Binswanger and the carotid sinus (Historical Note) / Binswanger e o seio carotídeo (Nota Histórica)

The 'carotid sinus' is an arterial dilatation placed usually at the beginning of the internal carotid artery. The medial wall of this dilatation appears modified, with a reduction of the media, and an increase of the adventitia, besides containing nervous terminations, forming thus a sensorial structure. This dilatation was possibly first observed by John Bell (1808), and clearly described and named by Cruveilhier (1834). However, many authors credited the initial finding to Burns (1811), followed by a number of researchers, as Luschka (1862), Manson (1866), Meyer (1876), Schäfer (1878), most with a view related to aneurysm formation, but some seeing the formation as a normal trait. Finally, Binswanger (1879) reaffirmed that the dilatation meant a normal feature of the region, based on his own observations, and on the opinion of some forerunners. Besides, he was the first to classify this dilatation regarding the variability of its localization. The thinning of this region was initially identified by Meyer (1876) and detailed by Binswanger (1879), at bare eye visual inspection and on microscopic examination, observing there an important reduction of the width of the tunica media. Despite Meyer's effort, and mostly Binswanger's, the microscopic findings are incipient, what can be explained by the limitations of the histological techniques at the time. However, there is no doubt that Binswanger and his forerunners provided important information for the upcoming research, comprising the structure, innervation, and function of this formation.

O 'seio carotídeo' é uma dilatação arterial situada geralmente no início da artéria carótida interna. A parede medial dessa dilatação apresenta-se modificada, com redução da média e aumento da adventícia, além de conter terminações nervosas, constituindo assim uma estrutura sensorial. Essa dilatação foi possivelmente observada primeiro por John Bell (1808) e claramente descrita e denominada por Cruveilhier (1834). Entretanto, muitos autores creditam o achado inicial a Burns (1811), seguido por numerosos pesquisadores, como Luschka (1862), Manson (1866), Meyer (1876), Schäfer (1878), a maioria com olhar relacionada à formação de aneurisma, mas alguns vendo a formação como uma característica normal. Finalmente, Binswanger (1879) reafirmou que a dilatação representava um aspecto normal da região, baseado em observações próprias e na opinião de alguns de seus antecessores. Além disso, foi o primeiro a classificar essa dilatação quanto a variabilidade de sua localização. O adelgaçamento dessa região foi identificado inicialmente por Meyer (1876) e detalhado por Binswanger (1879), à inspeção visual a olho nu e ao exame microscópico, observando lá uma importante redução da espessura da túnica média. Apesar do esforço de Meyer e sobretudo de Binswanger, os achados microscópicos são incipientes, o que pode ser explicado pelas limitações das técnicas histológicas daquele tempo. Todavia, não há dúvida que Binswanger e seus precursores proveram importante informação para as pesquisas que se sucederam, compreendendo a estrutura, inervação e função dessa formação.

Luschka and the carotid body / Luschka e o corpo carotídeo

The 'carotid body' is a small structure sited at the bifurcation of the common carotid artery. The macroscopic features of the carotid body, and items of the extrinsic nervous, and vascular supplies, were initially described by Taube (1743), complemented by a number of authors that followed, proceeding until Luschka (1962), who added the first microscopic study. The macroscopic features of the carotid body, including location, extrinsic innervation, and vascular supply, then provided, were described in a relatively satisfactory manner. However, despite Luschka's great and admirable effort, the microscopic findings seem to be flawed, what can be ascribed to the technical limitations at the time, and the artifacts due to the used procedures. Nevertheless, there is no doubt that Luschka and his forerunners provided an important step for forthcoming research on the carotid body, and its innervation.

O 'corpo carotídeo' é uma pequena estrutura situada na bifurcação da artéria carótida comum. Os aspectos macroscópicos do corpo carotídeo e itens sobre o suprimento nervoso e vascular extrínsecos foram descritos inicialmente por Taube (1743), complementados por um certo número de autores que seguiram, prosseguindo até Luschka (1962), que acrescentou o primeiro estudo microscópico. Os aspectos macroscópicos do corpo carotídeo, incluindo localização, inervação extrínseca e suprimento vascular, então providos, foram descritos de modo relativamente satisfatório. Entretanto, apesar do grande e admirável esforço de Luschka, os achados microscópicos aparecem falhos, o que pode ser atribuído às limitações técnicas daquele tempo e a artefatos devidos aos procedimentos utilizados. Todavia, não há dúvida que Luschka e seus precursores proveram um importante passo para pesquisas que vieram sobre o corpo carotídeo e da sua inervação.

