Anatomy and Cerebral Circulation of the Rat
Yanlin Wang-Fischer in Manual of Stroke Models in Rats, 2008
The distributions of nerves and nerve-related sensors in rats are similar to those in the human.3 The carotid sinus is a slight dilation in the carotid artery at its bifurcation into the external and internal carotid arteries: It contains baroreceptors (pressure sensors), which detect vasodilation and thus a decrease in blood pressure. The carotid body is near the bifurcation of the internal carotid artery. It has a chemoreceptor to modulate respiratory and cardiovascular function in response to fluctuations in arterial pH, carbon dioxide, and oxygen concentrations. Its blood supply is from the external carotid artery. The carotid sinus and body are very vascular and abundantly supplied with nerves. The sensory innervations are from the branches of glossopharyngeal and vagus trunks.
Syncope
Stanley R. Resor, Henn Kutt in The Medical Treatment of Epilepsy, 2020
Carotid sinus hypersensitivity is a common finding in older patients. The mechanism of carotid sinus hypersensitivity may be either cardioinhibitory vasodepressor or mixed, but in order to be sure that carotid sinus hypersensitivity is the cause of symptoms of presyncope or syncope, it is imperative to reproduce the patients’ symptoms during carotid sinus massage. Treatment of syncope in patients with carotid sinus hypersensitivity depends upon the predominant mechanism identified. In patients with the predominant cardioinhibitory response, anticholinergic drugs may be considered, although permanent pacing is also effective. When pacing is considered, atrioventricular sequential pacing is often superior to ventricular pacing alone because of the high frequency of pacemaker syndrome encountered with patients with carotid hypersensitivity. Treatment of patients with vasodepressor mixed carotid sinus hypersensitivity is difficult; most patients will require a combination of therapy (see below), and all should be clearly informed beforehand that their symptoms may not be completely alleviated.
Neck Holds
Darrell L. Ross, Gary M. Vilke in Guidelines for Investigating Officer-Involved Shootings, Arrest-Related Deaths, and Deaths in Custody, 2018
While reflex bradycardia has been noted in a number of studies, there have been no reported deaths or bradycardic events to the point of requiring cardiac resuscitation in any of these studies (Arnold, 1999; Berk, Shea, & Crevey, 1991; Kornblum 1986a). Moreover, the medical literature is replete with studies looking at the use of carotid sinus massage as a diagnostic and therapeutic examination tool. In studies of thousands of uses on elderly patients, there were no complications of death or bradycardic events requiring treatment or resuscitation, even though this age group is traditionally more likely to have carotid sinus syndrome and more likely to be symptomatic from carotid sinus stimulation (Pollanen et al., 1998; Reay & Mathers, 1983). In fact, the diagnosis of carotid sinus syndrome, although well written about, is essentially unheard of in patients under the age of 50 years (Brignole & Menozzi, 1992; Coplan & Schweitzer, 1984; Kenny & Richardson, 2001; Mallet, 2003).
The role of carotid ultrasound in patients with non-lateralizing neurological complaints
Published in Hospital Practice, 2023
Shweta Varade, Abinayaa Ravichandran, Erafat Rehim, Hussam Yacoub, Rose Duncan, Hope Kincaid, Megan C. Leary, John Castaldo
While current guidelines address the use of CUS in patients with asymptomatic and symptomatic carotid disease, its utilization in patients with non-lateralizing neurological symptoms or focal neurological symptoms that are non-referable to the carotid artery is not addressed. The goal of our study is to evaluate the benefit of ordering CUS in patients presenting with non-carotid artery-related or other non-lateralizing neurological complaints in The Lehigh Valley Health Network. The large number of patients who undergo CUS testing for a wide variety of neurological complaints in our network provides an ideal cohort to evaluate and meet the objectives of our study. Carotid stenosis, however, can be associated with syncope in patients with carotid sinus hypersensitivity, a mechanism that was not considered in our patients.
Effectiveness and safety of implantable loop recorder and clinical utility of remote monitoring in patients with unexplained, recurrent, traumatic syncope
Published in Expert Review of Medical Devices, 2023
Pietro Palmisano, Federico Guerra, Vittorio Aspromonte, Gabriele Dell’Era, Pier Luigi Pellegrino, Mattia Laffi, Carlo Uran, Silvana De Bonis, Michele Accogli, Antonio Dello Russo, Giuseppe Patti, Francesco Santoro, Antonella Torriglia, Gerardo Nigro, Antonio Bisignani, Giovanni Coluccia, Giulia Stronati, Vincenzo Russo, Ernesto Ammendola
Before ILR insertion, all patients were evaluated by a multidisciplinary team of cardiologists, internists, neurologists and geriatricians, who were experienced in the management of syncope patients; they also underwent an extensive cardiac and neurological work-up in order to establish the etiology of syncope. The initial screening comprised a careful medical history (with description of the last syncopal episode, including the characteristics of syncopal onset and recovery and duration of the event), evaluation of medication, physical examination, resting ECG, two-dimensional echocardiogram and 24 h Holter or >24 h telemetry. The strategy was to continue the diagnostic work-up until the mechanism of syncope was clearly documented. Additional diagnostic procedures, if requested by physicians, were: carotid sinus massage (CSM), active standing test, 24-h ambulatory blood pressure monitoring, head-up tilt test (HUTT) [11], exercise tests, and electrophysiological study (EPS).
Novel approaches: targeting sympathetic outflow in the carotid sinus
Published in Blood Pressure, 2023
Dagmara Hering, Krzysztof Narkiewicz
The importance of sympathetic origin as a critical mechanism underlying hypertension pathophysiology [6] is that emerging therapies have been developed to target sympathetic nervous system activity beyond neural control of the kidney where the RDN approach is specifically applied. Two device-based therapies for hypertension management have been developed to attenuate sympathetic outflow at the level of the carotid sinus. One therapeutic approach includes targeting the carotid body, a chemoreceptor organ that is involved in respiratory and cardiovascular control through complex neural pathways [7]. The second device-based approach is electrical or mechanical stimulation of carotid sinus baroreceptors whose sensitivity is reset in established hypertension, to a higher pressure and reduced in gain, to mediate changes in sympathetic activity to the heart and blood vessels [8].
Related Knowledge Centers
- Arterial Blood
- Baroreceptor
- Blood Pressure
- Carotid Sinus Nerve
- External Carotid Artery
- Internal Carotid Artery
- Reflex
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- Homeostasis
- Body