Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
97 Cards in this Set
- Front
- Back
|
hydrostatic pressure
|
p=mgh
p=hydrostatic pressure m=density of the fluid g=force of gravity h=height of the column |
|
|
what are the limitations of bernoulii's equation?
|
-assumes that the points where flow is measured lie on a streamline
-assumes that flow has a constant density -assumes that there is no friction |
|
|
what does a non-newtonian fluid mean?
|
the viscosity of the blood changes the flow geometry, not just temperature
|
|
|
what 2 factors control perpheral vascular resistance?
|
-sympatheic nerve innervations
-autoregulation |
|
|
what is the formula for poiseuille's lae?
|
Q=(3.14)(changeP)(r4)/8Ln
|
|
|
what are the 2 periods of increased venous flow durind each cardiac cycle?
|
-at ventricular systole(v-wave)
-after AV valves open(after c-wave) |
|
|
what are the types of potential energy in he blood system?
|
-arterial wall elasticity
-intravascular pressure -hydrostatic pressure -gravitational potential energy |
|
|
flow; name 2 flow formulas
|
-measure of volume per unit time
-flow=velocity x cross-sectional area -flow=change in pressure/resistance |
|
|
explain how poiseulle's law, which addresses viscous energy losses, relates to flow in a stenotic segment?
|
-energy is lost from before a stenosis to after it
-energy loss is related to velocity in stenosis, length of the stenosis, and viscosity through stenosis -the tighter the stenosis, the more layers of blood have to be broken down(viscosity); so increased viscosity=increased resistance -small diameter changes=large rresistance changes |
|
|
what parameters increase the amount of energy lost to heat
|
-smaller cross sectional area
-rougher surface -increased velocity -higher viscosity |
|
|
pulse pressure
|
systolic pressure-diastolic pressure
|
|
|
when can a person's ablity to autoregulate go away?
|
when perforation pressure falls below a critical level(severe atherosclerosis)
-vessels remain fully dialated |
|
|
resistance formula
|
R= 8Ln/rto the 4th(3.14)
|
|
|
where is vasculitis often seen?
|
in the temeral artery in elderly
|
|
|
what do we need to do when determining if there is an ICA dissection?
|
-determine the extent of disection
-document hemodynamics -determine patency(eca & ICA) -is there collateralization -evaluate degree of stenosis |
|
|
what are bruit's related to/
|
post stenotic turbulence
a-v fistula transmitted cardiac murmur |
|
|
What is seen with ASO(atheroscloerosis obliterans)?
|
-endothelial injury followed by deposition of low-density lipoprotiens into the intima
-inflammatory response w/ smooth muscle cell proliferation in the media -arterial walls thicken, harden, and lose elasticity -plaque present |
|
|
explain the progression of vasculitis?
|
aneurysm
stenosis occlusion |
|
|
what are the ultrasound findings of vasculitis?
|
-long narrow segments due to thick walls
-tardus parous waveform |
|
|
what are the consequences of a disection, and possible ultrasound findings?
|
consequences:embolization, reduced flow, pseudoaneurysm
ULTRASOUND FINDINGS: -fluttering intima -flow disturbances -tapering ICA without plaque visible |
|
|
during relaxation, what venous valves open and close
|
proximal valves close due to hydrostatic pressure, and distal ad perforator valves open to allow blood to fill the empty venous segments
|
|
|
what is secondary venous incompotenceÉ
|
valve damage due to DVT
|
|
|
what are the risk factors for stroke that can be changed?
|
CHAD HIS C
-Cigarette smoking-causes constriction of arteries -High Blood pressure-most NB-increased wall stress causes atherosclerosis -A-fib-cause blood to pool and clot -Diabetes Mellitis-hardening of arterial walls -Hyperlipidemia-saturation of fat contributes to atheromatous plaque -Inactivity -Sickel cell anemeia-cells stick to walls -Carotid stenosis |
|
|
how does flow change btw systole and diastole?
|
there is plug flow in systole, and parabolic flow in diastole
|
|
|
what are the most influential factors for tubulence?
|
velocity ad the radius of the vessel
|
|
|
what is the formula for reynolds number? when reynalds number meets or exceeds what is there turbulence?
|
Re=Vq2r/n
|
|
|
where might there be an icrease in reverse flow component in late systole?
|
in high resitance systems(ie. lower extremity arterial flow)
|
|
|
what is primary venous insufficencyÉ
|
when ther eis congenital abscence of valvesor incomplete valve development.
|
|
|
what does autocorrelation provide?
|
-flow direction
0average or mean frequency shift -pwer or amlitude -varience |
|
|
FFT
|
-analysis of returing doppler signal and displays the frequency shifts on a spectral display.