Síndrome del seno carotídeo asociado a linfoma B cervical / Carotid sinus syndrome associated to cervical B-cell lymphoma

Resumen Se describe el caso de un varón de 75 años con tumoración submaxilar derecha de 5 meses de evolución sin diagnóstico etiológico, que consultó por episodios de síncope precedidos por disnea y sudoración profusa de instalación súbita. Durante su internación se detectaron, en el monitoreo electrocardiográ fico, pausas mayores a 3 segundos luego de la lateralización cervical reproduciendo los síntomas mencionados y asociadas a sensación de pérdida inminente de la conciencia, por lo que se implantó marcapasos transitorio. Se realizó biopsia de la masa tumoral cervical, consistente con linfoma B difuso de células grandes no centro germinal, y se inició quimioterapia. Luego de dicho tratamiento quimioterápico se observó reducción significativa de la masa tumoral con abolición de los síntomas asociados a las maniobras cervicales. El diagnóstico definitivo fue síndrome del seno carotídeo maligno asociado a linfoma cervical.

Abstract We present the case of a 75-year-old male with history of 5 months of right submaxillary tumor, with no clear etiology, who consulted for episodes of syncope preceded by dyspnea and sudden onset of profuse sweating. During his stay at the hospital, electrocardiographic records showed more than 3-second-long pauses after head movements, with a sensation of imminent loss of consciousness associated. A temporary pacemaker was required. Biopsy showed a diffuse non-germinal large B-cell B lymphoma, which required chemotherapy. After the first chemotherapy session, a significant reduction of the tumoral mass was observed, with abolition of the symptoms associated to cervical movements. The definitive diagnosis was malignant carotid sinus syndrome associated with cervical lymphoma.

Forensic Progress on Death Following Carotid Sinus Inhibition / 法医学杂志

Death after carotid sinus trauma is usually attributed to death from inhibition, a type of sudden death. Currently, the number of incidents is scarce, and related studies are few. Therefore, how to determine the involvement of carotid sinus and determine the role of diseases in the cause of death has always been a difficult point in forensic investigation. This article sorts out the research literature on carotid sinus related death at home and abroad in recent years, systematically reviews the anatomic structure of the carotid sinus nerve, the clinical epidemiology of carotid sinus syndrome, and the research on the death mechanism of carotid sinus injury at home and abroad in recent years, in order to provide references for forensic pathology research and prosecution.

Long-Term Mortality in Cardioinhibitory Carotid Sinus Hypersensitivity Patient Cohort / Mortalidade de uma Coorte de Portadores da Resposta Cardioinibitória à Massagem do Seio Carotídeo - Estudo Longitudinal com 11 Anos de Seguimento

Abstract Background: Cardioinhibitory carotid sinus hypersensitivity (CICSH) is defined as ventricular asystole ≥ 3 seconds in response to 5-10 seconds of carotid sinus massage (CSM). There is a common concern that a prolonged asystole episode could lead to death directly from bradycardia or as a consequence of serious trauma, brain injury or pause-dependent ventricular arrhythmias. Objective: To describe total mortality, cardiovascular mortality and trauma-related mortality of a cohort of CICSH patients, and to compare those mortalities with those found in a non-CICSH patient cohort. Methods: In 2006, 502 patients ≥ 50 years of age were submitted to CSM. Fifty-two patients (10,4%) were identified with CICSH. Survival of this cohort was compared with that of another cohort of 408 non-CICSH patients using Kaplan-Meier curves. Cox regression was used to examine the relation between CICSH and mortality. The level of statistical significance was set at 0.05. Results: After a maximum follow-up of 11.6 years, 29 of the 52 CICSH patients (55.8%) were dead. Cardiovascular mortality, trauma-related mortality and the total mortality rate of this population were not statistically different from that found in 408 patients without CICSH. (Total mortality of CICSH patients 55.8% vs. 49,3% of non-CICSH patients; p: 0.38). Conclusion: At the end of follow-up, the 52 CICSH patient cohort had total mortality, cardiovascular mortality and trauma-related mortality similar to that found in 408 patients without CICSH.

