Cardiac Markers Flashcards
average weight of the heart
men: 325 grams
women: 275 grams
outermost layer of the heart
epicardium
middle layer of the heart
myocardium
inner layer of the heart
endocardium
layer most susceptible to ischemia
endocardium
where heart tissue is slowly or suddenly starved of oxygen and other nutrients
ischemia
double-layered membrane that encloses the heart
pericardium
R/L valves contract closing mitral valve, aortic valve opens
systole
relaxation phase, tricuspid/mitral valves open moving blood from atria to ventricles
diastole
function of heart
pumps blood to organs, delivers oxygen and nutrients where needed, removes waste products
reduced contraction and relaxation, decreased pumping ability. (ex. Congenital, Hypertension, damage from MI)
(heart disease category)
mechanical defects
electrical defects
irregularities in heartbeat (arrhythmias)
plumbing defects
atherosclerosis, increased cholesterol buildup, decreased blood flow, ischemia
congenital conditions
abnormalities arising from abnormal formation pf heart/blood vessels present at birth
signs of congenital heart condition
cyanosis, pulmonary hypertension, clubbing of fingers, embolism, reduced growth, syncope
causes of congenital heart conditions
maternal rubella infection, maternal alcohol abuse, drug treatment, genetics
rheumatic heart disease
complication of rheumatic fever from group A streptococcus
infective endocarditis
infection of endocardial surface of the heart by bacteria
pericarditis
inflammation of the pericardium
bacteria, fungi, viral, autoimmune
myocardial infarction, angina, heart failure
coronary heart disease
stroke
cerebrovascular disease
acute pain, arms and legs
peripheral arterial disease
aneurysm
aortic atherosclerotic disease
4 categories of cardiovascular disease
coronary heart disease
cerebrovascular disease
peripheral arterial disease
aortic atherosclerotic disease
Criteria for Acute Myocardial Infarction (AMI)
- major rise in troponin (99th)
- ischemia
- ECG changes
- new loss of myocardium
- thrombi
plaques of cholesterol deposit in artery walls, leads to ischemia
atherosclerosis
symptoms of artherosclerosis
chest pain, nausea, vimiting, dyspnea, diaphoresis, light headedness
heart attack is more professional known as
myocardial infarction
first stage of artherosclerosis
vascular injury caused by hypertension, hyperlipidemia, hyperhomocysteinemia
second stage of artherosclerosis
increased permeability to lipids (LDL, VLDL) –> inflammation
3rd stage of artherosclerosis
monocytes and leukocytes arrive to help
fourth stage of artherosclerosis
macrophages scavenge LDL/cholesterol-rich-lipoproteins become foam cells
fifth stage of artherosclerosis
foam cells promote lesion progression
sixth stage of artherosclerosis
T and B lymphocytes are recruited by plaque
seventh stage of artherosclerosis
interactions between t and b lymphs and foam cells recruits smooth muscle cells into lumen
final stage of artherosclerosis
smooth muscle cells secrete collagen, elastin, and other proteins to fix plaque to the vessel wall (atheroma)
cardiac markers
CK-MB, Troponin, myoglobin, myeloperoxidase, BNP, NT-ProBNP
BNP, NT-ProBNP
congestive heart failure markers
historical cardiac enzymes
CK, AST, LD, LD isoenzymes, CK-MB activitiy
how coronary artery disease progresses
lipids, hs-CRP, cardiac markers
characteristics of ideal cardiac markers
- smaller = faster
- specificity
- release from myocardium complete following injury
- remain elevated
- cleared rapidly (allow diagnosis of recurrent injury)
- quick/easy assays
MICAL
Mical had (MI). His (CK) rose first, followed by (A)ST, and lastly, (LD)
Balloon angioplasty and stents
- guide wired inserted
- inflate balloon
- take out balloon, stent is left behind
CK-MB limitations
- 2 assays
- slower, may require dilution
- not always diagnostic
- no increase in activity is found in heart failure
relative index ref range
<3% = normal >6% = cardiac source
consists of three proteins that bind to thin filaments (actin) of cardiac and skeletal muscle
troponin
troponin isomers used in cardiac assay
troponin T, troponin I, troponin C
troponin specimen
plasma (not found in serum of healthy people)
TnI reference range
<0.04 ng/mL
advantages of troponin
- specific
- high diagnostic specificity/sensitivity
- early detection following Myocardial Infarction (MI)
- undetected in healthy people
- remain elevated
- few interfering substances
how to determine re-injury using cardiac markers
cardiac makers remain elevated for a specific period of time, after a few days if levels spike, then it will suggest increase from re-injury
heme protein found in skeletal/cardiac muscle. transports oxygen from muscle cell membrane to mitochondria
myoglobin
clinical use of myoglobin
- early release from damaged muscle
- not specific
myoglobin specimen
serum
myoglobin ref range
<90 ng/mL
POC/ER testing
whole blood analyzer
myoglobin, ck-mb, TnI
12 min
i-STAT
tests for troponin I, followed up on chemistry analyzer upon admission
High Sensitivity C-reactive protein (hsCRP)
acute phase reactant
produced in liver in response to injurt
increase in CRP correlate with CAD and CVD
homocysteine
connection between increased levels and artherosclerosis and formation of blood clots
any structural or functional cardiac disorder that impairs ability of the ventricle to fill with or eject blood
heart failure or congestive heart failure
excessive fluid accumulated in lungs producing edema, reduced output of blood to systemic circulation, retention of fluid by the kidneys
heart failure/congestive heart failure
natriuretic peptide
- hormones that include ANP, BNP
- assist in regulation of cardiovascular homeostasis
- marker of congestive heart failure
- increased renal excretion of sodium
- released on ventricular stretch or stress to myocytes in absence of necrosis
- increased indicated expanded fluid volume (renal failure, CHF)
BNP
BNP specimen
- available on iSTAT
- plasma, EDTA
BNP ref range
<100 pg/mL
rule out infection or anemia
CBC is ordered
fluid imbalance or retention
electrolyte panel
kidney function and damage
BUN/Creatinine
Liver damage
LFT
detect arrhythmias
electrocardiogram
protein in urine, and increased risk of heart failure
urinalysis
high lipids associated with heart disease
lipid panel
hypothyroidism associated with high lipid levels
TSH
embolus lodged in pulmonary arteries, impairing blood flow
pulmonary embolism
markers of pulmonary embolism
chest pain, dizziness, coughing, irregular heartbeat, low PO2, DVT, swelling/leg pain, discoloration, D-DIMER
D-dimer
marker for assessing clot formation/pulmonary embolism
protein produced from breakdown of fibrin clots
d-dimer
a normal D-Dimer rules out
Pulmonary Embolism, deep vein thrombosis
D-dimer specimen
plasma/whole blood