-may velocities and frequecy shifts are represented -breaks down complex signals into each individual frequency groups and assigns them to bins. -vertical axis represents frequecy shift -horizontal axis resprests time |
|
|
what is autocorrelation?
|
-info from multiple pulses along one line is compared to preceding puse echo
-at least 3 pulses per scan line are required for autocorrelation -scan lines are processed to generate a frame of color doppler info based on frequency shifts occuring along each scan line |
|
|
analog dippler waveform generatioin
|
-zero-crossing detection-the number of times it crosser per time interval is the zero-crosing frequency
-does not display true peak frequencies |
|
|
explain the process of extracting the doppler signal?
|
-signal is weak compared to echos from tissue, so the signal is amplified and processed(domodulated)by the doppler system.
-sent to speakers -processes in an analog to digital converter, and stored in memory -digital signal sent for FFT analysis |
|
|
pulse sequence
|
-a pulse burst transmitted then the transmitting and recieving elements turn off.
|
|
|
what is teh cosine of 3, 40, and 50 degrees?
|
30-.87
40-.77 50-.64 |
|
|
what are the different types of atherosclerosis?
|
-coronary artery disease-A of the Coronary arteries
-cerebrovasclar disease-plaque in brain arteries(associated w/ CVA or stroke) -aortic atherosclosis-associated with aneurysms and plaque lining aortic wall -peripheral vascular disease-plaque in lower extremity arteries |
|
|
where does atherosclerosis first occur? what is it due to?
|
-first occurs at the interface vtw the blood and vessel wall(smooth endothelial linging)
due to: -metabolic problems -force of blood against wall |
|
|
explain the formation of atherosclerosis?
|
1. lipids accumilated in subendothelium
2. lipid material is ingested by macrohages, forming foam cells 3. smooth muscle cells migrate from muscular layer of endothelial layer: -becom transformed into fibroblasts -form a fibous matrix within plaque -form a fibrous cap |
|
|
how is mean frequency determined(Aka mean velocity)? what is this number used for?
|
deermined by taking the area underneath the spectral waveform
-used to calculated the pulsatility index |
|
|
distinguish btw the different types of quantifying bulb stenosis
|
washington/traditional/bulb method-stnosis compared to ECA regular diameter
-NACET, and ACAS-stenotic diameter comared to distal ICA diameter |
|
|
AI
|
acceleration index:
-relationship between systolic up slope to accleration time(rise/run) -cm/s2 -PS velocity/accel time |
|
|
What is the diameter reduction, peak sytolic velicity, and energy, and flow characteristics of an D, class stenosis?
|
-50-79% diameter reduction
->4khz; >125cm/s -marked spectral broadening is usually associated |
|
|
What is the normal pulsitility index of the abdominal AO, CFA, Pop A, and Post tib?
|
Abdominal AO-2-6
CFA-5-10 Pop A-6-12 Post Tib-7-15 |
|
|
Damping factor
|
measures the degree of attenuation of the doppler signal.
D.F=PI(from proximal sight)/PI (from distal site) |
|
|
mode frequency
|
highest amplitude and brghtest pixel
|
|
|
pulsitility index: definition and formula
|
-ratio of peak to peak height to mean height-varies from a normal vessel to a diseased one
|
|
|
what is pressure like distal to a stenosis?
|
reduced
|
|
|
what does ACAS stand for
|
assymptomatic
carotid atherosclerotic study |
|
|
What is the formula for acceleration time?
|
peak velocity/pulse rise time
|
|
|
what is the NACET criteria?
|
>50%-1ca/cca >2
>60%-PSV?260; EDV>70 >70%-ICA/CCA ratio-4; EDV>100 |
|
|
inverse damping factor
|
-ratio of distal pulstitility index to proximal pulsitility index
-measures the amount of damening of the flow wave as it progresses through an artrial segment I.D.F=Pi(from distal site)/PI(from proximal site) |
|
|
median frequency?
