What are the 3 things that could be going on in someone who has acute coronary syndrome (ACS)?
1. Unstable angina
2. Non ST segment elevation MI
3. ST segment elevation MI
What is MI
What are the 3 criteria for diagnosing acute myocardial infarction (AMI)?
1. Clinical Presentation
2. Electrocardiogram (EKG or ECG)
3. Elevated biochemical markers of myocardial necrosis
(also look at blood gases (arterial oxygen)
What does clinical presentation tell you?
This does not rule out anything - you could have a silent MI or just really bad angina
What does the EKG tell you?
What percent of heart muscle is gone and distinguishes between NSTEMI or STEMI
What do the biochemical markers of myocardial necrosis tell you?
Measure necrosis (cell death)
Do the biochemical markers of myocardial necrosis tell you about function?
What enzymes/biochemical markers are indicative of myocardial necrosis?
1. Creatine Kinase (CK)
What is creatine kinase?
cellular enzyme used for phosphate group transfer (ATP)
What are the different isoenzymes (and the tissues they reside in)?
1. BB - In the brain
2. MM - Skeletal muscle
3. MB - Heart muscle
After an MI how long does it takes for heart muscle creatine kinase to peak?
What is normal creatine kinase levels?
LESS THAN 5%
What is troponin?
A polypeptide that mediates interation of actin and myosin (requires Calcium)
What are the different troponin polypeptides?
TnC - NOT cardiac specific
Which forms of troponin do you use to identify an MI?
When does Tnl peak?
When does TnT peak?
12 hours - 2 days
How do you diagnose AMI (acute myocardial infarction) - STEP 1?
1. Myocardial tissue damage/necrosis will come with a release of intracellular enzymes and polypeptides.
How do you diagnose AMI (acute myocardial infarction) - STEP 2?
2. CK more than 5% (the # will be like in the 1000's)
Rises: 6-12 hours
Peaks: 24-36 hours
Dec: 1-2 days
How do you diagnose AMI (acute myocardial infarction) - STEP 3?
Rises: 3-6 hours
Peaks: 24 hours
Dec: 7-10 days
How often are blood samples drawn in hospital if patient is suspect to have AMI?
1 time (IN ER)
2 more times over the next 12 - 24 hours (IN ICU)
Are CK and troponin blood samples draw together?
What is diagnostic for MI ?
1 elevated Troponin
2 elevated CK
What does the liver manufacture?
2. Bilirubin (processed in the liver)
3. Clotting factors
What else does the liver do besides manufacture?
What are the liver enzymes that are evaluated in liver function tests?
2. LDH5 (Lactate dehydrogenase - isoenzyme 5)
4. Alkaline phosphatase
5. Albumin (and pre-albumin)
6. PT (prothrombin time)
What are the two types of bilirubin tests?
What is direct bilirubin?
Conjugated with glucuronic acid
= Post hepatic events
What is indirect bilirubin?
=Pre-hepatic (hemolysis) or decreased hepatic function
Why do you look at AST and ALT in liver function tests?
They are very sensitive to hepatic inflammation and necrosis
What 2 diseases or physical states are associated with elevated AST/ALT levels?
1. Acute viral hepatitis
2. Severe drug toxicity
When is ALP usually elevated?
In cholestasis (most often)
also elevated in many other hepatic disorders
What are the two enzymes related to ALP?
LAP AND GGTP (elevated with alcohol use)
Why do we look at albumin levels in liver function tests?
Because the liver makes albumin
What are the 3 functions of albumin?
1. Oncotic pressure
2. AA transport
What is a better test than albumin ?
What is pre-albumin a better test than albumin?
Albumin 1/2 life: 15-20 days
pre-albumin 1/2 life: 2 days
--See what the liver made within the last 2 days, not the last 20 days... more recent knowledge with pre-albumin
What happens to the prothrombin time/INR test in a patient that has liver disease?
It increases above normal range (PT: above 13 seconds; INR: above 2)
Why would the PT/INR increase?
That means that the patients clotting ability has decreased and may be due to liver disease because the liver makes certain clotting factors
What is the normal ranges for PT/INR?
PT: 10-13 SEC