Resumo Fundamento: A resposta cardioinibitória (RCI) à massagem do seio carotídeo (MSC) caracteriza-se por assistolia ≥ 3 segundos provocada por 5 a 10 segundos de MSC. Existe uma preocupação de que pacientes com RCI e episódios prolongados de assistolia possam falecer em consequência direta de bradiarritmia, ou em decorrência de lesão cerebral, trauma grave ou arritmia ventricular pausa dependente. Objetivos: Determinar a mortalidade total, a mortalidade cardiovascular e a mortalidade relacionada ao trauma de uma coorte de pacientes com RCI à MSC e comparar essas mortalidades com as de uma coorte de pacientes sem RCI à MSC. Métodos: Em 2006, 502 pacientes com idade igual ou superior a 50 anos foram submetidos à MSC. Destes, 52 pacientes (10,4%) foram identificados com RCI. A sobrevida desta coorte foi comparada àquela observada em uma coorte de 408 pacientes sem RCI por meio de curvas de Kaplan-Meier. A regressão de Cox foi utilizada para avaliação da relação entre a RCI à MSC e a mortalidade. Variáveis com p < 0,05 foram consideradas estatisticamente significativas. Resultados: Após seguimento máximo de 11,6 anos, 29 dos 52 portadores de RCI (55,8%) faleceram. A mortalidade total, a mortalidade cardiovascular e a mortalidade relacionada ao trauma desta coorte de pacientes não foram significativamente diferentes daquelas encontradas nos 408 pacientes sem RCI (mortalidade total com RCI: 55,8% versus 49,3% sem RCI; p: 0,38). Conclusões: No fim do seguimento, a mortalidade dos 52 portadores de RCI foi semelhante à observada em uma coorte de pacientes sem RCI. A mortalidade cardiovascular e a relacionada ao trauma também foi semelhante nas duas coortes.

Prevalence and One-year Outcome of Carotid Sinus Hypersensitivity in Unexplained Syncope: A Prospective Cohort Study from South India

Background Carotid sinus syndrome accounts for one third of patients who presents with unexplained syncope. Prevalence of carotid sinus hypersensitivity (CSH) in Indians has not been studied till now. Objectives To assess the prevalence and associations of CSH in symptomatic patients above 50 years and to study its prognostic significance pertaining to sudden cardiac death, syncope, recurrent pre syncope and falls on 1 year follow up. Methods Patients above 50 years who presented with unexplained syncope, recurrent syncope or falls were considered cases and those without these symptoms were considered as controls. All the patients underwent carotid sinus massage and their responses noted. All symptomatic patients were followed up and observed for events like sudden cardiac death, syncope, recurrent pre syncope and falls during 1 year follow up. Patients with recurrent syncope and predominant cardioinhibitory syncope were advised permanent pacemaker implantation. Results A total of 252 patients were screened, 130 patients constituted cases and 49 patients constituted controls. CSH was demonstrable in 32% (n = 42) of cases as compared to 8% (n = 4) in controls (p < 0.001). Cardioinhibitory response was the predominant response (88%, n = 38) followed by mixed response (12%, n = 4). CSH was associated with advancing age, male gender (93%, n = 39, p < 0.001) and history of smoking (63%, n = 27, p = 0.009). Composite outcomes of sudden cardiac death, syncope, recurrent pre syncope and falls were significantly higher in patients with symptomatic CSH than in those without it (45%, n = 16 vs. 6.8%, n = 6; p < 0.001). Conclusions In conclusion, the prevalence of CSH in patients above 50 yrs with unexplained syncope was high in our population. Patients with CSH and baseline symptoms developed recurrent syncope during follow up. Carotid sinus massage should be a part of routine examination protocol for unexplained syncope.

Pilot study for a novel delta carotid sinus massage in increasing parasympathetic tone: a randomized, prospective, cross-over, comparative study with conventional method

OBJECTIVE: This study examined the efficacy of new delta carotid sinus massage (CSM) versus conventional CSM (CM). METHODS: This prospective, cross-over study was conducted on 26 healthy volunteers with a normal sinus rhythm. CM and delta CSM (DM) were performed in all participants. In both cases, the CSM was performed, where the maximal carotid pulse was palpated. DM differed from CM in that the physician moves the palpating finger in the opposite direction of the carotid pulse at least twice. The mean and longest R-R intervals and mean and lowest heart rates (HRs) at the baseline and during the procedure for each technique were compared. The mean differences between the baseline and procedure R-R intervals and the HRs for each technique were also evaluated. RESULTS: The baseline mean and longest R-R intervals and baseline mean and lowest HRs were similar both groups (P>0.05). The procedure DM mean and longest R-R intervals (22.7±3.1, 26.4±4.9) were significantly greater than the CM corresponding values (22.0±3.1, 24.6±3.5; P<0.001, P=0.003). Procedure DM mean and lowest HRs (67.3±9.7, 58.6±10.7) were significantly lower than the CM corresponding values (69.4±10.0, 61.8±8.9; P=0.001, P=0.003). The differences in the R-R interval and HR between the procedure and baseline were significant (mean and longest R-R intervals with CM [1.3±1.5 and 2.1±1.9] vs. DM [2.0±1.4 and 3.8±3.1], P<0.001, P=0.004; mean and lowest HRs with CM [4.2±4.3 and 5.8±4.6] vs. DM [6.3±4.6 and 9.1±6.5], P<0.001, P=0.005). CONCLUSION: DM is more effective in generating a more potent vagal tone than CM.

