CDI
Color Duplex Imaging
True or False: CDI can be used to identify the exact anatomical location of arterial occlusive disease
true
high pressure extravasation of blood out of an artery and into the surrounding tissue
pseudoaneurysm
What segments of the lower extremities should be imaged before attempting to scan the aorto-iliac segment?
femoral-popliteal segments
for lower extremities, select a transducer based on patient ________. A _________ transducer. Or in thin patients, a ______ may work.
body habitus; 2.5-3.5 curved array or phased array; low-frequency flat linear array
There are three scanning "zones" along the length of the iliac arteries. The first zone is usually seen on most patients. Which zone is the most difficult to interrogate?
the second zone (with the distial CIA, the IIA and the EIA)
The normal spectral waveform in the distal aorta and iliacs is ________ and similar to that found in the _________.
triphasic; femoral artery
What is the most reliable indicator for the presence of a 50% or greater stenosis aortoiliac segment?
2:1 systolic velocity ratio with focal velocity acceleration (twice as fast flow) and post stenotic turbulence
What are the most common segments for arterial occlusive disease in the lower extremities?
common femoral; superficial femoral; popliteal
when identifying the common femoral artery and common femoral vein in transverse at the inguinal ligament, where does the vein lie?
medial to the artery
the demarkation point where the EIA ends and the CFA begins is the ________. Can you see it in the ultrasound image?
inguinal ligament; nope
what type of waveform in the femoral popliteal segment would indicate iliac disease?
low amplitude, delayed rise time (>144 msec), or turbulence
CFA waveform with tardus parvus could indicate
distal aortic stenosis; iliac disease
what would this process help you do:
if there is no detectable flow in the segment, identify collateral runoff proximally, follow the segment distally using the vein as a guide, and identify the region of inflow/reconstitution.
estimate the length of an occlusion (find the beginning and end)
the ________ at the adductor canal is difficult to evaluate and frequently the site of atherosclerotic disease.
distal SFA
What acceleration time (AT) in the distal external iliac artery (or CFA) suggests significant iliac disease (greater than 75% diameter reduction)
greater than 144 msec
velocity acceleration over a stenotic lesion that achieves a 2:1 systolic ratio and is followed by post-stenotic turbulence indicates what?
This is in the lower extremity chapter
50% or greater stenosis
what is the velocity ratio?
velocity proximal to the stenosis divided by the maximum stenotic velocity
criteria for SFA-Popliteal stenosis:
Normal
PSV <150 cm/s; Velocity Ratio 1.5:1
criteria for SFA-Popliteal stenosis:
30-49%
PSV 150-200 cm/s; Velocity Ratio 1.5:1-2:1
criteria for SFA-Popliteal stenosis:
50-75%
PSV 200-400 cm/s; Velocity Ratio 2:1-4:1
criteria for SFA-Popliteal stenosis:
>75%
PSV >400 cm/s; Velocity Ratio >4:1
True or False: It is uncommon to find retrograde flow in the profunda femoris artery to supply the SFA in the event of a CFA occlusion.
false: common.
True or False: it is common to find reversed flow in the internal iliac artery to feed the external iliac artery
true
which lower extremity arteries are difficult and time consuming to study in patients with atherosclerotic occlusive disease?
posterior tibial; peroneal; anterior tibial
first branch of the popliteal artery
anterior tibial artery
the popliteal bifurcates into the
first the anterior tibial and tib-pero trunk; the tibial-peroneal trunk bifurcates into the peroneal and posterior tibial artery
flow direction INTO the tibial artery most likely represents
reconstitution distal to occlusion
use _____ as landmarks. From chapter on lower extremeties
paired veins
begin the scan of the posterior tibial artery just posterior to the ______ and follow the artery proximally along the course of the ______.
medial malleolus; tibia
occluded segments of the tibial artery should be noted and confirmed by what?
presence of collateral outflow and inflow
what divides the ATA from the DPA?
ankle crease
In a transverse view, the ATA will lie just above the ________ that courses _________. The peroneal artery is ________.
interosseous membrane; between the tibia and fibula; deeper than the membrane
popliteal artery aneurysms:
If thrombosed, what is the amputation rate?
How often bilateral?
Likelihood of AAA in these patients?
