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.

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.

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.

Crossense em paciente portador de marcapasso por hipersensibilidade do seio carotídeo / Far-field in patient with pacemaker due to carotid sinus hypersensitivity

Relata-se o caso de um paciente portador de marcapasso dupla-câ- mara, implantado por hipersensibilidade do seio carotídeo, que, em consulta ambulatorial, manifestou reaparecimento tardio dos sintomas que apresentava antes do implante do dispositivo. Após descartar alterações de limiares, sensibilidade ou impedância do sistema de estimulação cardíaca, foi realizada massagem do seio carotídeo e evidenciada inibição inadequada da estimulação ventricular. A radiografia de tórax revelou tratar-se de cabo-eletrodo ventricular posicionado em região látero-basal do ventrículo esquerdo via seio coronário. O problema foi corrigido com ajustes dos parâmetros, devidamente comprovado com a não reprodutibilidade do evento

We report the case of a patient with a dual-chamber pacemaker for carotid sinus hypersensitivity who, at an outpatient visit, presented a late resumption of the symptoms observed before the implantation of the device. After discarding threshold, sensitivity or impedance changes of the cardiac stimulation system, carotid sinus massage was performed and inadequate ventricular pacing inhibition was evidenced. A chest X-ray showed the ventricular lead had been placed at the laterobasal region of left ventricle through the coronary sinus. The problem was corrected by adjusting the parameters, and this was confirmed by a discontinuation of the event

Cuerpo carotídeo: un enfoque anatómico y fisiológico / Carotid body: an anatomical and physiological approach

Resumen:Este trabajo describe la presencia del cuerpo carotídeo y su relación con el seno carotídeo. Además, se presenta una revisión bibliográfica de la historia, anatomía y fisiologia del órgano y su importancia como quimioreceptor del cuerpo humano.

Abstract:This work describes the presence of carotid body and its relationship to the carotid sinus. In addition, a literature review of the history, anatomy and physiology of the body and its importance as chemoreceptory the human body is presented.

Improved methods for researching isolated carotid sinus baroreceptors automatically controlling for sinus pressure / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To develop a system for automatically controlling carotid sinus pressure in the study on baroreceptors.</p><p><b>METHODS</b>The preparation containing carotid sinus with parts of the connected vessels and carotid sinus nerve (CS-CSN) were isolated and perfused. A critical pressure controlling component (PRE-U, Hoerbiger, Deutschland) dictated by a computer was integrated into the system to clamp the intrasinus pressure. The pressure command and the relevant intrasinus pressure were compared to evaluate the validity of the pressure controlling system.</p><p><b>RESULTS</b>A variety of sinus pressure-controlling patterns, including pulsation, ramp and step pressures, could be achieved accurately by using the system, and the pressure-dependent discharge activities of sinus nerve were confirmed.</p><p><b>CONCLUSION</b>This system for clamping carotid sinus pressure could realize multiple pressure-controlling patterns and is a useful and flexible pressure controlling method that could applied in the study on mechano-electric transduction of baroreceptors.</p>

Involvement of cross interaction between central cholinergic and histaminergic systems in the nucleus tractus solitarius in regulating carotid sinus baroreceptor reflex / 生理学报