Preoperative carotid sinus block prevents the low hemodynamic state in the perioperative period of carotid artery stenting / 中华普通外科杂志

Objective To evaluate carotid sinus block (CAS) in preventing the low hemodynamic state in the perioperative period of carotid artery stenting (CAS).Method A prospective single-center randomized controlled study was conducted on 172 patients with internal carotid artery stenosis receiving CAS from May 2015 to May 2018.Patients were randomly divided into group A treated with local anesthesia of the carotid artery sinus of the trouble side under the guidance of ultrasound preoperatively and group B without local block anesthesia.The carotid artery stenosis rate,the maximum intraoperative reduction of blood pressure and heart rate,the use of atropine and vasopressor were monitored and compared between the two groups.Results There were no significant differences between the two groups in preoperative general data,degree of stenosis,plaque nature,degree of residual stenosis (P ＞ 0.05).The maximum reduction of intraoperative blood pressure and heart rate in group A was significantly lower than that in group B,and the number and dose of intraoperative atropine were smaller than those in group B (P ＜ 0.05).The number of postoperative patients with low hemodynamic status in group A and the time period of vasopressor use were significantly less than those in group B (P ＜ 0.05).Conclusion Preoperative carotid sinus block anesthesia is safe and effective in preventing low hemodynamic status in perioperative period of CAS.

Carotid Sinus Massage in Syncope Evaluation: A Nonspecific and Dubious Diagnostic Method / Massagem do Seio Carotídeo na Avaliação da Síncope: Um Método Diagnóstico Inespecífico e Duvidoso

Abstract Background: Carotid sinus hypersensitivity (CSH) is a frequent finding in the evaluation of syncope. However, its significance in the clinical setting is still dubious. A new criterion was proposed by Solari et al. with a symptomatic systolic blood pressure (SBP) cut-off value of ≤ 85 mmHg to refine the vasodepressor (VD) response diagnosis. Objective: To determine and compare the response to carotid sinus massage (CSM) in patients with and without syncope according to standard and proposed criteria. Methods: CSM was performed in 99 patients with and 66 patients without syncope. CSH was defined as cardioinhibitory (CI) for asystole ≥ 3 seconds, or as VD for SBP decrease ≥ 50 mmHg. Results: No differences in the hemodynamic responses were observed during CSM between the groups, with 24.2% and 25.8% CI, and 8.1% and 13.6% VD in the symptomatic and asymptomatic groups, respectively (p = 0.466). A p value < 0.050 was considered statistically significant. During the maneuvers, 45 (45.45%) and 34 (51.5%) patients in the symptomatic and asymptomatic groups achieved SBP below ≤ 85 mmHg. Symptoms were reported especially in those patients in whom CSM caused a SBP decrease to below 90 mmHg and/or asystole > 2.5 seconds, regardless of the pattern of response or the presence of previous syncope. Conclusion: The response to CSM in patients with and without syncope was similar; therefore, CSH may be an unspecific condition. Clinical correlation and other methods of evaluation, such as long-lasting ECG monitoring, may be necessary to confirm CSH as the cause of syncope.

Resumo Fundamento: A hipersensibilidade do seio carotídeo (HSC) é um achado frequente na avaliação da síncope. Entretanto, o valor da resposta positiva é ainda incerto no contexto clínico. Novo critério diagnóstico para tentar refinar a resposta vasodepressora (VD) foi proposto por Solari et al. com determinação da queda sintomática da pressão arterial sistólica (PAS) a níveis ≤ 85 mmHg como ponto de corte. Objetivo: Determinar e comparar a resposta à massagem do seio carotídeo (MSC) em pacientes com e sem síncope de acordo com os critérios vigentes e propostos. Métodos: A MSC foi realizada em 99 pacientes com síncope e 66 pacientes sem síncope. A HSC foi definida como cardioinibitória (CI), se assistolia ≥ 3 segundos, ou VD, se queda da PAS ≥ 50 mmHg. Resultados: Não foram observadas diferenças na resposta hemodinâmica entre os grupos durante a MSC, com 24,2% e 25,8% de resposta CI, e 8,1% e 13,6% de resposta VD nos grupos sintomático e assintomático, respectivamente (p = 0,466). Considerou-se p < 0,05 estatisticamente significativo. Durante as manobras, 45 (45,45%) e 34 (51,5%) pacientes nos grupos sintomático e assintomático atingiram PAS ≤ 85 mmHg. Sintomas foram relatados principalmente por pacientes em que a MSC reduziu a PAS para menos de 90 mmHg e/ou causou assistolia > 2,5 segundos, independentemente do padrão da resposta ou história de síncope prévia. Conclusão: As respostas à MSC em pacientes com e sem síncope foram semelhantes. Portanto, a HSC pode ser uma condição inespecífica. A correlação clínica mais precisa e outros métodos para avaliação, como monitoramento por ECG de longa duração, podem ser necessários para confirmação da HSC como causa da síncope.