40-75% amputation; 50-70% bilateral; 43% AAA
symptoms of popliteal artery aneurysms:
claudication; rest pain; limb ischemia; blue toe; nerve compression/pain
true or false: a pseudoaneurysm has no arterial wall encapsulating the aneurysm
true
what flow pattern usually exists in the pseudoaneurysm neck?
a "to and fro" flow pattern
Causes of pseudoaneurysm
percutaneous arterial catheterization; penetrating trauma; graft anastomosis "blowout
Why does blood flow back in the artery during diastole (in a pseudoaneurysm)?
the pressure in the pseudoaneurysm is higher than in the artery during diastole, so it flows to where the pressure is lower
arterialized venous flow can be seen when?
arterio-venous fistula
P-an
pseudoaneurysm
CABG
coronary artery bypass graft
what veins are used as arterial conduit for CABGs?
Or to revascularize leg with a femoro-popliteal or femoro-tibial bypass graft?
What arteries:
saphenous veins; superficial cephalic veins; basilic veins;
radial or ulnar artery
When scanning the arms, note the position of the ___________. It is important to know if it is in the ______ or if it bifurcates higher in the arm.
brachial artery bifurcation into the radial and ulnar arteries; antecubital fossa
what provides collateral pathway so that the entire hand and all digits can be perfused by either the ulnar or radial artery?
the palmar arches
goal of palmar arch test (Allen test)?
confirm patency of the arch
The test for palmar arch patency can be performed with
an Allen test
The Allen test for Palmar arch patency is performed with what physiologic testing devices?
Photoplethhysmography (PPG) sensors placed on thdumb or index finger and the 5th digit
3 Above Inguinal Ligament Grafts
1. Aorto-bifemoral graft;
2. Femoral to femoral "jump" graft;
3. Axillo-femoral, fem-fem bypass
which above inguinal ligament graft is used to bypass a diseased distal aorta and/or iliac arteries?
aorto-bifemoral graft
what scars will a patient have with an aorto-bifemoral graft?
a scar near the umbilicus and one in each groin region
what graft is used to bypass a single iliac artery?
a femoral to femoral "jump" graft
what is the intended flow direction with a femoral to femoral "jump" graft?
should be from asymptomatic leg to preoperative symptomatic leg
what scars are expected with a femoral to femoral "jump" graft?
scar at each groin
which graft is used to bypass the abdominal aorta?
axillo-femoral, fem-fem bypass
what is the proximal anastomosis for the axillo-femoral, fem-fem bypass?
axillary artery
autogenous
made by or from one's own tissues
with the in situ fem-pop or (fem-tibial) vein graft the procedure uses the ________ for arterial conduct. The valves are _______.
great saphenous vein (GSV); excised
in what procedure is the GSV removed, turned upside down and sewn back in? The valves are not removed or excised as in the in situ method.
reversed vein graft
a significant number of bypass grafts are performed for
limb salvage
if a graft occludes, a thrombectomy is usually performed to restore patency. However, there is a ______% re-occlusion rate.
50-80%
Scan Method for Bypass Grafts:
Obtain ABIs and ankle PVRs or Doppler Waveforms and compare to _________; A drop of ________ in the ABI from the previous exam suggests progressive graft stenosis.
previous exams; 0.15
Scan Method for Bypass Grafts:
Use image, color, and spectral Doppler to evaluate:
1. Graft ______.
2. The entire graft lumen for: stenosis, wall irregularity, aneurysums, pseudoaneurysms (graft blow out), A-V fistulas from non-ligated perforators, and __
inflow; valve leaflets; stenosis; defects; neo-intimal hyperplasia; seroma; profunda femoris
the most common cause for restenosis with an arterial bypass graft using a vein?
neo-intimal hyperplasia
***Your patient undergoes carotid endarterectomy. Six months later angiography is performed because of symptoms referable to the other side. The angiogram reveals that the operated carotid is significantly narrowed. The most likely cause is:
Neo-intimal hyperplasia (rapid proliferation of intimal cells causing wall thickening and lumen encroachment)
vein grafts often develop ______ due to the shear stress of arterial flow on a thin vein wall.
neo-intimal hyperplasia
blood flow in the aortic arch flows
clockwise
Arm Arteries
axillay; brachial; interosseous; radial; ulnar
indications for upper extremity arterial evaluation:
arterial insufficiency; weakness in the arm; thoracic outlet syndrome; vasospastic disorder (digital cold sensitivity); digit ischemia; abnormal vertebral artery waveform; preoperative assessment (hemodialysis access or radial artery harvest for coronary
preoperative assessments for arterial upper extremities include
hemmodialysis access and radial artery harvest for CABG
contraindications for arterial evaluation of the upper extremeties
no arm pressure measurements on an arm with a hemodialysis access
you can't take arm pressure measurements on an arm with a hemodialysis access. What is okay?