|
frequency below one half of th total power
|
|
|
what are some features of the vertebral artery?
|
-enter the foramina transversaria of the sixth cervical vertebrae
-leave at the atlanto-occipital interspace and loop anterior to enter foramen magnum -unite at pontomedullary junction to for basilar artery |
|
|
what are some causes of subclavian steal syndrome?
|
-atherosclerotic disese
-trauma -embolus -surgical complications -congenital cuses -neoplastic factors |
|
|
what branches of the ICA leave the intracrandial space?
|
-fronatal
-supraorbital -nasal artery |
|
|
Brain stem
|
-midbrain, pons, medulla oblongota
-relaycenter for eye and ear -connects nerve impulses from cerebellum |
|
|
what are some indications for vertebral artery assessment?
|
-flow direction
-vertigo -syncope -drop attacks -diplopia |
|
|
which eca collaterals can communicate with the opthalmic artery?
|
-occupital
-facial -superficial temporal -internal maxillary arteries |
|
|
what is the second most important source of collateral flow the the brain?
|
-anastomosis btw branches of teh ECA and ICA via the orbital and opthalmic arteries.
|
|
|
vertebral disections
|
-more common in young people
-spontaneous or related to injury-susceptible to injury at top of jeck -can result in stroke |
|
|
explain the waveforms of severe to mild subclavian steal syndrome
|
-complete subclavian steel-blood comes up and goes cross and down contralateral vertebral artery
-incomplete or partial steal-transient reversal of vertebral flow; may be converted into complete steal using provocative mesures -presteal or "bunny" waveform -tradus parvis waveform |
|
|
go over all of module 7 of vascular3
|
TCD testing stuff
|
|
|
peroneal artery
|
-adjacent to border of fibula
-terminates as external calcaneal artery -supplies lateral leg and foot |
|
|
venous TOS
|
-rare
-from thrombosis of subclavian or axillary vein secondary to compression -symptoms noticed w/ movement of the arm -lim may be edematous w/ distended superficial veins |
|
|
what are the causes for acute arterial occlusion?
|
-atherosclerosis
-embolic from proximal site -surgical procedures -arterial cannulation |
|
|
what are arterioal TOS symptoms?
|
-episodic pallor
-cyanosis -parestheisia -coolness -pain -cold sensitiivity in hands and digits -shows in thumb first -distal embolic events are more sensitive than proximal -pulsitile mass seen at the shoulder -unilateral symptoms -late onset |
|
|
what conditions are associated w/ arterial occlusion?
|
inflammatory conditions-eurger's disease, and takayasu
s syndrome -frostbite-chronic vasoconstriction |
|
|
what is the clinical presentation of buerger's disease?
|
-cold extremity
-parestheis -skin color changes -rest pain -intermittant claudication -gangrene or ulceration -superficial thrombophlebitis |
|
|
fibrolytic agents
|
-steprokinase or unokinase:
has to be given within 48 hours of clots; can cause extensive bruising and bleeding |
|
|
raynaud's disease
|
-condition that affects diastal peripheral lood flow in upper and lower distal extremities
-may also affect ears and nose -blood vessels constrict and reduce blood supply due to cold or emotional stress -vasospasm w/ no underlying disease |
|
|
what are the diagnositic goals for TOS?
|
-determine extent of arterial involvement
-check underlying stenosis of the limb -check for changes in arterial flow w/ postural changes |
|
|
what are the risk factors for a pseudoaneurysm?
|
-patients who have undergone procedures involving arterial cannulation
-trauma -iatrogenic or surgical trauma |
|
|
acute stage of beurger's disease
|
-swollen tense artery w/ edema
-lumen obstructed w/ fresh thrombus -critical limb ishemia - |
|
|
popiteal entrapment
|
-trainsient compresion of the popiteal artery as it courses through the popiteal fossa
FACTORS OF COMPRESSION: -aberrant course of artery -scarring of surrounding structures -anomolous placement of structures |
|
|
what are the signs and symptoms of chronic occlusive disease?
