Carotids Flashcards
A pt with amaurosis fugax in the left eye is likely to be from carotid disease from contralateral carotid arteries?
False
What percent of pt who have had a TIA will have a full blown stroke if untreated?
20%
What is the surgical treatment for occluded ICA if the vertebral are still patent
No surgical intervention
What are most likely types of stroke
15% Haemorrhagic
85% embolic
Difference between left and right arteries coming off the aorta
Left has separate subclavian and common carotid
Right has brachiocephalic that bifurcates into common carotid and subclavian
What percentage of embolic strikes are of cardiac cause
15-30%
What percentage of stroke is due to carotid disease
50%
Difference between TIA and stroke
TIA is transient and lasts less than 24hours (most less than 1 hour)
What side of the body does a right sided stroke effect
Left carotids
What side is carotid disease for Right sided infarct (in brain)
Right carotid
Symptoms of vertebro-basilar disease
Dizzy, no balance
What are the risk factors?
Same as CAD and PAD
Management of stenosis and reducing stroke risk
Surgery or stenting plus medical therapy
Assessment for carotid stenosis
Ultrasound plus either CTA OR MRA
Which arteries are suitable for ultrasound? Regarding strokes
Carotid arteries
Vertebral arteries
Subclavian
Describe waveforms of normal carotid arteries
Always flowing in one direction, always above zero line
How to grade stenosis in carotid arteries?
Use velocity
Absolute velocity values and ratios between sides are compared with data to grade stenosis
What to measure to grade stenosis in ICA
Measure EDV and PSV in internal and carotid arteries (4 measurements in total)
And ICA to CCA PSV ratio
How to calculate ratios for grading stenosis?
Peak systolic velocity (ICA PSV / CCA PSV)
St Mary’s Ratio (ICA PSV / CCA EDV)
What does hyperechoic mean
Bright
Hypoechoic = dark
What is the use of B mode for in carotids
Describe images but no measurements
How will the CCA waveform look if the ICA is fully occluded
Diastolic flow will drop to zero as blood not going through the distal part of the artery (ICA)
NICE guidelines for carotid imaging
Everyone with TIA considered candidate for endararectomy should have urgent carotid imaging
What percentage stenosis should be treated surgically?
> 50% in symptomatic patients