PVRs, with reduced inflation pessure, or Doppler waveforms
weakness in the arm is a sign of
obstruction on that side
Disease processes that may indicate the need for an arterial upper extremity exam include:
large vessel occlusive disease; thoracic outlet syndrome; small vessel occlusive disease (fixed); small vessel occlusive disease (vasospastic disorder); Raynaud's phenomenon
Of the upper extremities, atherosclerotic obstruction occurs predominantly where?
subclavian and innominate
true or false: the axillary, brachial, radial, and ulnar arteries are likely to be involved with large vessel occlusive disease
false - less likely (subclavian and innominate are likely)
autoimmune disorders that affect the aortic arch and proximal vessels in young to middle-aged females of Asian descent.
Takayasu's and giant cell arteritis (Large Vessel Occlusive Disease)
what upper extremity arteries may be involved in Takayasu's and giant cell arteritis (Large Vessel occlusive disease)
brachiocephalic, subclavian, and left common carotid
what bilateral brachial systolic pressure gradient suggests subclavian artery disease (or possibly innominate if on the right) on the side with the lower pressure?
greater than or equal to 20 mmHg
subclavian stenosis/occlusion is diagnosed by comparing
bilateral brachial systolic pressures. A greater than or equal to 20 mmHg gradient suggests stenosis/occlusion on the side with the lower pressure.
Right Brachial Pressure: 145 mmHg
Left Brachial Pressure: 115 mmHg
What would this indicate?
subclavian stenosis or occlusion (30 mmHg difference)
acute obstruction of the distal arteries caused by emboli from subclavian artery disease, proximal aneurysm, or the heart;
What does the site of obstruction depend on?
thromboembolism; the size of the embolus relative to the size of the artery
intermittent pain, numbness, or weakness of the arm(s) related to arm position may indicate:
thoracic outlet syndrome (TOS)
TOS is caused by compression of the _____ or ______ by the _________ muscle, clavicle, rib, or congenital muscular anomalies.
artery; nerve; anterior scalene muscle
TOS is common in ______.
body builders
what percent of TOS is neurogenic (rather than due to compression of the artery)
95%
what percent of symptomatic TOS is caused by compression of the subclavian or axillary arteries?
less than 5%
TOS may cause
thrombosis, fibrosis, and aneurysm of the subclavian or axillary arteries.
small vessel occlusive disease - fixed - includes:
Buerger's disease (thromboangiitis obliterans) and Thromboemboli
another name for Buerger's disease
thromboangiitis obliterans
inflammatory condition of the palmar arch and/or digital arteries.
Buerger's disease (thromboangiitis obliterans)
Buerger's disease is found most often in whom?
male smokers
small emboli that occlude the arteries of the hands and digits
thromboemboli
small vessel occlusive disease (vasospastic)
Raynaud's Phenomenon
Raeynaud's Phenomenon is episodic, prolonged, _________ brought about by cold exposure, ________, emotion, or occupational trauma. The toes can also be affected.
digital vasospasm; chemicals (nicotine)
Which form of Raynaud's disease has no underlying cause. The digital and palmar arteries are without obstruction, and perfusion to the digits at rest is normal
Primary (Raynaud's Disease)
Which form of Raynaud's disease is associated with an underlying autoimmune disease or connective tissue disease. The digital/palmar arteries often have fixed obstruction
Secondary Raynaud's (Syndrome)
In secondary Raynaud's (syndrome) even a normal vasoconstrictive response to cold can cause
severe transient ischemia
which autoimmune conditions are associated with secondary Reynaud's (syndrome)?
lupus, scleroderma, rheumatoid arthritis
Symptoms of Raynaud's include _______ of digits during vasospasm, followed by ________ and _______ upon release of the spasm.
pallor; cyanosis; rubor
How long might the spasm take to release in Reynaud's?
