological signals and convey them to the central nervous system, where the stimuli are processed inducing reflexes through efferent pathways. Recent studies have demonstrated that electrical stimulation of the carotid sinus nerve (CSN) triggers the anti-inflammatory reflex under different conditions. However, whether this electrical stimulation attenuates colitis was never examined. This study aimed to evaluate if the electrical CSN stimulation attenuates the experimental colitis induced by intrarectal administration of acetic acid in rats. METHODS: Electrodes were implanted around the CSN to stimulate the CSN, and a catheter was inserted into the left femoral artery to record the arterial pressure. The observation of hypotensive responses confirmed the effectiveness of the electrical CNS stimulation. This maneuver was followed by a 4 % acetic acid or saline administered intrarectally. After 24 h, colons were segmented into distal and proximal parts for macroscopy, histological and biochemical assessment. KEY FINDINGS: As expected, the electrical CSN stimulation was effective in decreasing arterial pressure in saline and colitis rats. Moreover, electrical CSN stimulation effectively reduced colonic tissue lesions, colitis scores, and histopathologic parameters associated with colitis. In addition, the CSN stimulation also reduced the colonic mucosa pro-inflammatory cytokine interleukin-1 beta, and increased the anti-inflammatory interleukin-10, in rats submitted to colitis. SIGNIFICANCE: These findings indicated that electrical CSN stimulation breaks the vicious cycle of local colon inflammation in colitis, which might contribute to its better outcome.


Assuntos
Seio Carotídeo , Colite , Ratos , Animais , Seio Carotídeo/fisiologia , Ácido Acético , Colite/induzido quimicamente , Colite/terapia , Reflexo , Estimulação Elétrica , Anti-Inflamatórios
13.
J Arrhythm ; 39(5): 810-812, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37799800

RESUMO

Carotid sinus syndrome (CSS) is a rare condition leading to recurrent syncope. Permanent pacemaker implantation is the mainstay treatment of cardioinhibitory CSS. In this report, we present a CSS patient with reproducible atrioventricular block during carotid massage, who was treated with cardioneuroablation.

14.
Anat Cell Biol ; 56(4): 463-468, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37696755

RESUMO

The carotid sinus nerve (CSN) is well known as mediating baroreflexes. However, studies of its detailed histological analysis are scant in the literature. Therefore, the current anatomical study sought to better elucidate the microanatomy of the CSN. Ten fresh frozen adult cadavers underwent dissection of the CSN. Then, it was harvested and submitted for histological and immunohistochemical staining. Specimens were all shown to be nerve fibers on histology and immunohistochemistry. We identified tyrosine hydroxylase positive fibers in all CSN specimens. These fibers were always found to be within the CSN and not on its surface i.e., epineurium. Based on our findings, the majority of fibers contained in the CSN are tyrosine positive in nature. Further studies are necessary to understand the true function of this autonomic nerve fibers.

15.
J Stroke Cerebrovasc Dis ; 32(9): 107296, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37567132

RESUMO

OBJECTIVES: The risk factors for post-carotid artery stenting severe hemodynamic instability remain elusive. This study aimed to identify the predictors of severe hemodynamic instability during and persisted after carotid artery stenting. MATERIALS AND METHODS: Consecutive patients who underwent carotid artery stenting for extracranial carotid artery stenosis at a single-center between September 2018 and July 2021 were retrospectively assessed. The predictive factors of severe hemodynamic instability intraoperation and post-operation were analyzed. RESULTS: Among the 139 patients included, 63 experienced severe hemodynamic instability, with 45 and 18 cases occurring intra and postoperatively, respectively. Persistent was observed in 21 patients. Smoke exposure (odds ratio [OR], 2.38; p=0.039), carotid bifurcation stenosis (OR, 0.91; p=0.018), and large-diameter balloon (>4 mm) dilatation (OR, 11.95; p<0.001) were identified as independent risk factors for hemodynamic instability at any stage of carotid artery stenting. Intraoperatively, large-diameter balloon (>4 mm) dilatation was associated with an increased risk of hemodynamic instability occurrence (OR, 4.67; p=0.01), whereas general anesthesia (OR, 0.19; p=0.001) and a longer distance from the stenosis to the carotid bifurcation (OR, 0.89; p=0.01) were negatively associated with hemodynamic instability. Furthermore, smoking exposure (OR, 3.73; p=0.03), large diameter balloon dilatation (OR, 6.12; p=0.032), distance from stenosis to bifurcation (OR, 0.85; p=0.047) and long-stent (40 mm) implantation (OR, 0.84 [95% confidence interval, 0.74-0.95]; p=0.007) could independently predict persistent hemodynamic instability. CONCLUSION: Patients with a smoking history, lesions near the carotid bulb, or dilatation using a large-diameter balloon were most likely to suffer severe hemodynamic instability. General anesthesia can protect against severe hemodynamic instability only intraoperatively. Long-term stent implantation may reduce persistent hemodynamic instability.


