Week 5 - Lesson 1 (Part 1) Flashcards
What are 5 characteristics of the low pulsatility?
- Broad systolic peak
- Forward flow throughout diastole
- Completely above or below the baseline
- this is dependent on the direction of flow - Low peripheral resistance flow
- Monophasic waveform
- all of the flow is above the baseline
What are 3 examples of low peripheral resistance flow?
- ICA
- Vertebral
- Renal arteries
How do you measure the intima layer of the ICA?
The inner most line (hyperechoic) to the outer part of the tunica layer (hypoechoic)
- dont include the third layer
What is a good indication that there could be carotid disease?
The thickening of the intima layer over time
Where does more plaque/problems occur in the ICA?
Bulb/bifurcation
What are 4 characteristics of moderate pulsatility?
- Tall and sharp systolic peak
- Forward flow during all of diastole
- Diastolic flow is relatively less than is seen in low pulsatility waveforms
- a result of moderate peripheral resistance - Biphasic flow
- a single antegrade and a single retrograde wave in the cardiac cycle
What are examples of where you see moderate pulsatility flow? (3)
- External carotid artery
- supplies the face and neck - Common carotid artery
- SMA
- during fasting
What is a normal finding in moderate pulsatility?
Dicrotic notch
What does a dicrotic notch represent?
Closure of the aortic valve
What happens with closure of the aortic valve? (2)
- Temporary cessation of forward flow
2. Followed by resumption of forward flow driven by the elastic rebound of the arterial wall
What is the dicrotic notch?
It is the transition from systole to diastole
What are 4 characteristics of high pulsatility?
- Narrow, tall, sharp systolic peaks
- Followed by a brief flow reversal
- Then a brief forward flow
- Triphasic waveform
- flow in systole is above the baseline, then a reversed segment in diastole below the baseline and a third component of diastolic flow above the baseline
Where is high pulsaility flow seen?
In peripheral arteries in the resting state
- arms and legs
What are the characteristics of the common carotid artery? (4)
- Moderate pulsatility
- Close to the baseline
- Low diastolic flow
- Sharp upstroke
What are the characteristics of the internal carotid artery? (6)
- Lower pulsatility
- Rounded peak
- broader - Windows
- High diastolic flow
- Hover over the baseline
- More lateral
What are the characteristics of the external carotid artery? (6)
- Higher pulsatility than ICA
- Sharper peaks
- higher upstroke - Small to no windows
- Relatively lower diastolic flow
- Touching the baseline
- More medial
What are the characteristics of the vertebral arteries? (4)
- Low pulsatility
- similar to the ICA with lower velocity - Forward flow throughout diastole
- Windows
- Hover over baseline
How does the vertebral artery travel?
Travels cephalad through the transverse foramina of C6 to C2
What are the characteristics of the subclavian artery? (7)
- High pulsatility
- High resistant signal
- Sharp systolic upstroke
- Triphasic signal
- Reverse diastolic component
- Forward diastolic component
- No window
Where is the subclavian artery located?
Posterior to the clavicle
What are the characteristics of monophasic arterial flow? (3)
- Spectrum is completely above or below the baseline
- Both systolic and diastolic portions
- Continuous flow
Antigrade
Monophasic flow above the baseline
Retrograde
Monophasic flow below the baseline
What is a good example of monophasic flow?
Low resistant ICA flow
What are the characteristics of biphasic arterial flow? (3)
- Spectrum has all systolic portion above the baseline
- The diastolic flow crosses the baseline
- below it (negative) - High resistant flow pattern
What is a good example of biphasic arterial flow?
Abnormal triphasic waveform (suppose to be tri but appears as bi)
- pathology
What are the characteristics of triphasic arterial flow? (4)
- The systolic phase is above the baseline
- The first diastolic component is below the baseline
- The third component of diastolic flow is above the baseline
- High resistant flow patterns
What is a good example of triphasic arterial flow? (2)
- Subclavian arteries
2. Femoral arteries
How can you indicate abnormal flow patterns?
When the flow pattern that is normally seen in a specific vessel changes
What are indicators of abnormal flow patterns? (3)
- Approaching stenosis
- Stenosis
- Post stenosis