10-30 minutes
what percent of Raynaud's phenomenon cases occur in females?
70-90%
what percent of Raynaud's cases are related to connective tissue disorders (scleroderma, lupus, rheumatoid arthritis)?
40%
What percent of Raynaud's are idiopathic?
40%
What percent of Reynaud's cases are caused by other etiology such as frostbite or repetitive vibration
20%
Treatment for Reynaud's includes:
sympathetic blocking agents; treat associated disease; cervico-thoracic sympathectomy;
What else?
stop smoking; avoid cold/stress; calcium channel blockers (Procardia, Nicardipine); micro-revascularization; relocation to warm climate
PVR
pulse volume recording
After the baseline study (segmental pressures and PVRs or PPGs), obtain a waveform with one of the following methods to serve as a baseline reference for positional THORACIC OUTLET TEST (TOS)
PPG on index fingers; PVRs of arms; CW-Doppler tracings from radial or ulnar arteries
After obtaining a waveform to serve as a baseline reference for positional TOS study, obtain tracings from both arms in following arm positions:
abducted 90 degrees to torso; elevated 180 degrees above head; pledge position (first with head turned toward, and then away, from the hand); "Stick-Up" position; symptomatic position
what exam is essential prior to radial artery harvest for coronary artery bypass surgery and prior to ipsilateral hemodialysis fistula or graft implantation
Allen test for Palmer Arch Patency
If the radial artery is removed in a patient that is radial dominant and if the palmar arch is not intact, what may result?
severe ischemia in the fingers and hand
what should be performed on all fingers prior to the Allen test?
a standard resting digit exam
Allen test may be performed ________ or with monitoring devices (______, _______, or _______) on the thumb and index finger.
manually without instrumentation; PPG: PVR: digit pressures
absence of capillary refilling during an Allen test suggests what?
an occluded palmar arch or radial/ulnar dominance
Signs and symptoms of chronic occlusive disease
Claudication, ischemic rest pain, tissue loss (necrosis)
signs and symptoms of acute arterial occlusion
The 5 Ps: pallor, pain, pulselessness, paresthesia, paralysis, polar, purplish
Pain in muscles occurring during exercise but subsiding with rest
claudication
True claudication results from inadequate blood supply to the exercising muscle, which may be caused by any of or a combination what 4 things?
arterial spasm; atherosclerosis; arteriosclerosis; occlusion
various types of claudication include
buttock (aortoiliac disease); thigh (distal external iliac/common femoral disease); calf (femoral/popliteal)
buttock claudication strongly suggests ________. If the symptoms are unilateral, this suggests ________
aortoiliac disease; iliofemoral disease
thigh claudication suggests ___ disease
distal external iliac/ common femoral
calf claudication suggests ___ disease
femoral/popliteal disease
what is a more severe symptom (than claudication) of diminished blood flow to the most distal portion of the extremity?
ischemic rest pain
With Ischemic Rest Pain the patient will have pain at rest(sleeping), symptoms occur in the _____________, _________, and _________, but
NOT IN THE CALF
forefoot, heel, toes
what is the most severe symptom or arterial insufficiency?
tissue loss (necrosis)
acute arterial occlusion may result from
thrombus, embolism, or trauma
acute arterial occlusion is an ___________. Why?
emergency; abrupt onset does not provide for development of collateral channels
cold sensitivity symptoms include
changes in skin color (pallor, cyanosis, rubor), paresthesia, and pain
intermittent ischemia of the fingers or toes in response to cold exposure as well as emotional stress
Reynaud's phenomenon
Risk factors and contributing diseases for Chronic occlusive disease and acute arterial occlusion
diabetes mellitus; hypertension; hyperlipidemia; smoking; age, family history; male gender
atherosclerosis is more common among ______ and occurs _______.
diabetics; at a younger age
chemicals in cigarettes irritate the endothelial lining of the arteries in addition to causing
vasoconstriction
what is the most common arterial pathology?
atherosclerosis
another term for atherosclrosis
arteriosclerosis obliterans
atherosclerosis (thickening, hardening, and loss of elasticity of the walls) occurs most often where?