Assuntos
Angioplastia com Balão , Estenose das Carótidas , Humanos , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/terapia , Estenose das Carótidas/complicações , Hemodinâmica , Constrição Patológica/complicações , Estudos Retrospectivos , Angioplastia com Balão/efeitos adversos , Stents , Artérias Carótidas/cirurgia , Resultado do Tratamento
16.
Blood Press ; 32(1): 2232873, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37470450

RESUMO

Uncontrolled hypertension drives the global burden of increased cardiovascular disease (CVD) morbidity and mortality. Although high blood pressure (BP) is treatable and preventable, only half of the patients with hypertension undergoing treatment have their BP controlled. The failure of polypharmacy to attain adequate BP control may be due to a lack of physiological response, however, medication non-adherence and clinician inertia to increase treatment intensity are critical factors associated with poor hypertension management. The long-time medication titration, lifelong drug therapy, and often multi-drug treatment strategy are frustrating when the BP goal is not achieved, leading to increased CVD risk and a substantial burden on the healthcare system. Growing evidence indicates that neurohumoral activation is critical in initiating and maintaining elevated BP and its adverse consequences. Over the past decades, device-based therapies targeting the mechanisms underlying hypertension pathophysiology have been extensively studied. Among these, robust clinical experience for hypertension management exists for renal denervation (RDN) and baroreflex activation therapy (BAT), carotid body denervation (CBD), central arteriovenous anastomosis, and to a lesser extent, deep brain stimulation. Future studies are warranted to define the role of device-based approaches as an alternative or adjunctive treatment option to treat hypertension.


Systemic hypertension is a growing contributor to global disease burden and premature cause of death worldwide.The percentage of patients achieving target BP levels remains largely inadequate.Hypertension is characterised by activation of the sympathetic nervous system, with the magnitude depending on age and the disease severity.Device-based interventions have been extensively studied to directly target the relevant sympathetic neural pathophysiological mechanisms involved in BP control.Modulation of the chronic sympathetic outflow with CBD or BAT shows promise for the treatment of poorly controlled hypertension in addition to antihypertensive medicines.The BP response to device-based therapies appears variable and cannot be predicted before the procedure.Until more robust evidence related to patient selection, procedural and technical aspects is available, chemoreflex and baroreflex neuromodulation therapy should be restricted to randomised sham-controlled trials performed in experienced centres.


Assuntos
Doenças Cardiovasculares , Hipertensão , Humanos , Anti-Hipertensivos/uso terapêutico , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/fisiologia , Doenças Cardiovasculares/etiologia , Seio Carotídeo , Rim , Resultado do Tratamento
17.
Adv Exp Med Biol ; 1427: 203-208, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37322351

RESUMO

Metformin is a glucose-lowering, insulin-sensitizing drug that is commonly used in the treatment of type 2 diabetes (T2D). In the last decade, the carotid body (CB) has been described as a metabolic sensor implicated in the regulation of glucose homeostasis, being CB dysfunction crucial for the development of metabolic diseases, such as T2D. Knowing that metformin could activate AMP-activated protein kinase (AMPK) and that AMPK has been described to have an important role in CB hypoxic chemotransduction, herein we have investigated the effect of chronic metformin administration on carotid sinus nerve (CSN) chemosensory activity in basal and hypoxic and hypercapnic conditions in control animals. Experiments were performed in male Wistar rats subjected to 3 weeks of metformin (200 mg/kg) administration in the drinking water. The effect of chronic metformin administration was tested in spontaneous and hypoxic (0% and 5% O2) and hypercapnic (10% CO2) evoked CSN chemosensory activity. Metformin administration for 3 weeks did not modify the basal CSN chemosensory activity in control animals. Moreover, the CSN chemosensory response to intense and moderate hypoxia and hypercapnia was not altered by the chronic metformin administration. In conclusion, chronic metformin administration did not modify chemosensory activity in control animals.