Hypersensitivity of carotid sinus. A forgotten cause of syncope and falls in the elderly / Hipersensibilidad del seno carotídeo. Una causa olvidada de síncope y caídas en el adulto mayor

Abstract: Carotid sinus syndrome is a cause of syncope and falls in the elderly that is frequently overlooked because of different reasons, nevertheless it might be present in up to 40% of subjects older than 80 years. Its physiopathology is not clear even if it has many common points with neutrally mediated syncope. Its main feature is that the trigger for the symptoms is the stimulation of the neck's baro-receptors. The diagnosis is usually clinical and the carotid sinus massage confirms it by reproducing the symptoms when it induces longer than three second asystole or blood pressure drops higher than 50 mmHg. Its treatment has many controversial points and the options are limited when it comes to the vasodepressor variety. In the cardio-inhibitory variety, the most accepted treatment is a pacemaker implant, nonetheless, the recurrence rates still high.

Resumen: El síndrome del seno carotídeo es una causa de síncope y caídas en el adulto mayor que suele pasarse por alto por diferentes razones; sin embargo, está presente hasta en un 40% de los mayores de 80 años de edad. La fisiopatología no está del todo clara pero tiene muchos puntos en común con el síncope neuralmente mediado, con la peculiaridad de que el disparador depende de la estimulación de los barorreceptores del cuello. El diagnóstico es clínico y las maniobras de masaje del seno carotídeo lo confirman al reproducir los síntomas cuando se inducen asistolias superiores a tres segundos y caídas de presión arterial mayores a 50 mmHg con el masaje. El tratamiento presenta muchos puntos de controversia y hay opciones limitadas cuando se trata de la variedad vasodepresora. En el caso de la cardioinhibición, la opción más adecuada es el implante de un marcapasos, pero aún así las tasas de recurrencia siguen siendo elevadas.

Risk factors for carotid sinus reactions during carotid artery stenting: a retrospective case series / 国际脑血管病杂志

Objective To investigate the risk factors for carotid sinus reactions (CSR) during internal carotid artery stenting (CAS).Methods The clinical data of 36 patients treated with CAS were enrolled retrospectively.The patients were divided into either a CSR group or a non-CSR group according to whether they had CSR or not.The risk factors for CSR during procedure were analyzed using univariate and multivariate logistic regression analysis.Results Of the 36 patients,25 had CRS (7 simple hypotension,4 simple bradycardia,and 14 both co-existence).The constituent ratios of the patients of the age ≥ 75 years (64.00％ vs.27.27％ ;x2 =2.384,P =0.028),degree of CAS 70％ to 99％ (76.00％ vs.36.36％ ; x2 =4.430,P =0.035),symptomatic stenosis (72.00％ vs.36.36％ ; x2 =4.082,P =0.043),calcified plaque (76.00％ vs.36.36％ ;x2 =4.430,P =0.035),distance from stenosis to bifurcation ≤ 10 mm (72.00％ vs.27.27％ ;x2 =5.029,P =0.025) and balloon expansion (64.00％ vs.18.18％ ;x2 =44.483,P =0.000) in the CSR group were significantly higher than those in the non-CSR group.Multivariate logistic regression analysis showed that age ≥ 75 years (odds ratio [OR] 1.520,95％ confidence interval [CI] 1.376-4.369; P =0.034),distance from stenosis to bifurcation ≤ 10 wm (OR 2.432,95％ CI 2.423-3.421; P =0.041) and balloon expansion (OR 3.631,95％ CI 1.764-4.738; P=0.003) were the independent risk factors for occurring CSR during CAS.Conclusions CSR is a common perforrance during CAS.Advanced age,distance from stenosis to bifurcation ≤ 10 mm and balloon expansion are the independent risk factors for occurring CSR.

Effect of isolated carotid sinus perfusion with propofol on plasma endothelin and nitric oxide levels in diabefic rats / 中华麻醉学杂志

