Arterial (Quiz 2) Flashcards
What is PAOD (peripheral arterial occlusive disease)?
atherosclerosis of the extremities (virtually always lower) causing ischemia
Is indirect testing subjective or objective?
subjective - works with numbers (quantification)
What are the symptoms of PAOD?
intermittent claudication, rest pain
advanced - thickening of toe hair, skin discoloration/scaliness, evaluation pallor/dependent rubor, ulceration/gangrene, blue toes (may indicate aneurysmal disease)
What is intermittent claudication?
pain in large muscle groups caused by activity
pain must be dscribed as fatigue, cramping, aching, or tiredness
Where does intermittent claudication usually take place?
calf, thigh, or butticks
List the true claudication symptoms.
relieved with quiet standing, easily reproducible with same amount of activity
(site of symptoms occurs distal to site of disease)
What are diseases that may mimic claudication?
spinal stenosis, herniated disk, osteoarthritis
If pain is variable, is it intermittent claudication?
no
With intermittent claudication, describe why there is leg pain with activity.
if blockage is in leg arteries, it compensates and dilates distal to the blockage-
once walking, compensation will not be enough; once the threshold is reached, pain starts
Why is there rest pain with claudication?
due to gravity not helping push blood through vessels
What is the overall purpose of the vascular laboratory in patients with lower extremity PAD?
In other words, what will the results of the test tell you?
severity, location, and the hemodynamic significance
List historical symptoms (from taking patient history) consistent with peripheral disease.
coexisting conditions such as stroke, transient ischemic attack (TIA), coronary artery disease (CAD), hypertension, diabetes, lipid disorders, smoking history, family cardiac/peripheral vascular history
the more of these symptoms, the more likely they are to have the disease
How should the patient be positioned when doing a peripheral test?
leg externally located, patient flat as possible, supine
What are the components of physiologic testing?
Doppler pulses, segmental pressures, plethysmographic waveforms, digital PPG waveform and pressure
What position should you be in if you want the best Doppler signal?
45 degree angle to flow
List the order of branching lower extremity arteries.
CFA bifurcates into the profunda and superficial femoral artery, superficial FA becomes the popliteal artery and then becomes the tibial-peroneal trunk and bifurcates into the posterior tibial and peroneal arteries
the ATA arises from the popliteal artery; dorsalis pedis branches off the ATA.
What does a normal doppler waveform look like?
bidirectional and bi to triphasic
flow reversal relates to greater resistance of flow
PAOD reduces flow energy distal to the lesion; what does this look like?
reduction of peripheral resistance, reduced amount of fow reversal
In critical stages of PAOD, what happens?
arteriolar bed can no longer dilate to increase blood flow and the patient experiences rest pain
If there is disease, what will happen to the pressures in the leg?
there will be a significant pressure drop
What is a TBI?
when toe pressure is compared to the brachial pressure
What is an ABI?
ankle pressure compared to brachial pressure
percentage of pressure you have compared to right atrium of heart
ex: if heart pressure is 100 and thigh is 60l it has 60% of prssure (ABI=0.6)
If waveforms and pressures appear unhealthy to begin with, what is the conclusion?
stenosis is proximal to the CFA
Before beginning a segmental systolic pressure exam, what should be done?
let patient rest for 10-15 minutes (which ensures true resting levels of blood flow)
How do you find the right BP cuff fit?
the width should be 20% wider than the diameter of the underlying limb
What happens if the BP cuff is too narrow or too wide?
if too narrow, falsely elevated pressure
if too wide, falsely lower pressure
What are the two ways segmental systolic pressures can be taken?
three cuff method and four cuff method
What is the three cuff method?
one large cuff on thigh, one below the knee, one at the ankle
What is the four cuff method?
two smaller cuffs on thigh(hihg and above knee), one at calf, and one at ankle
Is one cuff method better than the other?
four cuff method allows ability to further define level of disease by seperating iliofemoral disease from superficial femoral artery disease
At what levels are pressures obtained from?
pressure are obtained from the ankle level followed by the calf then thigh levels
What is used for pressure measurement up the limb?
the PTA or DPA (which ever is highest)
Doppler signal is obtained ___ to cuff.
distal
The cuff should be inflated ____mmHg above point where signal disappears.
20 mmHg
What is the rate of deflation of the cuff?
3 mmHg/s
What indicates the overall severity of PAOD?
ABI
How is ABI calculated?
calculated by dividing highest systolic ankle pressure by the higher of the two brachial systolic pressures
With an ABI of greater than 1.3, what is the level of severity of PAOD?
incompressible
What is a normal ABI?
0.9 - 1.3
about 1
What indicated mild PAOD?
ABI of 0.75-0.89
What indicates moderate PAOD?
