Cardiology Labs Flashcards
Myocardial Response
Loss of critical blood supply to the myocardium
Decreased ATP and increased lactate accumulation
Loss of contractility
Myoglobin indications?
Early evaluation of pts with suspected AMI
Also used for disease/injury of skeletal muscle
(< 90 mcg/L)
Myoglobin is an __ binding protein found in _______ and ________ muscle?
O2
cardiac
skeletal
Myoglobin is more sensitive than ___________ but it is not as specific.
phosphokinase isoenzymes (CPK)
Myoglobin can be found in _____ and can turn it ___.
urine
red
use a urine dip stick - its the myoglobin that is turning it positive
Decreased myoglobin levels ?
Polymyositis: pts have antimyoglobin ab
Increased myoglobin ?
1-3 hrs after MI - soon - elevation occurs first
Peaks 6-9 hours after muscle injury
Skeletal muscle inflammation/ischemia/trauma
Rhabdomyolysis - muscle wasting -
to much exercise
Prolonged seizure - skeletal muscle damage
cells in cardiac muscle or skeletall muscle lyse and release myoglobin
How much time until myoglobin peaks?
6-9 hrs after muscle `
Creatine Kinase (CK, CPK) normal Values males and females?
Male: 55-170 units/L
Female: 30-135 units/L
Creatine Kinase (CK, CPK) normal Values newborn?
68-580 units/L
Creatine Kinase (CK, CPK) Isoenzymes?
CK-MM: 100%
CK-MB: 0%
CK- BB: 0%
most of CK found in skeletal muscle
BB- brain
MM- muscle
MB - muscle brain - heart
Creatine Kinase (CK, CPK) indications?
Support the diagnosis of MI
Indicate neurologic damage
Indicates skeletal muscle disease
Hemorrhagic stroke patho?
Hemorrhage/blood leaks into brain tissue
Ischemic Stroke patho?
Clots stops blood supply to an area of the brain
CK levels rise when _____, _____, or ________ muscle is damaged?
brian
heart
skeletal
CK rises within _ hours?
6
CK peaks at __-__ hours?
18-24
CK normalized - days?
2-3
Interfering factors of CK?
IM injections
Strenuous exercise
Recent surgery
Large muscle mass - elevated
CK all the time
Drugs (ETOH, AC, ASA, Lasix,
Decadron, morphine)
Creatine Kinase (CK, CPK) increased when?
Any injury to heart, brain, or skeletal muscle
Increased CK-BB
Electroconvulsive therapy
Adenocarcinoma - they do not know why
Pulmonary infarction - small amount in lung tissue
Brain injury (CVA, hemorrhage, seizures, shock, brain cancer)
Increased CK- MB:
AMI/cardiac ischemia
Cardiac surgery/defibrillation
Myocarditis
Others: severe skeletal injury, lung injury, or renal failure
Increased CK- MM?
Rhabdomyolysis MD Myositis Skeletal trauma/surgery IM injections Myositis
skeletal muscle
Troponin T (cTnT) normal level?
<0.2 ng/mL
Troponin I (cTnT) normal level?
< 0.03 ng/mL
Troponin are proteins that exist within ________ and _______ muscle that regulate the _______ dependent part of muscle contraction
skeletal & cardiac
calcium
Which troponin binds to calcium?
Troponin C
What are the two troponin that are cardiac specific?
Troponin T & Troponin I
Troponin is so specificc that nothing else can really elevate it besides a MI
Disadvantage with troponin?
Falsely elevated in dialysis or renal failure patients
Advantages with troponin?
Highly specific to myocardial cell injury
Will be normal with non-cardiac muscle disease
Elevated sooner than CK (within 3 hours)
Remain elevated longer
T: 10-14 days
I: 7-10 days
How long does troponin T stay elevated for?
10-14 days
How long does troponin I stay elevated for?
7-10 days
Is troponin elevated sooner than CK?
Yes , troponin is elevated after 3 hours, CK takes 6 hours
Indications for troponin?
Unstable angina
Detection of reperfusion after recanalization
Estimation of MI size - troponin will be higher if more damage
Detection of perioperative MI
Evaluate severity of PE - b/c ischemia
Evaluate severity of CHF - damage to the ventricles from continuous heart strain
When is troponin increased?
MI
Myocardial injury
LDH ( lactic dehydrogenase) normal levels?
Adult: 100-190 units/L
LDH isoenzyme 1?
herat, RBC
LDH 2?
heart lung, reticuloendothelial system
LDH 3?
lung
LDH 4?
kidney, pancreas, placenta
LDH 5?
skeletal muscle, liver
When do we see a flipped LDH?
when someone is having a HA, LDH 1 is more sensitive and rises above LDH 2 ( usually LDH 2 is grater than LDH 1)
A total LDH will include all the isoenzymes which will be ________ with a different process?
elevated
LDH explanation?
During MI cells lyse and spill LDH into the blood stream
When LDH 1 rises above LDH 2 this indicates myocardial injury (“flipped LDH”)
Appears within 12-24 hours
When does LDH start to appear?
12-24 hours
Indications for LDH?
