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Unformatted text preview: * **Arteriosclerosis ***is a thickening or hardening of the arterial wall. Atherosclerosis involves the formation of plaque within the arterial wall and is the leading contributor to coronary artery and cerebrovascular disease Formation of plaque- after the vessel becomes inflamed, a fatty streak appears on the intimal surface of the artery. Next, a stable or unstable plaque develops. ( stable- fibrous elevation that covers a lipid core, Unstable- plaque has a liquid lipid core). Finally, the =fibrous lesions become calcified, hemorrhagic, ulcerated, or thrombosed and affect all layers of the vessel Theories- 1. Injury to the intimal (innermost) layer : platelet aggregation- after intimal injury occurs, platelets form a cluster at the arterial wall and produce a peptide that stimulates the proliferation of the smooth muscle cells of the intima =compromise the flow of blood or completely occlude arterial blood flow 2. lipid hypothesis- after an intimal injury, a group of blood lipids accumulate Intimal injury attributed to: 1. HTN- mechanical injury 2. elev LDL and dec HDL can cause chemical injuries to the intimal wall 3. Chemical injuries- elev toxins in blood stream- occur with renal failure or CO circulating in blood stream from cigarettes 4. Intimal wall weakened by aging or Diabetes 5. hyperlipidemia- liver makes excessive cholesterol and other fats Assessment- 1. Because of high incidence of HTN, assess BP in both arms 2. palpate pulses at all major sites 3.palpate temp. diff in lower extremities and check capillary refill 4. may have a bruit- turbulent, swishing sound, can be soft or loud in pitch Lab assessment- Normal: total cholesterol <200mg/dl; LDL <100mg/dl; HDL >40mg/dl *Inc LDL indicate inc risk for atherosclerosis; low HDL may indicate risk 1 *High homocysteine (seen in PVD, CAD, stroke and venous thrombosis)- high levels block production of nitric oxide on the vascular endothelium making the cell walls less elastic and permitting plaque to build up. Elev levels may be lowered by diet with B-complex vit., esp. folic acid Diet- *encourage folic acid (cereals), B6, B12, add multivitamin if diet does not lower homocysteine levels *dec saturated fats- meat, palm and coconut oils, and eggs are sat fat. Suggest- safflower and sunflower oils, canola * stop smoking- smoking lowers levels of HDL and inc rate of progression of atherosclerosis * exercise- can lead to regression of atherosclerotic plaque and the building of collateral circulation in ppl with atherosclerosis * drugs- statins (zocor, Lipitor, crestor) reduce cholesterol synthesis in the liver and inc clearance of LDL; zetia- inhibits absorption of cholesterol through the small intestine ***PVD*** Definition Peripheral vascular disease is a narrowing of blood vessels that restricts blood flow. It mostly occurs in the legs, but it is sometimes seen in the arms....
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- Spring '08