Carotid sinus syncope

(noun)

The carotid sinus can be oversensitive to manual stimulation, a condition known as carotid sinus hypersensitivity, carotid sinus syndrome or carotid sinus syncope, in which manual stimulation causes large changes in heart rate and/or blood pressure. This classically presents as a patient who has "fainted" on several occasions while shaving, or in some other way coming into contact with their carotid sinus.

Related Terms

Examples of Carotid sinus syncope in the following topics:

  • Carotid Sinus Syncope and Massage

    • The carotid sinus often has atherosclerotic plaques.
    • Massage of the carotid sinus, or carotid sinus massage, is used to diagnose carotid sinus syncope.
    • The carotid sinus can also be oversensitive to carotid sinus massage.
    • This condition is called carotid sinus syncope, and results in dramatic changes in heart rate or blood pressure.
    • Carotid sinus syncope sometimes accompanies convulsive seizures because of the intensity of the carotid sinus reflex when pressure builds in one or both carotid sinuses.

  • Glossopharyngeal (IX) Nerve

    • It receives visceral sensory fibers from the carotid bodies, carotid sinus.
    • Visceral sensory (general visceral afferent): Carries visceral sensory information from the carotid sinus and body.

  • Abducens (VI) Nerve

    • At the tip of the petrous temporal bone, it makes a sharp turn forward to enter the cavernous sinus.
    • In the cavernous sinus it runs alongside the internal carotid artery.
    • For example, fractures of the petrous temporal bone can selectively damage the nerve, as can aneurysms of the intracavernous carotid artery.

  • Veins of the Head and Neck

    • Formed at the base of the brain from the inferior petrosal sinus and the sigmoid sinus, the internal jugular vein runs down the side of the neck adjacent to the internal carotid artery.

  • Vagus (X) Nerve

    • Upon leaving the medulla between the medullary pyramid and the inferior cerebellar peduncle, it extends through the jugular foramen, then passes into the carotid sheath between the internal carotid artery and the internal jugular vein below the head, to the neck, chest and abdomen, where it contributes to the innervation of the viscera.
    • Excessive activation of the vagal nerve during emotional stress can also cause vasovagal syncope due to a sudden drop in cardiac output, causing cerebral hypoperfusion.

  • Oculomotor (III) Nerve

    • Sympathetic postganglionic fibers also join the nerve from the plexus on the internal carotid artery in the wall of the cavernous sinus and are distributed through the nerve, for example, to the smooth muscle of levator palpebrae superioris.
    • It then runs along the lateral wall of the cavernous sinus, above the other orbital nerves, receiving in its course one or two filaments from the cavernous plexus of the sympathetic nervous system, and a communicating branch from the ophthalmic division of the trigeminal nerve.

  • Development of the Cardiovascular System

    • The infraorbital and mandibular branches arise from a common stem, the terminal part of which anastomoses with the external carotid.
    • The third aortic arch constitutes the commencement of the internal carotid artery, and is named the carotid arch.
    • The fourth left arch constitutes the arch of the aorta between the origin of the left carotid artery and the termination of the ductus arteriosus.
    • The human venous system develops mainly from the vitelline,umbilical, and cardinal veins, all of which empty into the sinus venosus.

  • Cerebrovascular Accident

    • Selected patients may benefit from carotid endarterectomy and the use of anticoagulants.
    • Two types of thrombosis can cause stroke: large vessel disease involves the common and internal carotids, vertebral, and the Circle of Willis.
    • Cerebral venous sinus thrombosis leads to stroke due to locally increased venous pressure, which exceeds the pressure generated by the arteries.

  • Congestive Heart Failure

    • This destimulates baroreceptors in the carotid sinus and aortic arch which links to the nucleus tractus solitarius.