Exam 3: Sec. 4: Vascular Pathologies Pt2 Flashcards
What is atherosclerosis defined as?
the presence of athersclerotic plaques, formally known as atheromas, that develop within the tunica intima and cause stensosis of the vascular lumen
About how many deaths in the U.S. is atherosclerosis ass. with?
about half!!
What diseases does the vascular stensosis caused by atherosclerosis lay at the core of?
- coronary artery disease
- heart attack
- cerebral vascular disease
- stroke
- peripheral vascular disease
How do atherosclerotic plaques effect nutrients getting to the vessel?
reduce the diffusion to the inner half of the tunica media
What do atherosclerotic plaques increase the risk of?
aneurysms and vascular disruption/hemorrhage
What is the combination of macrophages and lipids w/in an atheroma known as?
foam cells
What happens if an atherosclerotic plaque ruptures?
the foam cells and other debris combine with circulating blood and cause vascular occlusion, via formation of excessive thromboemboli
What do we call atherosclerotic plaques that are ass. with greater levels of inflam. and have a thinner outer fibrous cap?
vulnerable plaques–> are more prone to rupturing
What do vulnerable plaques contain greater amounts of?
- macrophages
- lymphocytes
- degradative matrix metalloproteinases (MMPs)
What is the MC cause of Myocardial infarction?
ruptured atherosclerotic plaque
When atherosclerotic plaques rupture, what may they be referred to as?
“erosion”, “ulceration”, “fissuring”, of a plaque or even “acute plaque change”
What represents atheromas with lower levels of inflammation and are less prone to rupturing?
stable plaques
What is coronary artery disease defined as?
70% occlusion or coronary arteries
When it comes to the Epidemiology of Atherosclerosis, what areas of the world have higher rates of atherosclerosis, what areas have lower rates?
higher–> U.S.–> due to exposure to Standard American Diet
lower–> Japan
What is the Standard American Diet?
(SAD) High levels of: - processes meat - red meat - fried foods - high fat - refined grains - high sugar drinks - high-fructose corn sytrup
Where are rates of atherosclerosis highest in the world? What age group?
among Americans–> over 70 years of age have sig. levels of atheroslcerosis w/in larger-to-medium sized arteries
How are the risk factors for atherosclerosis commonly classified?
- Inherent/ non-modifiable (constitutional)
2. modifiable
What are some constitutional risk factors (non-modifiable) for atherosclerosis?
- family history
- familial hypercholesterolemia
- over age 40
- male sex
Describe the risk of atherosclerosis of males and females.
males have higher risk earlier in life than females, and it increases gradually from there
females risk approaches that of males when they are postmenopausal
What are some Modifiable Risk factors for atherosclerosis?
- consumption of omega-3 FAs = good
- regular physical exercise
- consume 1-2 alc drinks per day
Increases risk:
- hypercholesteremia (major risk factor)
- consumption of trans fats
- prolonged HTN
- smoking tobacco
- systemic inflam.
- metabolic syndrome
- diabetes mellitus
What are all risk factors for atherosclerotic plaque formation thought to contribute to?
development of atherosclerosis via “response-to-injury” hypothesis
What do the various risk factors of atherosclerosis cause?
- *endothelial injury
- inflam.
- thickening of tunica intima
- accumulation of foam cells, cellular debris, lipids
- dytrophic calcification
Can hemodynamic stressors contribute to atheroma formation?
yes–> include turbulent blood flow at site of previous site of atheroma, branch points, or structural irregularities on inside of vessel wall
What four clinical consequences is Atherosclerosis ass. with?
- Cardiovascular complications
- Metabolic Syndrome
- Peripheral Vascular Disease
- Aneurysms
What are the three most clinically significant consequences of atherosclerosis?
- coronary artery disease
- MI
- CHF
- -also cerebral infarction
What are the top 3 risk factors for M.I.? What is ones risk if they have 2 or them? What about 3 of them?
- Hyperlipidemia
- HTN
- Smoking
- -any 2 = 4-fold increase
- -any 3 = 7-fold increase
By what fold does having a history of diabetes mellitus increase ones risk of of a myocardial infarction?
2 fold
What do most cardiovascular complications from atherosclerosis involve?
a ruptured atheroma and a sudden occlusion of blood vessels supplying heart or brain
What is an occlusion of 70% of more of a vessel’s cross-sectional space known as?
critical stenosis
What is the point at which coronary artery disease begins to cause angina pectoris (chest pain)?
at critical stenosis (70% occlusion)
What may critical stenosis of the arteries supplying the brain cause?
TIAs (transient ischemia attacks)
What is Metabolic Syndrome?
(previously Syndrome X)
- combination of separate conditions that occur together and increase ones risk of developing cardiovascular disease and type 2 diabetes mellitus
What are the 5 criteria that one must have 3 of to be diagnoses with Metabolic Syndrome?
- Central (visceral) obesity
- Hypertension
- Dyslipidemia
- Insulin resistance
- Pro-inflammatory state (hypercoagulability)
What is a generic term for disease processes that affect the vessels of the “periphery”, which are not vessels supplying heart and brain?
Peripheral Vascular Disease
–vessels usually in extremities or other organs
What most likely causes Peripheral Vascular Disease?
atherosclerotic narrowing–> cause peripheral ischemia
rarely from embolism or prolonged spasm
What are the risk factors for Peripheral Vascular Disease? What are the the most sig. ones in the U.S.?
same as atherosclerosis
in U.S.–> smoking and diabetes mellitus
What vessels are most likely to develop Peripheral Vascular Disease? What is the painful cramping sensation that may develop called? What worsens the cramping?
vessels of lower extremities
claudication (vascular claudication)–> exercise worsens it
How may Peripheral Vascular Disease manifest?
- claudication
- pale discoloration
- gangrenous necrosis in severe cases
What is the treatment for Peripheral Vascular Disease?
lifestyle modifications, such as:
- smoking cessation
- strict glucose control among diabetics
- regular physical activity
- improved dietary choices
–rarely surgical angioplasty and bypass grafts may be needed
What is a congenital or acquired localized dilation of an arterial wall called?
an aneurysm
“ballooning” of the arterial wall
How will an aneurysm affect the vessel wall?
- increase tension on dilated/weakened wall–> risk of vascular rupture and hemorrhage
- site for vascular stasis or turbulance
What layers of the vessels wall do the majority of aneurysms involve? What are they referred to as?
all 3 layers (tunica intima, media, adventitia)
= “true” aneurisms
Rarely, an aneurysm may allow blood to escape and form a dilated hematoma that is only 1 or 2 vascular layers, when this occurs what do we call it?
“false” aneurysm
or a pseudoaneurysm
What are the two MOST significant risk factors for developing an aneurysm? What are other causes?
- atherosclerosis
- hyperextension
- physical trauma, vasculitis, congenital defects