Objective To investigate the effect of isolated carotid sinus perfusion with propofol on plasma endothelin and nitric oxide levels in diabetic rats.Methods Healthy adult Wistar rats weighing 180-220 g were used in this study.Diabetes mellitus was induced by intraperitoneal streptozotocin 30 mg/kg and confirmed by blood glucose ≥ 16.7 mmol/L.Thirty-six rats in which diabetes mellitus model was successfully established were randomly divided into 3 groups ( n =12):control group (group DC) ;low dose propofol group (group DP1 ) and high dose propofol group (group DP2 ).Another 36 non-diabetic rats were also randomly divided into 3 group ( n =12 each):control group (group NC) ; low dose propofol group group (group NP1 ) and high dose propofol (group NP2 ).After 30 min isolated carotic sinus perfusion with K-H solution (control groups),50 μmol/L propofol in K-H solution (low dose propofol groups) or 100 μmol/L propofol in K-H solution (high dose propofol groups),blood samples were taken for determination of plasma endothelin and nitric oxide concentrations.Results The plasma endothelin concentration was lower and nitric oxide concentration higher in groups DP1 and DP2 than in group DC,and in group DP1 than in group DP2 ( P ＜ 0.05).The plasma endothelin concentration was higher and nitric oxide concentration lower in group NPi than in group DP1,and in group NP2 than in group DP2 ( P ＜ 0.05 ).Conclusion Propofol can decrease endothelin level and increase nitric oxide level in diabetic or non-diabetic rats through local effect on carotid sinus,and the effect is stronger in diabetic rats than in non-diabetic rats.

Highly increased blood pressure following stellate ganglion block: A case report

Stellate ganglion block (SGB) is a procedure that is widely used for many diseases associated with sympathetically-maintained pain in the head, neck, and upper extremities. Various hemodynamic changes may occur after SGB. Among them, we experienced two patients who developed highly increased blood pressure after SGB. We suspect that the spread of local anesthetics produced parasympathetic blockade of the vagus nerve, an imbalance between the sympathetic and parasympathetic activities and deafferentiation of the glossopharyngeal and vagus nerve, which both innervated the carotid sinus, as the mechanism of this increased blood pressure.

Prolonged Hemodynamic Depression After Bilateral Carotid Angioplasty and Stent Insertion

Hemodynamic depression (hypotension and bradycardia) can occur during or after carotid angioplasty and stenting (CAS) due to stretching of the baroreceptors in the carotid sinus. The predisposing factors of hemodynamic depression have not been reported previously. In general, hemodynamic depression after CAS may continue for up to 3-5 days, but disappears within 7 days. We report herein a 65-year-old man with severe hemodynamic depression after sequential CAS, and discuss the possible causes from an anatomical point of view.

Temporary cardiac arrest in patient under robotically assisted total thyroidectomy causing carotid sinus hypersensitivity: A case report / 대한마취과학회지

Carotid sinus hypersensitivity (CSH) is an exaggerated response to carotid sinus baroreceptor stimulation. Bradycardia, hypotension, and syncope are common manifestations of CSH. A 31-year-old female patient was scheduled for a robotically assisted endoscopic total thyroidectomy. No problems occurred during anesthetic induction. Sudden cardiac arrest occurred near dissection of the diseased thyroid. However, while atropine was administered, the patient soon recovered to normal sinus rhythm. Subsequent bradycardia or hypotension was not followed until the end of surgery.

Incidência de complicações relacionadas à massagem do seio carotídeo em 502 pacientes ambulatoriais / Incidencia de complicaciones relacionadas al masaje del seno carotídeo en 502 pacientes ambulatorios / Complications related to carotid sinus massage in 502 ambulatory patients

FUNDAMENTO: A massagem do seio carotídeo (MSC) é uma técnica simples, de baixo custo e com muitas indicações. OBJETIVO: Determinar a segurança da MSC em pacientes ambulatoriais com alta prevalência de doença aterosclerótica e de cardiopatia. MÉTODOS: Estudo transversal. Critérios de inclusão: pacientes ambulatoriais com idade > 50 anos, encaminhados para realização de eletrocardiograma (ECG). Critérios de exclusão: indivíduos que não aceitaram participar de um estudo sobre a prevalência da resposta cardioinibitória à MSC, pacientes com demência, portadores de marca-passo, indivíduos com sopro carotídeo ou com história de AVC ou IAM nos últimos 3 meses. A MSC foi realizada na posição supina durante 10 segundos. Foram consideradas complicações da MSC a ocorrência de arritmias sustentadas e o aparecimento de déficit neurológico durante a MSC ou nas primeiras 24 horas após o seu término. RESULTADOS: Foram selecionados aleatoriamente 562 pacientes de um total de 1.686 indivíduos com critérios de inclusão. Sessenta indivíduos apresentaram critérios de exclusão. Os 502 pacientes restantes (52 por cento homens, idade média de 65 anos, 69 por cento cardiopatas e 50 por cento com doença aterosclerótica) foram submetidos a 1.053 MSC. Dois pacientes apresentaram complicações (0,4 por cento; IC95 por cento:0 por cento-0,9 por cento). Um homem de 71 anos apresentou monoparesia do braço esquerdo com regressão completa em 30 minutos. Outro homem, de 56 anos, apresentou hemianopsia homônima à esquerda que regrediu em 7 dias. CONCLUSÃO: A incidência de complicações relacionadas à MSC foi pequena, particularmente quando se considerou que a população submetida à manobra era idosa e com alta prevalência de cardiopatia estrutural e de doença aterosclerótica.

