Arteriosclerosis and Hyptertension Flashcards
What is an atheroma
accumulation of degenerative material in the inner layer of artery walls
Define arteriosclerosis
hardening of the arteries
they become thick and stiff
How is atherosclerosis characterized?
by atheroma in large or medium arteries
-it’s a specific type of arteriosclerosis
Monckeberg’s medial calcific sclerosis
medial calcification WITHOUT luminal narrowing or intimal disruption –> occurs when you get calcium deposits in muscle walls
Hyaline arteriosclerosis
examples
thickening of the basement membrane
ie hypertension and diabetes mellitus
Hyperplastic/proliferative arteriosclerosis
fibrocellular intimal thickening
i.e. - malignant hypertension and scleroderma (chronic hardening of skin and CT)
Non-modifiable risk factors for atherosclerosis
age - risk of MI increases 5X in men 40-60 yrs old
gender - men > premenopausal women
genetics - MOST IMPORTANT FACTOR
Potentially modifiable risk factors for atherosclerosis
smoking - 1 pack per day increases death rate by 200%
-once one stops, gradually decreases
diabetes mellitus
hypertension - no specific level identifies increased risk
hypercholesterolemia - higher LDL and cholesterol, the greater the risk. higher the HDL, the lower the risk
Additional risk factors for atherosclerosis
inflammation (C-reactive protein) hyperhomocysteinemia - inc in levels of homocysteine lipoprotein (a) levels metabolic syndrome (obesity) type A personality (stress) lack of exercise
Common sites of atheroma formation
branches of main arteries papliteal artery - knee coronary arteries - heart abdominal aorta carotid arteries - head and neck cerebral arteries - brain
What does plaque contain?
collagen lipid macrophage myofibroblasts neovascularization (proliferation of bv in tissues not normally containing them)
What makes up a fibrous cap?
myofibroblasts (smooth muscle cells) and collagen.
these cover a central core of lipid/cellular debris with CHOLESTEROL
Plaque can progress into…
ulcerations
fissure formation
thrombosis
embolization of thrombus or debris from central core
calcification
hemorrhage into plaque from neovascularization
What is a fatty streak?
the first grossly visible lesion in the development of atherosclerosis
-characterized by lipid-laden cells in the intimia
Where do fatty streaks occur?
in infants and children in atherosclerotic or nonatherosclerotic areas
What can result from a fatty streak?
they can regress
or
they can progress to atheromas
complications of atherosclerosis
ischemic heart disease - reduced BF to <3
aneurysm formation due to pressure atrophy of the media with altered balance of collagen synthesis/degradation
hypertension prevalence in adults from USA?
about 25%, prevalence increases with age
guidelines for hypertension
BP < 140/90 –> normal
BP > 160/106 –> moderate to severe
BP = 140/90 to 159/104 –> mild
What does essential hypertension mean?
It accounts for what % of hypertension?
hypertension without a known cause
90%
Contributing factors to essential hypertension include:
genetics obesity stress increased salt inactivity cigarette smoking
Symptoms of essential hypertension
most patients have no symptoms until organ damage has occurred
High BP causes:
headache
dizziness
fatigue
palpitations
Concentric left ventricular hypertrophy (compensated)
LV thickens to adapt to inc in stress to wall. Provides normal CO
LV hypertrophy (decompensated) occurs when?
when the LV is no longer able to adequately provide normal CO
what does LV hypertrophy (decompensated) lead to?
dilation and CHF
Atherosclerosis leads to…
ischemic heart disease
stroke
ischemic injury to other organs (nephrosclerosis)
gangrene - dead tissue
Arteriosclerosis leads to…
retinal injury (visual disturbances) kidney damage or nephrosclerosis (renal failure)
How does a dissecting hemotoma of the aorta occur?
a longitudinal tear in the media because of a complication from hypertension
Pathogenesis of hypertension
BP = CO x peripheral resistance
- peripheral vascular resistance (vasoconstriction)
- reduced sodium excretion –> salt and water retention –> increased plasma volume and CO
How is secondary hypertension controlled
it’s controlled when the underlying disease is controlled
Relatively rapid onset of very high BP is….
malignant hypertension
Complications stemming from malignant hypertension…
cerebral edema with papilledema ->blindness cerebral hemorrhage retinal hemorrhage severe headache vomiting convulsions encephalopathy - brain disease renal failure heart failure
How does one treat malignant hypertension?
promptly, but being cautious of not decreasing BP too quickly
