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