Fluid Dynamics Part 2 Flashcards
What are the parts of the waveform?
A Early Systole B Peak Systolic C Late Systole D Early Diastole E Late Diastole
What is systole flow?
Blood pressure has built up in left ventricle
Forward flow through the aorta & other arteries
What is peak systole?
Maximum ventricular contraction and blood pushed to its peak
What is late systole?
reversal of flow
What is diastole?
Flow moves forward-a coming out of late systole until it hits the pressure of the next oncoming wave and then reverses direction
Diastole is characteristic of blood supplying low resistant beds
Where are these branches going?
Depending on what the branches of the aorta are feeding they will produce a certain type of waveform
All arterial waveforms are somewhat alike but depending on whether they are feeding a high or low resistance organ will have different wave form
What is low resistance?
Low resistance organs – have lots of blood flow – do not resist blood coming in
Liver, kidney and spleen
Fed by suprarenal branches which would be the celiac, splenic, and hepatic
Also renal arteries are low resistance because feeding the kidneys
What is high resistance?
High resistance organs – not as needy for blood, resist some blood flow
Stomach, small intestines- changes when we eat
Fed by SMA
Small intestines and stomach
IMA also because it feeds the GI system which is high resistance
What are examples of low resistance?
Forward, steady, continuous flow Dilated vascular bed ICA Vertebral Renal Celiac Splenic Hepatic
What are examples of high resistance?
Pulsatile, reversal component Triphasic or biphasic ECA Subclavian Aorta Iliac Extremities SMA - fasting
What do low resistance waveforms look like?
Systolic peak followed by a diastolic forward flow waveform
What is the number one characteristic of low resisitive waveform?
Number one characteristics of a low resistance waveform is the diastolic component (forward flow)
High end diastolic meaning above the baseline.
What do high resistance waveforms look like?
Triphasic – systole, reversed flow and absence or very little forward diastolic flow
What is vasodilation? and examples
Vasodilation – decreases flow reversal in small and medium vessels
Exercise
Heat
Pathological states – distal to stenosis and proximal to stenosis due to increased resistance and arteriovenous fistulas
What is vasoconstriction?
Vasoconstriction – increases flow reversal in small and medium vessels
Cold
What happens when you exercise?
Most effective method for vasodilation Vessels becomes larger Resistance decreases Perfusion increases Decreases flow reversal
What questions to ask for patients who present with vasodilation?
Has your patient exercised recently?
Has your patient been in warm temperatures?
What are the normal Doppler waveforms?
What happens proximal to a stenosis?
Waveform is dampened
Not disturbed
tardus parvus waveform
What happens at the stenosis?
At level of stenosis
Higher velocities
Pressure decreases
Disorganized flow
What happens distal to stenosis?
Distal to stenosis
Post stenotic turbulence
Disturbed/chaotic flow
Bidirectional
What are collaterals?
Collateral flow taking over for stenosis or occlusion
Flow is present but possibly not normal for site
Increased volume
Increased velocity
Waveform changes
Reversed flow