The carotid sinus baroreceptor reflex (CSR) is an important approach for regulating arterial blood pressure homeostasis instantaneously and physiologically. Activation of the central histaminergic or cholinergic systems results in CSR functional inhibitory resetting. However, it is unclear whether two systems at the nucleus tractus solitarius (NTS) level display cross interaction to regulate the CSR or not. In the present study, the left or right carotid sinus region was isolated from the systemic circulation in Sprague-Dawley rats (sinus nerve was reserved) anesthetized with pentobarbital sodium. Respective intubation was conducted into one side isolated carotid sinus and into the femoral artery for recording the intracarotid sinus pressure (ISP) and mean arterial pressure (MAP) simultaneously with pressure transducers connection in vivo. ISP was set at the level of 0 mmHg to eliminate the effect of initial internal pressure of the carotid sinus on the CSR function. To trigger CSR, the ISP was quickly elevated from 0 mmHg to 280 mmHg in a stepwise manner (40 mmHg) which was added at every step for over 4 s, and then ISP returned to 0 mmHg in similar steps. The original data of ISP and corresponding MAP were fitted to a modified logistic equation with five parameters to obtain the ISP-MAP, ISP-Gain relationship curves and the CSR characteristic parameters, which were statistically compared and analyzed separately. Under the precondition of no influence on the basic levels of the artery blood pressure, the effects and potential regulatory mechanism of preceding microinjection with different cholinoceptor antagonists, the selective cholinergic M1 receptor antagonist, i.e., pirenzepine (PRZ), the M2 receptor antagonist, i.e., methoctramine (MTR) or the N1 receptor antagonist, i.e., hexamethonium (HEX) into the NTS on the changes in function of CSR induced by intracerebroventricular injection (i.c.v.) of histamine (HA) in rats were observed. Meanwhile, the actions and possible modulatory mechanism of preceding microinjection with different histaminergic receptor antagonists, the selective histaminergic H1 receptor antagonist, i.e., chlorpheniramine (CHL) or the H2 receptor antagonist, i.e., cimetidine (CIM) into the NTS on the changes in function of CSR resulted from the i.c.v. cholinesterase inhibitor, physostigmine (PHY) were also examined in order to confirm and to analyze effects of cross interaction between central histaminergic and cholinergic systems on CSR. The main results obtained are as follows. (1) Standalone microinjection of different selective cholinergic receptor antagonists (PRZ, MTR or HEX) or different selective histaminergic receptor antagonists (CHL or CIM) into the NTS with each given dose had no effects on the CSR function and on the basic levels of the artery blood pressure, respectively (P > 0.05). (2) The pretreatment of PRZ or MTR into the NTS with each corresponding dose could attenuate CSR resetting resulted from i.c.v. HA in some degrees, which remarkably moved the posterior half range of ISP-MAP relationship curve downwards (P < 0.05), shifted the middle part of ISP-Gain relationship curve upwards (P < 0.05), and increased reflex parameters such as the MAP range and maximum gain (P < 0.05), but decreased parameters such as saturation pressure and intracarotid sinus pressure at maximum gain (P < 0.05). The catabatic effects of pretreatment with MTR into the NTS on CSR resetting induced by i.c.v. HA were more obvious than those with PRZ (P < 0.05), but pretreatment of HEX with given dose into the NTS had no effects on CSR resetting induced by i.c.v. HA (P > 0.05). (3) The effects of pretreatment of CHL or CIM into the NTS with each corresponding dose on CSR resetting made by i.c.v. PHY were similar to those of pretreatment of PRZ or MTR into the NTS on CSR resetting resulted from i.c.v. HA, and the decreasing effects of pretreatment with CHL into the NTS on CSR resetting induced by i.c.v. PHY were more remarkable than those with CIM (P < 0.05). These findings suggest that CSR resetting resulted from either HA or PHY into the lateral ventricle may partly involve the descending histaminergic or cholinergic pathway from the hypothalamus to NTS, which might evoke a cross activation of the cholinergic system in the NTS, via cholinergic M1 and M2 receptors mediation, especially the M2 receptors showing actions, or trigger another cross activation of the histaminergic system in the NTS, by histaminergic H1 and H2 receptors mediation, especially the H1 receptors displaying effects.

Prueba de inclinación, Head-up tilt test, lecciones aprendidas en 564 casos consecutivos / Head-up tilt test, lessons learned from 564 consecutive cases

Introducción. El síncope es un motivo frecuente de consulta; el mecanismo causal más común es el reflejo, que incluye el síncope neurocardiogénico, SN, la hipotensión ortostática, la hipersensibilidad del seno carotídeo, entre otros. Estas variantes se valoran mediante la prueba de inclinación, con o sin estímulo farmacológico con nitroglicerina. El presente estudio recoge la experiencia con este examen auxiliar realizado en nuestro centro en los últimos 8 años. Material y métodos. Es un estudio retrospectivo, en el que se analizaron los resultados de las pruebas de inclinación realizadas a los pacientes que fueron referidos consecutivamente a nuestro centro en el período julio 2003 - agosto 2010. La información se obtuvo de la base de datos electrónica, así como del interrogatorio de los síntomas que motivaron la solicitud de la prueba. Resultados. Se incluyeron los datos de 564 pruebas de inclinación; la edad promedio fue 36.33 más menos 18.4 años, 6-89, a predominio el sexo femenino, 373, hombres 191. El motivo de realización de la prueba fue: historia de síncope, 67 por ciento, lipotimia, 26 por ciento, y otros. El examen fue anormal en 470 pacientes, 92 negativos, sensibilidad global 83.6, y los diagnósticos fueron: 118 SN tipo vasodilatador, 25 por ciento, 112 SN tipo cardioinhibitorio, 24 por ciento, y 157 SN de tipo mixto, 33 por ciento; 60 pacientes presentaron taquicardia postural ortostática, 12 por ciento, y 24 hipotensión ortostática, 5 por ciento, 9 de los cuales tenía tratamiento farmacológico antihipertensivo; edad promedio 64 años. En 11 pacientes, 2.3 por ciento, se documentó hipersensibilidad del seno carotídeo, 9 de los cuales presentó también alguna forma de SN, edad promedio 60.63 años. Conclusión. La prueba de inclinación es adecuadamente sensible para la valoración del paciente que se presenta con síncope, en especial, en pacientes jóvenes sin evidencia de cardiopatía estructural. El SN es la disautonomía más frecuente y es más prevalente en mujeres pero más pronunciado en hombres, mientras que la hipotensión ortostática y la hipersensibilidad del seno carotídeo predomina en personas mayores.

