Carotid Flashcards
6 vessels that make up the circle of willis
MCA, ACA, PCA, ICA, vertebrals, basilar
Four indications for a carotid ultrasound:
stroke/TIA, bruit, trauma, pulsatile neck mass
First branch of the ICA is:
opthalmic artery
ICA has a more ____ location
posterior
ICA originates from the _____
bulb
ICA waveform:
low resistant
1st branch off the ECA
superior thyroid artery
ICA supplies blood to the:
anterior brain, eyes forehead, nose
ECA supplies blood to the:
neck, face, scalp
ECA has a more _____ location
anterior, medial
Ways to differentiate ECA from ICA
ECA has multiple branches, more prominent dicrotic notch, is smaller than the ICA, and has a high resistant waveform.
Located in the wall of the sinus; causes slowing of the heart, vasodilation, and fall in blood pressure
pressoreceptors
Protocol for area of stenosis:
more than one velocity, distal to the site to document disturbed flow, scan through vessel, transverse image for diameter ms., use power doppler
Mild disease classified as:
less than 50% diameter reduction; benefit from therapy
moderate to high end disease classified as
50 - 70 % diameter stenosis; treated medically and follow-up
severe disease classified as
over 70 % diameter reduction; benefit from surgery
ICA/CCA velocity ratio 2 - 4 =
50 - 69% stenosis
ICA/CCA velocity ratio of 4 or greater =
70% and over stenosis
Where should you measure velocity for ICA/CCA ratio
mid - dist CCA; Prox ICA
ICA end diastolic of 40 - 100 cm/s and PSV 125 - 230 cm/s =
50 - 69% stenosis
ICA end diastolic of >100 and PSV >230 cm/s =
80 - 99% stenosis
Risk factors for carotid disease
HTN, diabetes, smoking, family hx, obesity
Criteria for TIA
Symptoms last
Criteria for RIND
symptoms >24 hrs,
Criteria for complete stroke/ CVA
Symptoms >72 hrs, residual effects, usually ischemic
most stroke fatalities from ______
hemorrhagic stroke (blood vessel in head bursts)
Post endarterectomy early occlusion due to thrombus happens:
within 24 - 48 hrs and is extremely urgent.
Post enarterectomy stenosis:
results from neointimal hyperplasia, develops within 12 - 18 months
Differentials for a pulsatile neck mass?
prominent carotid artery, dilated carotid, aneurysm of carotid
may develop from trauma to the neck or secondary to iatrogenic
carotid dissection
fibroplasia of the intima, media, or adventitia of an artery describes
fibromuscular dysplasia (growth of fibrous tissue in wall of artery - causes narrowing)
Fibromuscular dysplasia affects
medium and large arteries, young to middle aged women
Symptoms of fibromuscular dysplasia related to ___
ischemic events
Fibromuscular dysplasia most often affects; second most frequent location?
renal arteries (middle and distal thirds); ICA
Most common cause of renovascular HTN in young adults
fibromuscular dysplasia
May present as cerebral ischemia/TIA and is associated with _______
Fibromuscular dysplasia; cerebral aneurysms
most common type of fibromuscular dysplasia of the ICA
medial fibroplasia (renal). string of beads appearance.
Fibromuscular dysplasia may be associated with
carotid artery dissection
Most FMD lesions occur at
level of 1st/2nd vertebra
flow reducing lesion in the innominate or subclavian artery prox. to the vertebral
subclavian steal
arm with the lowest brachail pressure is the
postive side (w/ subclavian disease)
High blood pressure can cause
plaque to break off and emoblize
Stenosis is described as
narrowing to vessel lumen; usually d/t atherosclerosis
Thin layer of lipid material on intimal layer
fatty streak
accumulation of lipids covered by lips, collagen, elastic fiber deposits
fibroud plaque
contains fibrous tissue, collagen, and calcium
complicated lesion
deterioration of smooth surface of the fibrous cap
ulcerative lesion
Possible causes of cerebrovascular symptoms
carotid artery disease, cardiac arrhythmias, hypotensive episodes
Lower body symptoms for ICA occur on the ____
contralateral side
Rt side hemiparesis means
Lt ICA is suspect
Visual symptoms for ICA occur on the ____
ipsilateral side
Symptoms for ICA lesion
paresis, aphasia, amaurosis fugax
transient loss of vision in one eye
amaurosis fugax
speaking disorder due to brain dysfunction
aphasia
lack of muscular coordination
ataxia
inability to produce clear speech
dysarthria
weakness
paresis
abnormal tingling sensations
paresthesia
Symptomatic patients that benefit most from intervention have
disease of 70 - 99%
Symptomatic patietns with modest benefit from intervention have
50 - 70% disease
With less than 50%, treatment includes
blood thinners and behavior modification
____ is less invasive than carotid endarterectomy
carotid stenting