carotid bifurcation; origins of brachiocephalic; origins of visceral vessels (SMA/Celiac); SFA; Popliteal trifurcation
true aneurysm
dilation (bulging) of all three layers of the arterial wall
pseudoaneurysm
pulsing hematoma
arteritis
inflammation of the arterial wall - often results in thrombosis
several types of arteritis
Takayasu's, temporal, polyarteritis, Buerger's disease
the most common form of arteritis
Buerger's disease
Buerger's disease is associated with:
heavy smoking; men younger than 40; occlusions of distal arteries; rest pain and ischemic ulceration; superficial thrombophlebitis
Primary Raynaud's is also called _______; and _________. It involves intermittent digital ischemia caused by digital arterial spasm. Common in _________; may be hereditary; usually _________. No evidence of cause; rather benign with excellent prognosis
spastic Raynaud's; Raynaud's disease; young women; bilateral;
secondary Reynaud's is also known as _______. It consists of normal vasoconstrictive responses of the arterioles superimposed on a ________. Ischemia is constantly present. Associated with underlying autoimmune condition.
obstructive Reynaud's syndrome; fixed arterial obstruction;
secondary Raynaud's may be the first manifestation of what?
collagen disorder; Buerger's disease; or anatomic abnormality
The most written about entrapment syndrome?
entrapment of the popliteal artery
entrapment of the popliteal artery is commonly found in ______, and is bilateral in about ______ of cases.
young men; one third
pallor is a result of _____. Skin color is pale
deficient blood supply.
Rubor (reddish discoloration) suggests
damaged, dilated vessels
cyanosis (bluish discoloration) occurs due to
lack of O2 in the blood
Purple patches (similar to bruising) on the skin of the dorsum of the foot. Usually the result of dilated capillaries and venule filling, not arterial obstruction.
Livedo reticularis
death of tissue caused by deficient or absent blood supply
gangrene
grading pulses on a scale of 0-4 is fairly standard. Always compare the pulse palpated on one side to the pulse at the same site on the other. How does the grading go?
0 = none; 1+ = weak; 2+ = good; 3+ = strong; 4+ = bounding
For the lower extremities, Doppler velocity waveforms are recorded from the following arteries bilaterally:
CFA; DFA; SFA; POP; PTA; ATA; Peron; DPA
normal upper and lower extremity arterial waveforms are
triphasic or multiphasic with rapid upstroke
abnormal upper and lower extremity arterial waveforms are
monophasic, nonpulsatile, or absent
segmental pressures are used to look for
PAD
true or false:
Doppler segmental pressures of the lower extremities can discriminate between stenosis and occlusion and precisely locate the area of obstruction
false - cannot; can identify only a general location
true or false: ABI is calculated by dividing the ankle pressure by the lower of the two brachial pressures
false - higher
normal ABI
>1.0
severe arterial disease ABI (rest pain)
<0.5
asymptomatic minimal obstructive disease ABI result
>0.9-1.0
moderate disease ABI (claudication)
0.5-0.8
Mild arterial disease ABI
0.8-0.9
moderate arterial disease causes
claudication
severe arterial disease causes
rest pain
with ABI, a decrease in pressure of _________ between two consecutive levels is considered significant and would suggest significant obstruction. Other sources indicate a decrease in pressure of _______ suggests significant obstruction
>30 mmHg; greater than or equal to 20 mmHg
incompressible vessels are _________ and therefore inaccurate. What ABI is considered to be the result of incompressible vessels?
falsely elevated; >1.3-1.5 or higher
pressures that are not reproducible are also considered to be
incompressible
Normally, the ankle systolic pressure is _________ than the higher brachial pressure.
the same as or greater than
Dopppler segmental pressure study is usually combined with what?
Doppler velocity waveforms or plethysmographic waveforms (volume pulse)
which are more important with the ABI? Horizontal or vertical pressure differences?
vertical
as limb girth increases from the ankle to the thigh, what happens with pressure measurements?
they also increase
technique for Duplex scanning of upper extremities
patient supine; extremity close to examiner; arm externally rotated and postitioned at 45 degree angle in pledge position
re: upper extremity Duplex scanning:
for a patient with a dialysis graft, be sure to do what? Keeping in mind that both a graft stenosis and the high volume of blood flow through a dialysis graft will produce this.
ausculate for bruit/palpate for a thrill
what frequency transducer is used for upper extremity imaging?