BACKGROUND: The carotid sinus massage (CSM) is a simple and low-cost technique with many indications. OBJECTIVE: To determine the safety of CSM in outpatients with high prevalence of atherosclerotic disease and cardiopathy. METHODS: A transversal study. Inclusion criteria: Outpatients aged >50 years, referred for ECG. Exclusion criteria: Individuals that refused to participate in a study on the prevalence of the cardioinhibitory response to CSM, patients with dementia, patients with pacemakers, individuals with carotid murmur or history of stroke or AMI in the last three months. The CSM was carried out in the supine position during 10 seconds. The occurrence of sustained arrhythmias or the occurence of neurological deficit during the CSM or in the first 24 hours after its end were considered complications of the CSM. RESULTS: 562 patients were randomly selected from a total of 1,686 individuals that met the inclusion criteria. Sixty individuals met the exclusion criteria. The remaining 502 patients (52 percent males, 69 percent with cardiopathies and 50 percent with atherosclerotic disease) were submitted to 1,053 CSM. Two patients presented complications (0.4 percent; 95 percentCI:0 percent-0.9 percent). A 71-yr-old man developed left arm monoparesis with complete regression within 30 minutes. Another 56-yr-old man presented left homonymous hemianopsia, with regression after 7 days. CONCLUSION: The incidence of CSM-related complications was small, particularly when considering that the population submitted to the maneuver was elderly, with high incidence of structural heart disease and atherosclerotic disease.

FUNDAMENTO: El masaje del seno carotídeo (MSC) es una técnica simple, de bajo costo y con muchas indicaciones. OBJETIVO: Determinar la seguridad del MSC en pacientes ambulatorios con alta prevalencia de enfermedad aterosclerótica y cardiopatía. MÉTODOS: Estudio transversal. Criterios de inclusión: pacientes ambulatorios con edad >50 años, orientados a realizar el electrocardiograma (ECG). Criterios de exclusión: individuos que no aceptaron participar de un estudio sobre la prevalencia de la respuesta cardioinhibitoria al MSC; pacientes con demencia; portadores de marcapaso; individuos con soplo carotídeo o historia de ACV o IAM en los últimos 3 meses. Se realizó el MSC en posición supina durante 10 segundos. Se consideraron complicaciones del MSC: la ocurrencia de arritmias sostenidas y el aparecimiento de déficit neurológico, ya sea durante el MSC, ya sea en las 24 horas subsecuentes a su término. RESULTADOS: Se seleccionaron, de modo aleatorio, a 562 pacientes, de un total de 1.686 individuos con los criterios de inclusión. El total de 60 individuos presentaron criterios de exclusión. Los 502 pacientes restantes (el 52 por ciento varones, edad promedio de 65 años, el 69 por ciento cardiópatas y el 50 por ciento con enfermedad aterosclerótica) se sometieron a 1.053 MSC. La cantidad de dos pacientes presentaron complicaciones (0,4 por ciento; IC95 por ciento:0 por ciento-0,9 por ciento). Un varón de 71 años presentó monoparesia del brazo izquierdo con regresión completa en 30 minutos. Otro varón, de 56 años, presentó hemianopsia homónima izquierda, que retrocedió en 7 días. CONCLUSIÓN: La incidencia de complicaciones relacionadas al MSC resultó pequeña, particularmente cuando se consideró que la población sometida a la maniobra era anciana y con alta prevalencia tanto de cardiopatía estructural como de enfermedad aterosclerótica.

Acute and chronic electrical activation of baroreceptor afferents in awake and anesthetized subjects

Electrical stimulation of baroreceptor afferents was used in the 1960's in several species, including human beings, for the treatment of refractory hypertension. This approach bypasses the site of baroreceptor mechanosensory transduction. Chronic electrical stimulation of arterial baroreceptors, particularly of the carotid sinus nerve (Hering's nerve), was proposed as an ultimate effort to treat refractory hypertension and angina pectoris due to the limited nature of pharmacological therapy available at that time. Nevertheless, this approach was abandoned in the early 1970's due to technical limitations of implantable devices and to the development of better-tolerated antihypertensive medications. More recently, our laboratory developed the technique of electrical stimulation of the aortic depressor nerve in conscious rats, enabling access to hemodynamic responses without the undesirable effect of anesthesia. In addition, electrical stimulation of the aortic depressor nerve allows assessment of the hemodynamic responses and the sympathovagal balance of the heart in hypertensive rats, which exhibit a well-known decrease in baroreflex sensitivity, usually attributed to baroreceptor ending dysfunction. Recently, there has been renewed interest in using electrical stimulation of the carotid sinus, but not the carotid sinus nerve, to lower blood pressure in conscious hypertensive dogs as well as in hypertensive patients. Notably, previous undesirable technical outcomes associated with electrical stimulation of the carotid sinus nerve observed in the 1960's and 1970's have been overcome. Furthermore, promising data have been recently reported from clinical trials that evaluated the efficacy of carotid sinus stimulation in hypertensive patients with drug resistant hypertension.