0.5-0.75
What indicates severe PAOD?
less than 0.5
What indicates tissue threatening severity of PAOD?
less than 0.35
What is considered a significant change in ABI between studies?
change of 0.15
What do excessively high ABI values typically correspond to?
calcified arteries
interpretation then relies on waveform analysis
What disease may you see calcified vessels in?
diabetes
What does ABI indicate?
overall severity of disease, but not necessarily the site
What happens to systolic pressures as you travel distally down the leg?
pressures increase
Pressure drops of ___ indicate presence of proximal obstruction.
greater than 30 mmHg
Width of thigh cuff changes interpretation. What does a single large cuff do? a narrow cuff?
single large cuff results in a thigh pressure equal to the brachial pressure
us of a narrower high thigh cuff results in higher thigh pressure(about 30mmHg above brachial)
What should doppler waveforms proximal to the knee look like?
triphasic/biphasic and bidirectional
Why is exercise testing done?
primarily used in patients with intermittent claudication with normal ABIs at rest
What are typical treadmill settings for exercise testing?
10% grade, 1-2 mph, maximum walking time of 5minutes
What are contraindications for treadmill testing?
chest pain, arrhythmias, post-myocardial infarction/cardiac procedure, unsteadiness, and hypertension (>180mmHg)
What pressures are assessed immediate following the exercise?
ankle and brachial pressures
pressures are repeated every 1-2 minutes until they return to baseline
What indicates single or multiple PAOD?
recovery time
What is a single level disease?
ABI that returns to preexercise level within 5 minutes
one diseased area
What is a multilevel disease?
ABI that returns to preexercise level more than 10 minutes
tandum lesions
What are other names for air plethysmography? What is this used for?
pulse volume recording (PVR) and volume pulse recording (VPR)
can be used in patients with calcified vessels
How far do you inflate each cuff for air plethysmography?
55-65 mmHg
What happens with an air plethysmography?
venous flow is obstructed (you do not want to obstruct arterial flow), changes occuring under cuff are from arterial inflow, volume in limb changes with the cardiac cycle, pressure change is converted to a waveform
What shoud a normal PVR include?
rapid upstroke with well defined peak, notch on downstroke in early diastole (dicrotic notch), return to baseline through remainder of diastole
What would a PVR look like with moderate to severe disease?
delayed onset to peak, round peak, diastolic phase becomes convex
How are waveforms obtained in the digits?
with PVR or photoplethysmography (PPG)
What is a normal waveform of the toe?
brisk systolic upstroke, well-defined peak, concave shape on return to baseline during diastole
What is a normal TBI?
greater than or equal to 0.8
When is TBI useful?
when ankle vessels are incompressible
Toe pressure of ___ mmHg indicates adequate pressure for healing
50 mmHg
What does a triphasic waveform represent?
healthy elastic arterial wall
What does a waveform look like at a stenosis?
the upstroke is striaght up or starting to slant; peaks are rounded/extended; low resistance; higher peak systole, higher end diastole
What does a waveform look like directly after stenosis?
lots of turbulence
What does a waveform look like down stream from a stenosis?
hilled appearance (tardus parvus); low resistance, delayed rise to peak systole
What is the gold standard for testing chronic arterial insufficiency?
indirect testing
What are signs and symptoms of chronic arterial insufficiency?
intermittent claudication, rest pain, non-healing ulcers, gangrene, trophic changes(hair loss, nail thickening, skin changes) of leg
Is chronic arterial insufficiency an emergency?
no; it slowly progresses
What is the main cause of chronic arterial insufficiency?
atherosclerosis
What are signs and symptoms of acute arterial insufficiency?
pallor(unhealthy pale), pulselessness, paralysis, paresthesia(burning/prickling sensation), intense pain, coolness; palpable mass(suggestive of aneurysm)
What can cause acute arterial insufficiency?
clot (embolism) or trauma
if an embolism is seen, probable aneurysm elsewhere
What is a patient with acute arterial insufficiency at risk for?
limb loss
What are risk factors for arterial insufficiency?
diabetes, hyperlipidemia, hypertension, smoking, coronary artery disease, end-stage renal disease, obesity, sedentary lifestyle, heredity, gender, age
How should the patient be positioned for a direct test?
supine with knee slightly flexed and thigh abduction;
LLD may be used to evaluate popliteal artery, tibioperoneal trunk, and peroneal artery
What are pitfalls of direct arterial testing?
calcified vessels, extremely low flow, uncooperative patients, swelling/depth of vessels may limit visualization, exm length in complicated cases
Where can aneruysmal disease be found?
bilateral and multilevel
When is it considered an aneuysm in a vessel?
when diameter of vessel is 1.5 times greater than the adjacent more proximal segment
What do abnormal color findings include within a vessel?
aliasing, reduced flow channel, color bruit
As you go distal down the artery, what happens to the velocity?
velocity decreases
if turbulence/aliasing is seen, it shows an increase in velocity and indicates a probable stenosis
Where is the ATA found?
via lateral approach on interosseus membrane
What is a color bruit?
vibration in tissues
slow down and pay attention, may indicate stenosis
What should a normal spectral waveform look like?
sharp upstroke, rapid deceleration, reflected wave with retrograde flow in early diastole, brief wave of antegrade flow in mid to late diastole
Abnormal spectral findings include:
PSV velocity ration of 2 or more is 50% or greater stenosis
PSV velocity ratio of 3 or more is 70% or greater stenosis
Decreased distal restisistance appears as…
antegrade flow through diastole, sharp systolic upstroke
What may decreased distal resistance be caused by?
arteriovenous fistula (something damages wall of artery and vein and arterial flow goes right into the vein), trauma, cellulitis, post-exercise
A diacrotic notch is more associated with what type of wave?
