Lipid and Cardiac Function Tests Flashcards
4 major lipoproteins
- chylomicrons
- VLDL
- LDL
- HDL
chylomicrons
synthesized in the wall of small intestine and liver
formed in epithelial cells and enter circulation
transfer TGs to adipose and skeletal muscle cells
synthesizes VLDL or used in bile excretion
cholesterol and triglyceride are insoluble in plasma so….
must be broken down for absorption
must be encapsulated by lipoproteins for transport
VLDL
made be taking remains TGs, FFAs, and cholesterol in liver
primary pathway for transport of TGs made in liver
either recycled or converted to LDL
LDL
main carrier of cholesterol
clearance dependent on LDL receptors in adrenal cortex and gonads
40% used to make cell membranes and steroid hormones
60% used to make bile acids and other free cholesterol or reabsorbed into circulation -
LDL and scavenger receptors
Macrophages pick up picked up excess LDL causing foam cell formation
foam cells cause atherosclerosis
HDL
primarily produced and released by liver
reverses transport of cholesterol back into the liver
inverse relationship between HDL and atherosclerosis
total cholesterol numbers
normal, borderline, high
in serum:
desirable <200
boderline 200-239
high >240
only non fasting lipid profile
total cholesterol
total triglyceride serum levels
normal, borderline, high
normal <150
borderline high 150-199
high 200-499
very high 500
elevated triglycerides are considered an independent risk factor for
coronary artery Dz
also a major risk factor for pancreatitis
VLDL normal ranges
5-40
HDL
less than 40 is bad - risk of heart disease
> 60 is protective
LDL ranges
optimal is less than 100
high is 160+
myoglobin
released with muscle injury
non specific for skeletal or cardiac
Creatine Kinase
intracellular enzyme that splits to create phosphate in presence of ADP, yields creatine and ATP
found in cardiac, skeletall, brain
isoenzyme used for MI
Ck-MB
CK-MB post MI serum levels
appears 4 hrs after infarction
peaks at 12-24 hrs post MI
eclipse over 48-72 hrs
troponin
more sensitive and more specific for cardiac damage
not found on any skeletal muscle
Marker of choice
troponin I levels
become detectable 4-6 hrs post MI
peaks then falls and is elevated at low levels for 7-10 days
lactate dehydrogenase
catalyzes oxidation of late to pyruvate
found in all tissues so just suggests injury to muscles, liver, hemolysis, or rapid cell division
not often used bc so nonspecific
what marker is used to asses vascular inflammation and CV risk stratification
CRP
CRP
increases when inflammation occurs
very sensitive but non specific marker of inflammation
Patients with high hsCRP are more likely to develop
stroke, MI, severe peripheral vascular disease so it is used to stratify risk
BNP elevation
found in hypervolemic states such as congestive HF
used in serial monitoring of CHF
BNP clinical application
used in CHF to:
determine cause of symptoms
estimate degree of severity
estimate risk of progression
