Lipoproteins and Cardiac Enzymes Flashcards
where is cholesterol metabolized?
liver
what transports cholesterol in the blood?
lipoproteins
why can cholesterol be a problem?
associated with atherosclerotic disease
what is the main function of cholesterol?
production of steroids, sex hormones, bile acids and cell membrane
what can also cause low levels of cholesterol?
liver disease and malnutrition
what coronary predictor is used to identify CAD risk from cholesterol?
Framingham study
what are the 5 major lipoproteins? present on the standard lipid panal
chylomicrons VLDL IDL LDL HDL
what do chylomicrons do?
carry fat from the GI tract to liver, skeletal muscle and adipose tissue
-they are very large particles
what do VLDLs do?
carries endogenous (self-made) triglycerides from liver to adipose tissue carries cholesterol (when it is high it means that there is a lot of endogenous cholesterol)
what do IDLs do?
carries cholesterol esters and triglycerides
-usually not detectable
what do LDLs do?
carries cholesterol esters from liver to cells of the body
what do HDLs do?
collects cholesterol from tissues and vacular endothelium and returns it to the liver
-has a protective effect against heart disease
what is reverse transport?
when HDL takes cholesterol in the vasculature and returns it to the liver
how can we increase HDL?
excersize
what do triglycerides do?
acts as a storage source for energy, when they are high they are deposited in fatty tissues
how are triglycerides transported?
VLDL and LDL
what purposed does the lipid profile serve?
assess CAD risk
assess vascular dz risk
what is on a lipid profile?
total cholesterol triglycerides HDL LDL VLDL HDL/LDL ratio
what are the normal adult TCC values?
<200mg/dl
what is the critical value of TG?
> 400mg/dl
what are the normal HDL values?
m >45mg/dl
f >55mg/dl
what are the normal LDL values?
adult <110mg/dl
what TG value would cause an inaccurate LDL?
> 400mg/dl
what is the normal range of VLDL?
7-32mg
how do you calculate LDL?
TCC-(TG/5-HDL)
what instructions are important for lipoprotein study?
12-14 hr fast
low fat meal prior to fast
what can interfere with cholesterol levels?
pregnancy increases levels
recumbent positions decrease levels
postmenopausal states cause increased levels
what can impact HDL levels?
age/sex
post MI decreases
smoking decreases
liver dz and malnutrition decreases
hyperthyroid decreases
hypothyroid increase
binge eating
main drugs that alter lipoprotien
beta blockers alpha blockers dilantin steroids estrogens
what are the normal values of CK?
m 55-170 u/L
f 30-135 u/L
If the pt is not having a coronary event, what will the total CK reflect?
CK-MM (skeletal muscle)
when would CK-MB be greater than 0?
pt is having a cardiac event
when would CK-BB be greater than 0?
pt is having something going on
brain assoc. CK problem
why use CK?
support dx of MI
can also indicate neurological and skeletal muscle dz
when can total CK rise?
within 6 hrs of damage
when will total CK return to normal?
peaks at 12-24 hours and returns to normal 2-3 days after infarction
when would CK-MB be slightly elevated and this would be normal?
marathons, triathalons
severe crush injury
what else can indicate myocardial injury?
LD within 24-48 hours
why do they no longer use LD?
it takes too long to see an elevation in the levels
what will cause a false high LD level?
hemolysis
strenuous exercise
what is the normal troponin T
<0.2 ng/ml
what is the normal troponin I
<0.3ng/ml
what are troponin levels used for?
determine if CP is caused by cardiac ischemia
early risk stratification for pts with unstable angina
what does troponin test mean?
biochemical markers for cardiac dz
why use troponin instead of CK?
elevates sooner (3hrs) and remains elevated longer more sens and specific (CK can't differentiate ischemia)
why do you put date and time on test tube for cardiac enzyme tests?
know when to perform serial values
when are troponin T levels falsely elevated?
pts with renal heart failure
what marker increases in response to ventricular wall stress?
Btype natriuretic peptide (BNP)
useful prognostic indicator change over time
what is the use of CRP?
evaluate cardiac risk profile
considered to be related to cardiac atherogenesis
