B3W1 Flashcards
Three layers of blood vessels and what type of cells is each one
tunica intima (endothelial) , tunica media (VSMC) , tunica externa (fibrous layer)
What is artherosclerosis
deposits of plaques in blood vessels
Where do fatty streaks accumulate
tunica intima
What are fatty streaks made of
cholesterol
if a plaque ruptures then there is …….
myocardial infarction
What are foam cells
macrophage cells which engulf cholesterol
What is atheroma and why is it important
fatty substance that lines the tunica intima and degrades tissue, this is important because it is the first step to diagnosing atherosclerosis
High risks for atherosclerosis
necrotic cores, TCFA, spotty calcifications, remodeling
Anatomical vascular imaging (general list of non invasive and invasive)
Non-Invasive:
Carotid Intima Media Thickness (ultrasound)
Carotid Plaque (ultrasound)
Coronary Angiography (CCTA)
Invasive:
Intravascular optical conherence tomography (iOCT)
intravascular ultrasound (IVUS)
coronary angiography (ICA)
Functional Testing Vascular Imaging (general list)
Non invasive:
BART (brachial artery reactive testing):
Flow mediated dilation (FMD)
hyperemic flow (via ultrasound)
myocardial perfusion imaging (SPECT)
invasive:
fractional flow reserve (FFR)
How does ultrasound anatomically test
used for structure not the fx, aids in detection of plaques and presence, Carotid intima media thickness (higher IMT, higher risk)
Best vascular anatomical imaging resolution
iOCT > IVUS > ICA
3 types of BART and what are they used for
uses ultrasound to measure diameter and velocity of flow through artery
flow mediated dilation, flow independent dilation, hyperemic velocity
Flow Mediated Dilation
non invasive functional testing:
-BP cuff occludes vessels for 5 minutes leading to local ischemia in the hand
-there is local dilation of vessel because of metabolites being released
-cuff is then released and blood rushes to the hand allowing for sheer stress to cause vasodilation
-if there is high after occlusion dilation = healthy
-if there is low after occlusion dilation = increased risk of CV disease and indicates dysfunctional epithelium
Flow independent dilation
non invasive functional testing
nitroglycerin is administered into artery to see local dilation
-sees a higher response than FMD
Hyperemic velocity
non invasive functional testing
measures microvascular endothelial function
Invasive coronary angiography (ICA) (general)
invasive functional testing imaging
uses vasoactive compounds to measure and monitor endothelial activity
what does ACh do in invasive coronary angiography
-causes vasoconstriction of areas with endothelial dysfunction because there is a decrease in ability of endothelial cells to produce NO
-therefore Ach is inducing Gq pathway which leads to constriction
-healthy tissue would allow for normal dilation
-area which did not respond to Ach can be treated with nitroglycerin to aid in dilation
SPECT - what does it do
non invasive functional testing
used to see myocardial perfusion
SPECT - how does it work
non invasive functional testing
-inject Sestamibi tracer (vasodilator that simulates exercise)
-defects in perfusion are seen during exertion (rest v exercise)
-Measure:
– @ rest: perfusion occurs at a more dilated state because vessel is making up for the stenosis by increasing baseline dilation
– @ exercise: when there is an increase in metabolic demand, vasodilation will occur and other arteries will change size to accommodate for demand, but the occluded artery will already be at full dilation and will not be able to grow
Fractional Flow Reserve - what does it do
invasive functional testing
measures the blood flow and pressure in specific area and makes a ration of maximal flow
EQ for fractional flow reserve
measuring two sides of a plaque
Pd/Pa (probe distal/probe anterior) = (flow after stenosis / flow before stenosis)
Values: if FFR is low = stenosis of vessel = increased risk of CV disease
what is the normal FFR value
FFR = > 0.80
FFR is the current standard for …..?
guiding stenting decisions