PVR
Proximal to an occlusion, what will the spectral waveform look like?
very high resistance, antegrade flow component only during systole, no diastolic flow
(the heart pumps blood and it hits a wall)
What is the gold standard for diagnosing of arterial stenosis?
contrast arteriography
Contrast angiography can be used when duplex imaging is limited, such as:
severe arterial calcifications, severe edema or morbid obesity, extremely limited run-off (calf circulation), extensive skin wounds, extremely low flow
What are limitations of contrast arteriography?
delineates patent arterial lumen only, misses thrombosed popliteal aneurysms, fails to visualize outflow and inflow in very low-flow situations, requires potentially nephrotoxic agents, requires use of ionizing radiation, delays prompt treatment
What does tardus parvus mean?
slow/low late flow
List the four phases of an erection:
- cavernosal arterioles are constricted in resting phase
- upon stimulation of erection, cavernosal arterioles relax
- cavernosal sinusoids fill and become engorged
- enlarging sinusoids restrict venous flow
What is the function of the corpus cavernosa?
filling/draining of blood
What is effected with erectile disfunction?
corpus cavernosa
What occurs during phase one of an erection?
cavernosal arterioles are constricted in resting phase: little to no flow
What occurs during phase two of an erection?
upon stimulation of erection, cavernosal arterioles relax: low resistive flow
What occurs during phase three of an erection?
cavernosal sinudoids fill and become engorged
slow drop off of end diastolic flow
resistance is setting in
What occurs during phase four of an erection?
enlarging sinusoids restrict venous outflow
high restistive state
What are the main causes of erectile dysfunction?
main causes are vascular
What is the statistic for erectile disfunction?
52% of men between ages 40-70 years experience this
What are causes of ED?
physical (arterial, structural, venous), phychological, pharmacological (due to medicine with side effects)
What is the leading cause of impotence?
vascular pathology
What is the sonographic technique for a penile US?
penis extended up against abdomen, use of dorsal approach at base of penis; angle of insonation less than 20 degrees
What is the normal peak systolic velocity at a flaccid state?
greater than 10 cm/sec
What is the normal post-intracavernous injection systolic velocity?
greater than 25 cm/sec
What is seen sonographically with arterial insufficiency?
low velocity, low resistance
What is seen sonographically with venous incompetence/venous leakage?
sharp upstroke, PSV of greater than 25 cm/sec
elevated end diastolic velocity
What is Peyronie’s Disease?
benign localized connective tissue disorder (fibrous thickening of the tunic albuginea)
it is ideopathic
prevalence around 3%
Sonographically, what does Peyronie’s Disease?
irregular thickening of the tunica albuginea with or without plaque, associated with arterial insufficiency and venous leakage, also may have calcifications
What is priaprism?
a persistent penile erection that continues hours beyond, or is unrelated to sexual stimulation
What is low priaprism?
results from siinusoidal thrombosis and veno-occlusion
What are symptoms of low priaprism?
painful, rigid erection(urgent)
Sonographically, what does priaprism look like?
high resistive and low velocity in cavernosal artery; non-compressible, enlarged hypoechoic sinusoids
can lead to ischemia
What is high flow priaprism?
usually delayed sequela to genital trauma, due to creation of arteriocavernous fistulas
What are symptoms of high flow priaprism?
painless, non-rigid erections (non-urgent)
Sonographically, what does high flow priaprism look like?
fistula (turbulent arterial flow, connecting to nearby vessel); anechoic to hypoechoic compressible cavernosa
What is the quickest way to see if there is a lower extremity vascular problem?
calculate ABI
How do you compare segmental pressures?
by the origin/source
so compare it to the more proximal segment
>30mmHg pressure drop is abnormal
How do you evaluate inflow?
comparing thigh pressures to brachial pressures
thigh pressure should not be lower than brachial pressure
How do you evaluate femoral flow?
comparing low thigh pressure to high thigh pressure
and also to the contralateral
How do you evaluate popliteal flow?
comparing high calf pressure to low thigh pressure and also to the contralateral
How do you evaluate runoff?
comparing ankle pressure to high calf pressure and also to the contralateral
What ABI levels indicate single level disease? multilevel?
ABI > 0.5 the disease is single level
ABI <0.5 the disease is multilevel
The lowest value of post activity ABI categorizes what?
functional severity of limb
What are the steps for ABI?
- calculate ABI
- evaluate inflow
- evaluate femoral flow
- evaluate popliteal flow
- evaluate run-off
- evaluate single-level vs. multi-level disese
- evaluate post exercise ABIs