Cough-Induced Syncope in a Patient with Bronchial Asthma / 대한간질학회지

Cough-induced syncope is belongs to the heterogeneous group of situational syncope. It is characterized by the loss of consciousness occurring after excessive coughing. A 63-year-old man complained of cough syncope for 15 days. During vigorous coughing, he lost consciousness for a few seconds. He had past medical history of bronchial asthma and diabetes mellitus. Various tests for syncope including electroencephalogram, electrocardiogram, 24-hours Holter monitoring, echocardiogram, carotid sinus massage, tilt table test, carotid duplex, and brain MRI were normal. He was treated successfully with anti-tussives and bronchodilators. We report a case of cough-induced syncope in a patient with bronchial asthma.

Cough-Induced Syncope in a Patient with Bronchial Asthma

Cough-induced syncope is belongs to the heterogeneous group of situational syncope. It is characterized by the loss of consciousness occurring after excessive coughing. A 63-year-old man complained of cough syncope for 15 days. During vigorous coughing, he lost consciousness for a few seconds. He had past medical history of bronchial asthma and diabetes mellitus. Various tests for syncope including electroencephalogram, electrocardiogram, 24-hours Holter monitoring, echocardiogram, carotid sinus massage, tilt table test, carotid duplex, and brain MRI were normal. He was treated successfully with anti-tussives and bronchodilators. We report a case of cough-induced syncope in a patient with bronchial asthma.

Hypotensive bradycardic events during shoulder arthroscopic surgery under interscalene brachial plexus blocks / 대한마취과학회지

Sudden, profound hypotensive and bradycardic events (HBEs) have been reported in more than 20% of patients undergoing shoulder arthroscopy in the sitting position. Although HBEs may be associated with the adverse effects of interscalene brachial plexus block (ISBPB) in the sitting position, the underlying mechanisms responsible for HBEs during the course of shoulder surgery are not well understood. The basic mechanisms of HBEs may be associated with the underlying mechanisms responsible for vasovagal syncope, carotid sinus hypersensitivity or orthostatic syncope. In this review, we discussed the possible mechanisms of HBEs during shoulder arthroscopic surgery, in the sitting position, under ISBPB. In particular, we focused on the relationship between HBEs and various types of syncopal reactions, the relationship between HBEs and the Bezold-Jarisch reflex, and the new contributing factors for the occurrence of HBEs, such as stellate ganglion block or the intraoperative administration of intravenous fentanyl.

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.

Effect of carotid and aortic baroreceptors on cardiopulmonary reflex: the role of autonomic function

We determined the sympathetic and parasympathetic control of heart rate (HR) and the sensitivity of the cardiopulmonary receptors after selective carotid and aortic denervation. We also investigated the participation of the autonomic nervous system in the Bezold-Jarish reflex after selective removal of aortic and carotid baroreceptors. Male Wistar rats (220-270 g) were divided into three groups: control (CG, N = 8), aortic denervation (AG, N = 5) and carotid denervation (CAG, N = 9). AG animals presented increased arterial pressure (12 percent) and HR (11 percent) compared with CG, while CAG animals presented a reduction in arterial pressure (16 percent) and unchanged HR compared with CG. The sequential blockade of autonomic effects by atropine and propranolol indicated a reduction in vagal function in CAG (a 50 and 62 percent reduction in vagal effect and tonus, respectively) while AG showed an increase of more than 100 percent in sympathetic control of HR. The Bezold-Jarish reflex was evaluated using serotonin, which induced increased bradycardia and hypotension in AG and CAG, suggesting that the sensitivity of the cardiopulmonary reflex is augmented after selective denervation. Atropine administration abolished the bradycardic responses induced by serotonin in all groups; however, the hypotensive response was still increased in AG. Although the responses after atropine were lower than the responses before the drug, indicating a reduction in vagal outflow after selective denervation, our data suggest that both denervation procedures are associated with an increase in sympathetic modulation of the vessels, indicating that the sensitivity of the cardiopulmonary receptors was modulated by baroreceptor fibers.

Renin angiotensin system and cardiac hypertrophy after sinoaortic denervation in rats

OBJECTIVE: The aim of this study was to evaluate the role of angiotensin I, II and 1-7 on left ventricular hypertrophy of Wistar and spontaneously hypertensive rats submitted to sinoaortic denervation. METHODS: Ten weeks after sinoaortic denervation, hemodynamic and morphofunctional parameters were analyzed, and the left ventricle was dissected for biochemical analyses. RESULTS: Hypertensive groups (controls and denervated) showed an increase on mean blood pressure compared with normotensive ones (controls and denervated). Blood pressure variability was higher in denervated groups than in their respective controls. Left ventricular mass and collagen content were increased in the normotensive denervated and in both spontaneously hypertensive groups compared with Wistar controls. Both hypertensive groups presented a higher concentration of angiotensin II than Wistar controls, whereas angiotensin 1-7 concentration was decreased in the hypertensive denervated group in relation to the Wistar groups. There was no difference in angiotensin I concentration among groups. CONCLUSION: Our results suggest that not only blood pressure variability and reduced baroreflex sensitivity but also elevated levels of angiotensin II and a reduced concentration of angiotensin 1-7 may contribute to the development of left ventricular hypertrophy. These data indicate that baroreflex dysfunction associated with changes in the renin angiotensin system may be predictive factors of left ventricular hypertrophy and cardiac failure.

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.