multifrequency (5-7MHz) linear array
Upper extremity Duplex scanning is performed at the following anatomic sites in this order:
subclavian a; axillary a; brachial a; radial a; ulnar a; palmar arch if necessary
spectral Doppler of the brachial artery should be
triphasic; high resistance
is it common or uncommon for arteries in the upper extremities to become stenotic?
uncommon
main use for duplex and color flow imaging in the upper extremities (since it's rare for these arteries to become stenotic) is?
evaluation of hemodialysis access grafts, vein mapping, evaluation for thrombosis
hemodialysis grafts are evaluated in the following order:
eval inflow artery; eval arterial anastomosis; eval body of the graft; look for abnormalities (aneurysm, puncture site leaks, perigraft fluid); use color to look for frequency increases, turbulence, and flow channel changes; eval venous anastomoses; eval
types of dialysis access include
Brescia-Cimino fistulas (i.e. radial artery and cephalic vein); straight synthetic grafts (i.e. brachial artery to axillary vein); looped synthetic grafts
popliteal artery entrapment syndrome is thought to be caused by
compression of the popliteal artery by the medial head of the gastrocnemius muscle or fibrous bands
abnormal plethysmographic (PPG) waveforms noted in both dorsiflexion and plantar flexion on one side with normal PPG waveforms on the other side with the same activity suggest
popliteal entrapment
popliteal artery entrapment syndrome is most commonly found in ________. How often bilateral? Repeated trauma to the pop a. may result in what?
young male athletes; one-third bilateral; development of aneurysm, thrombosis, atherosclerosis, and emboli
how do patients with popliteal entrapment syndrome present?
symptomatic arterial occlusion or intermittent claudication
with popliteal entrapment syndrome, what happens to pulses and waveforms when the knee is extended and with active plantar flexion or passive dorsiflexion?
pulses may diminish and waveforms (Doppler, PPG) may be altered
A young male complains of pain in the calf muscle following exercise. Vascular lab findings reveal normal pressures, pulses, and plethysmographic waveforms at rest, but abnormal decreases during active plantar flexion or passive dorsiflexion of the foot.
popliteal artery entrapment syndrome
thoracic outlet syndrome (TOS) occurs when?
neurovascular compression by the shoulder structures (cervical rib, costoclavicular ligament, scalene muscle)
symptoms of TOS
numbness or tingling of the arm and pain in or aching of the shoulder and upper arm; hand may have symptoms of pain, numbness/tingling, and weakening grip.
what exascerbates symptoms of TOS?
exercise and upward arm positions
what percent of the population have asymptomatic compression (brought up in the paragraph about TOS)
25-30%
Technique for determining TOS
PPG and/or Doppler waveform analyis to detect arterial changes in the radial artery (resting waveforms and then waveforms as patient's arm is placed in various positions)
During assessment for TOS, patient sits erect with legs danging from table. Arm positions include:
resting (hands in lap); 90 degrees; 180 degrees; exaggerated military stance; adson maneuver (head turning); causative position
with TOS... a normal finding would be _______ and abnormal would be _______.
the resting waveform obtained by PPG or CW Doppler is maintained throughout the various arm positions; if waveforms are reduced or flatlined by positional changes.
Hypogastric artery is another name for the:
internal iliac artery
geniculate artery
circles around the knee
gastrocnemius artery
part of the popliteal artery?
what artery continues on as the Dorsalis pedis on the dorsum of the foot?
anterior tibial
one layer of endothelial cells suppported by internal elastic lamina
intima
the endothelium of the intima provides the following functions:
permeability - barrier that allows nutrient exchange; antithrombogenic - prevents platelets and monocytes from adhering to wall; vasoreactivity - realeses endothelin and prostacyclin causing vasoconstriction and dilation
middle layer of the arterial wall is called ______. What does it consist of?
media; smooth muscle cells and collagen
outer layer of artery wall is called _____. What does it contain?
adventitia; connective tissue, collagen, and vasa vasorum
smallest vessels in circulatory tree
capillaries
what controls blood flow in the lower extremities?
cardiac output; intraluminal wall resistance; arterial wall compliance; vasoconstriction and dilation in the distal vascular beds
the the basal or resting state, arterioles are _______. There is arteriovenous _______ in muscle capillary beds as not much blood is flowing to skeletal muscles. In this situation flow is ______ from aorta to arterioles.