|
-claudication, ishemic rest pain, tissue loss
|
|
|
compartment syndrome: symptoms ad treatment
|
symptoms:
-acute ishemia -numbness and tingling -weakness -pain TREATMENT: fasciotomy |
|
|
what are the signs and symptoms of PSA?
|
-excessive bleeding/swoolen extremity following arterial cannulation
-palpable, pulsitile mass at site |
|
|
blue toe syndrome
|
-may occur w/ microemboli to the smallest vessels of the toes
CAUSES: -ulcerated and or atherosclerotic lessions -embolization -inflammatory process of arteritis -some angiographic procedures |
|
|
what are the symptoms of neurogenic TO?
|
-women 30-59
-history of cerviothoraci trauma -certain activities aggrivate the symptoms(stretching plexus, hyperabduction) -pain along neck, lateral shoulder, anterior chest, or parascapular region -parestheia and numbness in distal extremity |
|
|
what are the complications and general symptoms of arteritis?
|
complications: occlusion and embolization are common
symptoms: -low BP -pale cyanotic limb -bruits -paralysis or mscle wasting -extremeity size difference |
|
|
neurogenic TOS
|
-pain, parestheia, and weakness of the upper limb
-aggravated by overhead posture -symptoms caused by irritation of brachial plexu -most patients(90-95) have this type of TOS -usually 30-50 yrs, and females have it 4 times more often than males |
|
|
arteritis
|
-inflammation of a n arterial wall
-most common is buerger's disease aka. thromboangitis obliterans |
|
|
what are the testing goals for reynaud's disease/phenomenon?
|
-rule out underlying stenosis
-determine vasoreaction to cold -cold test -PPG |
|
|
what are soft tissue anomolies that have to do w/ TO pathogenesis?
|
-anomolous placement of scalene muscles
-scalenus minimus muscle -congenital myofascial bands and ligaments -brachial plexus may be anaomolous |
|
|
what are the goals for diagnosis of Popiteal entrapment?
|
-determine course of popiteal artery
-asses patency -assess doppler waveforms at reast and then w/ plantar flexion -assess for dialation -popiteal aneurysm criteria=>1cm diameter |
|
|
what patients would be at risk for compartment syndrome
|
-post op patients
-vascular repair -surgury/trauma - |
|
|
acute arterial occlusion
|
-caused by embolus, thrombus, or trauma
-6 P's(pain, pallor, paresthesia, puselessness, paresthesia, and polar) |
|
|
arterial TOS
|
-rare
-occurs secondary to compression of the subclavian artery -due to cervical ribs, first ribs, or old clavicle fractures -affected artery may show post stenostic dialation or aneurysm formation -usully present w/ thromboembolic symptoms |
|
|
arterial TOS-complications
|
-permanent lesions and thormboembolic events
-limb thretening condition -due to congential bony anomoly -takes longer to develop than neurogenic and venous TOS(shows up later in life) |
|
|
what are osseous anomolies associated w/ TO pathogenesis?
|
-cervical rib-displaces brackial plexis cranially
-long transverse process of the C7 vertebra-causes direct compression of the plexus -first rib-borders three anatopic spaces which brachial plexis pass |
|
|
how are PSA's managed?
|
-conservative treatment
-douplex ultrasound w/ graded compression -direct thrombin injection |
|
|
what is another name for buerger's disease?
|
thromboangitis obliterans:
-affects males more than females -prevelent in smoking population -reynaud's phenomenon occurs -cessation of smoking causes disease to go away. |
|
|
signs and symptoms of popiteal entrapment?
|
-young athlets
-claudication symptoms -as fibrosis occurs due to comression, stenosis and eneurysms may occur -cramping of the calf and foot -blanching -numbness -unilateral symptoms -palpable pulses at rest but obliteration w/ flexion |
|
|
explain the late stage of buerger's disease
|
-contracted and indurated artery
-may show collaterals |
|
|
secondary reynaud's syndrome
|
-associated w/ an underlying autoimmune disease
-connective tissue disease or fixed obstructive disease -ishcemia is constantly present |
|
|
entrapement syndrome
|
-compression of an artery btw 2 muscles
-popiteal and thoracic outlet syndrome are 2 types |
|
|
what are the disease mechanisms for compartment syndrome
|
-swelling within a confined compartment that compresses vasculature and nerves
-may cause tissue necrosis and embilis |