Diagnosis of injury: Heart Liver RBCs Kidneys Skeletal muscle Lungs
What are some factors that interfere with LDH?
Hemolysis of blood
Strenuous exercise
Drugs:
Increase: ETOH, ASA, narcotics, procainamide
Decrease: ascorbic acid
Drugs that increase LDH?
ETOH, ASA, narcotics, procainamide
Drugs that decrease LDH?
ascorbic acid
When will we see increased levels of LDH?
MI (LDH1 over LDH2)
Pulmonary disease (LDH 2 & 3)
Hepatic disease (LDH 5)
Skeletal muscle disease
Intestinal ischemia (LDH 5)
Neoplastic states - b/c the way they spread
Pancreatitis (LDH 4)
Highly sensitive CRP normal levels with cardiac risk?
Cardiac Risk:
Low: <1.0 mg/L
Average: 1.0-3.0 mg/L
High: >3.0 mg/L
Indications for hs-CRP?
Indicates inflammatory illness
Bacterial infections
used to look for maybe a smoldering infection - follow CRP during treatment and watch it tank if infection is going away - get a baseline
When do we see increased levels of hs-CRP?
Inflammatory reactions
Collagen-vascular disease
Tissue infarction or damage
Bacterial infections
Malignant disease
Post-operative wound infections
Risk of cardiovascular events
Interfering factors for hs-CRP?
Cigarette smoking (b/c body is responding to salt)
Medication (estrogens and progesterones)
HTN
Metabolic syndrome/ increased
BMI/DM
Chronic inflammatory conditions
Decreased levels for hs-CRP?
Fibrates, niacins, statins
ETOH consumption
Endurance exercise
Weight loss
CRP and cholesterol ratios?
High CRP but LOW LDL then still high chance of HA ( CRP trumps)
Is hs-CRP used in acute MI?
NO
Why is hs-CRP very non-specific?
elevated in anyone that has inflammation in the body
C-reactive protein
Normal ESR (Erythrocyte Sedimentation Rate, Sed Rate) levels?
Male :< 15
Female: <20
What does ESR measure?
measure the rate the RBC settle or sediment
is it important b/c if we have inflammation we have increased proteins and the RBC stack up faster
Is ESR non specific?
Yes, like hs-CRP
ESR explanation?
The rate at which RBCs settle in saline solution or plasma over a specific time period
Increase in protein (fibrinogen) content of plasma making them stack up on each other and increases weight causing them to fall faster
Indications to us ESR?
Acute/chronic infection
Detect illnesses
Collagen-vascular disease
Advanced neoplasm
Tissue necrosis/infarction
Interfering factors for ESR that cause it to decrease?
Specimen allowed to stand >3 hours
Drugs (ASA, cortisone, quinine)
Sickle Cell Anemia
Spherocytosis
Interfering factors for ESR that cause it to increase?
Pregnancy - 2, 3 trimesters when uterus is more stretched
Menstruation
Increased proteins (Macroglobulinemia) - increased RBC content as well
Drugs (theophylline, vitamin A, OCP)
True increased results for ESR?
Chronic renal failure
Malignant disease
Bacterial infections
Inflammatory disease
Necrotic diseases (MI)
Disease with increased
proteins
Severe anemias (lower RBC volumes) - Fe deficiency and Vit. B12 - because they have lower volumes cause lower hemoglobin content
what is AST?
Aspartate Aminotransferase
Normal AST levels?
0-35 units/L
where is ALT mostly found?
liver
AST is found in highly _________ tissue
metabolic
you can test AST 4 days out and it will still be elevated if you has an MI
AST is related to MI and cardiac by?
Directly related to how many cells were affected by the injury
> 5x normal levels in MI - and especially when the ALT is not elevated
BNP means?
Brain Natriuretic Peptide
misnomer - it is not in the brain - its a good marker for CHF cause it is an indicator of muscle wall stretch
Normal BNP levels?
Normal : <100 pg/mL
Critical BNP levels?
Critical value: >100 pg/mL
Explanation in BNP?
Dilates blood vessels
Lowers BP
Responds to volume overload
Released in response to the stretch on the atria and ventricles
Correlates well to left ventricular pressure
early CHF we may not have dyspnea or edema cause the heart is compensating but we can still find an elevated BNP indicating a stretch of the right side of the heart but just has no effect yet case the heart is compensating
Late CHF the heart can no longer compensate so we get edema, and dyspnea and also an elevated BNP
Interfering factors with BNP?
Higher in healthy women
Higher in older patients
Post-op cardiac surgery
When will we see an elevated BNP?
CHF
MI
Systemic HTN
Heart transplant rejection
AMA means?
Antimyocardial Antibody
normal AMA is?
Negative
when is AMA used?
Used to detect an autoimmune source of myocardial injury by using indirect immunofluorescence (IFA)
When do we get increased AMA levels ?
RAC
Rheumatic heart disease - own body attacking tissue
After MI (Dresslers Syndrome) body can attack the damage cause by the MI- swelling and inflammation in pericardium it can also happen after surgery as well ( associated with infarction or trauma)
Cardiomyopathy - not sure why - but ABS are attacking heart tissue