vasoconstricted; shunted; high resistance
during exercise, _______ occurs. Triggers to this include:
vasodilation; low oxygen, increased CO2, increased lactic acid
During heavy exercise cardiac output increases, there is dermal vasoconstriction, but overall the theme is _______. blood is shunted from viscera to skeletal muscles. What percent of capillaries open? So therefor the A-V shunts do what?
vasodilation; 100%; close
In normal individuals a substantial increase in blood volume in peripheral arteries occurs mduring and volumes increase significantly over resting states. Arterial Doppler waveforms will exhibit what?
low resistance
If flow volumes are obtained from a popliteal artery at rest and compared to flow volumes after 3 minutes of exercise. Would the following finding be normal or abnormal?
resting volume was 55 cc/min; following exercise 914 cc/min
20 FOLD INCREASE IN VOLUM
normal
what decreases dramatically during exercise _________. So how is the pressure maintained?
peripheral resistance; by the increase in volume
vasodilation in lower vascular beds occurs _____ with onset of exercise
quickly
in patients with arterial occlusive disease, adequate distal perfusion may exist when? What happens when this is not the case?
at rest; during exercise, vasodilation occurs but the expected increase in blood volume does not occur, and skeletal muscles cannot obtain the necessary oxygen
if peripheral resistance decreases (due to vasdodilation) and flow volume doesn't increase, then what?
distal pressure will drop and patients may experience pain, fatigue, or cramping in the calf, thigh, or buttock (claudication)
intermittent claudication
pain, fatigue, or cramping in the calf, thigh, or buttock with exercise
if severe proximal disease is present, the Doppler waveform may be
monophasic with delayed rise time
risk factors for atherosclerosis (Daigle)
genetic; hypertension; diabetes mellitus; obesity; LDL >160; tobacco
arterial symptoms of mild arterial disease (PAD)
asymptomatic; decreased pedal pulses or abdominal bruit; mild decrease in ankle pressure w/exercise; may be seen with ultrasound, but doesn't reduce flow
arterial symptoms of moderate (claudication) arterial disease (PAD)
asymptomatic at rest; significant decrease in ankle pressure w/exercise; intermittent claudication (the most common symptom)
transient ischemic event in the muscles
claudication
the most common symptom of peripheral arterial disease?
claudication
arterial symptoms of severe arterial disease (PAD)
night pain in feet or toes; persistent ischemic rest pain; non-healing wounds; ulceration; tissue necrosis; gangrene; surgical intervention to revascularize or amputation
another name for atherosclerosis
arteriosis obliterans
all of the following are considered ______.
atherosclerosis
thrombosis
thromboemboli
blue toe syndrome
small vessel fixed occlusive disease (Buerger's)
digit vasospastic disorder (Raynaud's)
pulsatile masses
arteritis
entrapment syndromes
arterial pathologies
thromboemboli often originate from
aneurysms
blue toe syndrome is caused by
thromboemboli
the small vessel fixed occlusive disease called Buerger's disease is also known as
thromboangiitis obliterans
digit vasospastic disorder is
Raynaud's
pulsatile masses are
aneurysms and pseudoaneurysms
All of the following are examples of what?
popliteal artery entrapment; nutcracker syndrome; medial arcuate syndrome; SMA syndrome; thoracic outlet syndrome
entrapment syndromes
popliteal artery entrapment causes
claudication-like symptoms
Nutcracker syndrome occurs when the left renal vein is compressed by the _______.
SMA
median arcuate syndrome aka MALS
compression of the celiac axis
SMA syndrome
- compression of the 3rd part of the duodenum by the SMA
thoracic outlet syndrome
compression of the subclavian or axillary artery
in early atherosclerosis there is an endothelial ______ and deposition of _____ into the intima. This is followed by an __________ in which monocytes become macrophages that ingest lipids and lipoproteins and then become foam cells.
This is most likely to
injury; LDL; branch points and bifurcations; inflammatory response
As atherosclerosis progresses what happens?
migration/proliferation of smooth muscle cells from media wall off foam cells; fibromuscular cap formation over plaque
In late, advanced atheroclerosis necrosis occurs in the center of the plaque and macrophages may lyse. The hallmarks to remember are
rupture of fibrous cap; rupture of vasa vasorum
material within the necrotic core of advanced atherosclerosis is very thrombogenic. Which lesions are most likely to rupture?
those with a necrotic core and fibrous cap