Diagnostic Cardiac Blood Tests Flashcards
list non-modifiable risk factors for CHD
- age
- family history of CVD
- gender (specifically male)
list modifiable risk factors for CHD (6)
- HTN
- elevated total cholesterol
- uncontrolled DM
- smoking/components of cigarette smoke
- physical inactivity
- obesity (BMI > 25)
list other/additional risk factors for CHD (5)
- postmenopausal
- high levels of C-reactive protein
- uncontrolled stress
- poor diet
- alcohol use
what values are included in blood lipid profiles (5)
- total cholesterol
- high density lipoproteins
- low density lipoproteins
- very low-density lipoproteins
- triglycerides
what is cholesterol? What does it do in the body?
- a form of fat that is essential to the body
- components of cell walls/cell fluidity
- precursor molecule for:
- vitamin D
- sex hormones
What is a desirable total cholesterol value?
<200 mg/dL
what is borderline high total cholesterol? What about high?
200-239 mg/dL is borderline
>240 mg/dL is high
what is considered the “good” cholesterol?
HDL
- transports cholesterol in the blood and scavenges fats/cholesterol from the blood and returns it to the liver for disposal
normal ranges of HDL
- Men → 40-60
- Women → 50-60
T/F: aerobic exercise has no impact on HDL
FALSE
it can increase HDL concentrations
what is the relationship between ACS and HDL?
the greater the HDL levels the less likely to have ACS (acute coronary syndrome)
what are LDLs?
low density liproteins
- can invade tunica interna of blood vessels and remain → forms atheroma
- creates an inflammatory cascade resulting in the formation of an athersclerotic plaque
describe how LDLs can lead to the formation of an athersclerotic plaque
- LDL invades tunica interna of blood vessel and stays (atheroma)
- WBCs move into this area and establish a low-grade inflammatory situation
- smooth muscle cells proliferate and enter this area
- fibrous CT accumulates
- macrophages are attracted to this area
- forms a swelling in the artery wall (plaque)
T/F: plaque formation is self-propagating?
TRUE
increased LDL → increased plaque formation and increased risk for CV disease
(increasing circulating LDLs increases risk for atherosclerosis)
how is the amount of LDL in the body determiend?
derived/calculated
LDL = Total cholesterol - HDL - triglyceride/5
normal ranges for LDLs
aka fasting values
100 mg/dL or less
(less is better)
What are triglycerides and how are they assocaited with CVD?
- Glycerol + 3 fatty acids = triglyceride
- high levels of triglycerides in the blood have been linked to:
- atherosclerosis and by extension the risk of heart disease and stroke
What are the 2 types of triglycerides?
- Saturated fats
- Unsaturated fats
what are saturated fats?
- Fat molecules that have no double bonds between carbon molecules b/c they are saturated with hydrogen molecules
- solid at room temp
- high levels of saturated fat in blood = increased risk of heart disease and stroke
what are unsaturated fats?
- fat molecules in which there are one or more double bonds in the fatty acid chain
- mono-unsaturated
- polyunsaturated
- low melting point/fluid at room temp
- can be classified as cis- and trans- fatty acid
describe trans fatty acids
- type of unsaturated fats
- uncommon in nature but are commonly produced industrially from vegetable fats
- increased intake associated with increased risk for CVD
describe cis fatty acids
- unsaturated
- generally good for health
- naturally occuring
- chains of carbon atoms are on the same side of the double bond, resulting in a kink
List/describe the ranges for triglycerides
- Normal → <150
- Borderline High → 150-199
- High → 200-499
- Very high (highest risk) → >500
describe cholesterol ratios
total cholesterol/HDL
- the lower this ratio, the lower your risk of heart disease
- recommendations are to keep this ratio to 5 or less
when should screening/cholesterol testing be conducted?
screen all men >35 years old
screen all women >45 years old
List drugs that help manage cholesterol
- stains
- niacin
- PCSK9 inhibitors
List several serum enzymes/cardiac biomarkers
- CPK
- Troponin
- Myoglobin
- LDH
- AST
- SGOT
- ANP
- BNP
- Fibrinogen
- CRP
- Lipoprotein A
- Serum creatinine
list the types of CPK
- CPK-MB → most specific type for myocardial injury
- CPK-MM → skeletal muscle damage
- CPK-BB → brain tissue damage
describe serum CPK trends after injury
- rises → 4-6 hours
- peaks → 12-24 hours
- duration → 4-5 days
- normal range = 0-175 IU/L
what is troponin? Describe the various subtypes
- group of proteins found in striated muscle cells and bound to the actin filament
- TnC → binds calcium
- TnI → inhibits interaction between actin and myosin
- TnT → links troponin complex to tropomyosin
describe serum troponin trends after injury
- rises for about 4-6 hours
- peak concentrations 18-24 hours after symptoms begin
- troponin collected on admission and then 6-9 hours later
- can remain elevated for 10 days after injury
what is myoglobin and where is it located?
- heme protein found in all muscle tissue
- specifically striated muscle tissue
- facilitates the movement of O2 from environment into the muscle cell
how does myoglobin relate to injury?
- recent potential diagnostic tool for acute MI
- can be detected as early as 2 hours after injury
- peaks 3-15 hours after injury
- normal = 25-72 ng/mL
what is ANP?
Atrial Natriuretic Peptide
- peptide hormone of cardiac origin which is released in response to atrial distension
- serves to maintain sodium homeostasis and limits activation of the renin-angiotensin-aldosterone system
- results in vasodilation, diuresis → decreased preload and aferload = decreased workload on the heart
how does ANP relate to heart failure?
increases with increasing severity of HF
inhibits cardiac hypertrophy and fibrosis
what is the gold standard for the measurement of HF?
BNP (brain natriuretic peptide)
where is BNP produced and what does it do?
- produced in the ventricles and released in response to excessive stretch on the heart muscle
- causes
- dilation of blood vessels
- increases sodium excretion and diuresis in the kidney
- reduced release of angiotensin and aldosterone
- net effect → decrease blood volume and BP to promote urine production
- causes
what is the funciton of BNP?
maintain stable BP and plasma volume and to prevent excess salt and water retention
normal values for BNP
less than 100 pg/mL
BNP values that indicate cardiac decompensation
>700 = acute cardiac decompensation
100-700 = chronic cardiac compensation
what is the funciton of fibrinogen?
occlude blood vessels → stop bleeding
if increased there is an increased risk for clot formation and experiencing a hemorrhagic stroke
what is CRP?
C Reactive Protein
- produced in liver and is increased in inflammatory states
- atherosclerosis, CHF, cancer, infections, or liver dysfunction
- measures general levels of inflammation in the body
CRP values and their significance
- normal → <1.0 = low risk
- 1.0-3.0 = high risk
- >10 = evaluated to exclude non-cardiovascular diseases
what is lipoprotein A?
what 4 things is it a risk factor for?
- a lipoprotein subclass
- atherogenic and prothrombotic effect
- high levels strongly associated with atherosclerosis
- independent risk factor for CAD
- risk factor for CHD, stroke, thrombosis
describe serum creatinine
- normal = <1.5
- fully filtered by the kidneys
- blood levels increase as kidney function declines
- or with reduced renal perfusion
- creatinine accumualtes in blood
- HF → decreased CO → decreased renal perfusion
- or elevated serum creatinine may by an independent predictor of cardiovascular mortality
