Cardiac Markers Flashcards
(52 cards)
What main tests are used to measure damage to the heart?
total Creatinine Kinase (CK) Lactate dehydrogenase (LDH) Troponin Myoglobin B-type natriuretic Peptide (BNP)
What is the normal range for Creatinine Kinase?
Men: 38-174 U/L
Women: 96-140 U/L
Where is Creatinine Kinase primarily found?
High concentrations in the HEART and SKELETAL MUSCLES
What do measurements of CK specifically indicate?
injury to MYOCARDIUM
MUSCLE TISSUE
BRAIN
What are the 3 isoenzymes of CK?
CK BB - found in the BRAIN, GI, GU
CK MB - found primarily in cardiac muscle
CK MM - found primarily in skeletal muscles
What do elevations of CK-MB generally indicate?
Myocardial Infarction
What do elevations of CK-BB indicate?
Brain injury
What do elevations of CK-MM indicate?
Muscle injury
When drawing serum levels of CK, which isoenzyme should only be present in the blood?
CK-MM
How long does it take for CK-MB to rise in serum levels?
within 3-12 hours after an attack.
it peaks at 18-24 hours
lasts 36-48 hours
Where is Lactate dehydrogenase (LDH) generally found?
It is an enzyme particularly found in the KIDNEY, HEART, SKELETAL MUSCLE, and BRAIN.
What does increases in LDH indicate?
cellular death and leakage of the enzyme from the cell
Which LDH isoenzymes are more specific to the heart?
LD1 and LD2
(however, they are also found in the kidney and the RBCs. This is not the best test for indicating heart damage, and Lucas doesn’t use it very often)
What conditions can elevated LDH indicate?
CHF, liver disease, cancer, lung disease, muscular dystrophy, megablastic anemia, hemolytic anemias, and myocardial infarction
What is the “LD flip?”
where LD1>LD2. This finding, along with increased CK-MB is essentially diagnostic of an MI.
What is Troponin?
complex of 3 proteins that bind to the thin filaments of striated muscle (both CARDIAC and SKELETAL)
What is considered the gold standard for detection of an MI?
Elevated Troponin levels
How long does it take for Troponin levels to increase in the serum?
3-12 hours after MI
peaks at 18-24 hours
can stay elevated for 10 days
What is myoglobin?
An oxygen binding protein of striated muscle.
What are increased levels of myoglobin associated with?
Can indicate MI
How long does it take for Myoglobin levels to increase in the blood?
Faster than Troponin.
1-4 hours
peaks at 6-7 hours
lasts for 24 hours
How reliable are increased levels of myoglobin in the blood to indicate an MI?
It is not specific to the heart, so other muscle injuries will cause serum levels to increase.
How soon should an EKG be done on a patient suspected of an MI?
QUICK! Medicare requires you to do one within 8 minutes to be reimbursed.
How specific are EKGs in detecting an MI?
It is VERY specific.