Assuntos
Corpo Carotídeo , Diabetes Mellitus Tipo 2 , Metformina , Ratos , Masculino , Animais , Seio Carotídeo/inervação , Seio Carotídeo/metabolismo , Ratos Wistar , Metformina/farmacologia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Corpo Carotídeo/fisiologia , Hipóxia , Hipercapnia
18.
Heart Rhythm ; 20(9): 1279-1286, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37329936

RESUMO

BACKGROUND: Cardioneuroablation (CNA) is a novel treatment for reflex syncope. The effect of aging on CNA efficacy is not fully understood. OBJECTIVE: The purpose of this study was to assess the impact of aging on candidacy and efficacy of CNA for treating vasovagal syncope (VVS), carotid sinus syndrome (CSS), and functional bradyarrhythmia. METHODS: The ELEGANCE (cardionEuroabLation: patiEnt selection, imaGe integrAtioN and outComEs) multicenter study assessed CNA in patients with reflex syncope or severe functional bradyarrhythmia. Patients underwent pre-CNA Holter electrocardiography (ECG), head-up tilt testing (HUT), and electrophysiological study. CNA candidacy and efficacy was assessed in 14 young (18-40 years), 26 middle-aged (41-60 years), and 20 older (>60 years) patients. RESULTS: Sixty patients (37 men; mean age 51 ± 16 years) underwent CNA. The majority (80%) had VVS, 8% had CSS, and 12% had functional bradycardia/atrioventricular block. Pre-CNA Holter ECG, HUT, and electrophysiological findings did not differ across age groups. Acute CNA success was 93%, without differences between age groups (P = .42). Post-CNA HUT response was negative in 53%, vasodepressor in 38%, cardioinhibitory in 7%, and mixed in 2%, without differences across age groups (P = .59). At follow-up (8 months, interquartile range 4-15), 53 patients (88%) were free of symptoms. Kaplan-Meier curves did not show differences in event-free survival between age groups (P = .29). The negative predictive value of a negative HUT was 91.7%. CONCLUSION: CNA is a viable treatment for reflex syncope and functional bradyarrhythmia in all ages, and is highly effective in mixed VVS. HUT is a key step in postablation clinical assessment.


Assuntos
Síncope Vasovagal , Masculino , Pessoa de Meia-Idade , Humanos , Adulto , Idoso , Síncope Vasovagal/diagnóstico , Síncope Vasovagal/cirurgia , Bradicardia/diagnóstico , Bradicardia/cirurgia , Seleção de Pacientes , Síncope/diagnóstico , Teste da Mesa Inclinada/métodos , Envelhecimento , Reflexo
19.
J Cardiovasc Electrophysiol ; 34(5): 1305-1309, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36950851

RESUMO

Head and neck tumors can rarely cause carotid sinus syndrome and this often resolves by surgical intervention or palliative chemoradiotherapy. If these modalities are not an option or are ineffective, the most preferred treatment is permanent pacemaker therapy. Here, we present the first case of cardioneuroablation treatment performed in patient with oropharyngeal squamous cell cancer who developed recurrent asystole and syncope attacks due to compression of the carotid sinus on neck movement.


Assuntos
Neoplasias de Cabeça e Pescoço , Neoplasias de Células Escamosas , Marca-Passo Artificial , Humanos , Seio Carotídeo , Síncope/diagnóstico , Síncope/etiologia , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/terapia , Marca-Passo Artificial/efeitos adversos , Neoplasias de Células Escamosas/complicações , Neoplasias de Células Escamosas/terapia
20.
BMC Cardiovasc Disord ; 23(1): 134, 2023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36918774

RESUMO

BACKGROUND: A high prevalence of nasopharyngeal carcinoma (NPC) has been found in China, but it rarely occurs with syncope. Studies have demonstrated that syncope due to NPC may be related to carotid sinus syndrome, glossopharyngeal irritation, and parapharyngeal and retropharyngeal space lesions. Such patients require evaluation by nasopharyngoscopy and head magnetic resonance imaging/computed tomography. There is no known single effective treatment for these patients. Various interventions may be considered in an effort to relieve syncope, including vasoconstrictive drugs, cardiac pacemaker implantation, radiotherapy and chemotherapy, and surgical resection. CASE PRESENTATION: This case report describes a 56-year-old man who developed recurrent syncope with atrial fibrillation, a long RR interval, and hypotension. A single chamber pacemaker was fitted, but it failed to relieve the symptom. Cranial magnetic resonance imaging and pathological tests led to a final diagnosis of NPC. After six courses of chemotherapy and 35 sessions of radiotherapy, the patient became asymptomatic. However, he died from a massive uncontrolled hemorrhage in the nasopharynx two years later. CONCLUSIONS: This case brings attention to the fact that syncope can be a symptom of NPC. Due to the insidiously malignant nature of this cancer, when a patient presents with syncope, clinicians should bear in mind this connection, albeit a rare one. There are at least two ways of treating NPC-associated syncope, but there is disagreement about which is the most effective.


Assuntos
Hipotensão , Neoplasias Nasofaríngeas , Masculino , Humanos , Pessoa de Meia-Idade , Carcinoma Nasofaríngeo/complicações , Carcinoma Nasofaríngeo/terapia , Síncope , Hipotensão/etiologia , Imageamento por Ressonância Magnética/efeitos adversos , Neoplasias Nasofaríngeas/complicações , Neoplasias Nasofaríngeas/terapia
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