Inhibition of rhynchophylline on carotid sinus baroreceptor activity in anesthetized rats / 中国药理学与毒理学杂志

AIM To elucidate the effect of rhynchophylline(Rhy) on carotid sinus baroreceptor activity (CBA). METHODS By recording sinus nerve afferent discharge activity with isolated carotid sinus perfusion, parameters of CBA, such as peak slope (PS), peak integral value (PIV), threshold pressure (TP) and saturation pressure (SP) were examined. ①Rhy 10, 50, and 100 μmol·L-1, dissolved in K-H solution, was perfused into isolated carotid sinus, then the effects of Rhy on parameters of CBA were observed while intrasinus pressure was altered in a stepwise manner. ②NG-nitro-L-arginine methyl ester (L-NAME) 10 mmol·L-1, tetraethylammonium (TEA) 1 mmol·L-1 and Bay K8644 500 nmol·L-1 were perfused into isolated carotid sinus, and effects of them on the response of carotid baroreceptor to Rhy were observed. RESULTS ① By perfusing the isolated carotid sinus with Rhy 10 μmol·L-1, PS decreased from (19.2±0.3)% to (18.2±0.1)%·kPa-1and the PIV decreased from (219.3±3.3)% to (199.1±3.8)%, while TP and SP increased from (8.2±0.3) to (9.1±0.1)kPa and (21.5±0.1) to (22.1±0.1)kPa, respectively. By perfusing with Rhy 50 and 100 μmol·L-1, the changes in PS, TP and SP were in concentration-dependent manner, and this indicated inhibitory effect of Rhy on CBA. ②Pretreatment with L-NAME 100 μmol·L-1 did not affect inhibitory action of Rhy 50 μmol·L-1 on CBA. ③Pretreatment with TEA 1 mmol·L-1 had no effect on inhibitory effect of Rhy 50 μmol·L-1 on CBA. ④Pretreatment with Bay K8644 500 nmol·L-1 could mostly attenuate effect of Rhy 50 μmol·L-1 on CBA. CONCLUSION Rhy inhibits CBA via blocking calcium influx in baroreceptor nerve ending.

A Novel Rabbit Carotid Body and Common Carotid Artery Model in Vivo for the Simulation of Various Intermittent and Continuous Hypoxia Modes / 中国呼吸与危重监护杂志

Objective To develope a novel rabbit carotid body and carotid common artery model in vivo for the simulation of various intermittent hypoxia (IH) intensities, IH durations, IH reoxygenation (ROX) durations and continuous hypoxia (CH) modes.Methods Forty-five adult New Zealand rabbits (2.5～3.0 kg) were anesthetized while spontaneous breathing kept intact.The tissue surrounding the fight earetid common artery and carotid sinus nerve (CSN) were cleared and "single" chemoreceptor bundle of the CSN was revealed.Then suction electrodes were placed and CSN afferent activity was monitored and recorded carefully.The fight common carotid artery was exposed, cannulated to distal part and its proximal part was ligated.Preparations were challenged by changing the PO2 of the gas mixture equilibrating the perfusate.Alternatively perfusion (2 mL/min) of equilibrated porfusate bubbled with normoxia or hypoxia gas mixtures formed IH/ROX cycles in carotid common artery,simulating the pattern of hypoxic episodes seen in obstructive sleep apnea syndrome (OSAS), or with continuously perfusing hypoxia perfusate to form CH modes.All the perfusing procedures were regulated by a customized computer-controlled set and monitored using O2 gas analyzer.After the systematic exposures, carotid body, carotid common artery part distal to cannula,and carotid bifurcation were harvested as samples.Results The frequencies and average amplitudes of CSN chemoreceptor bundles afferent activities with normoxia peffusion were (0.17±0.03) impulse/s and (46.2±4.4) μV, and with hypoxia perfusion were (0.6±0.09) impulse/s and (87.4±6.6) μV, respectively.PO2 was (139±1.5) nun Hg in normoxia perfusate and (35.2±1.3) mm Hg in hypoxia perfusate.Conclusion This new carotid body and carotid common artery model is a valuable tool to study neurological and biochemical changes in various IH and CH modes.