Cardiac injury markers Flashcards
Acute coronary syndrome
1) Unstable Angina
2) STEMI
3) NSTEMI
Unstable Angina has to meet 1 of the following criteria:
1) Occurs at rest and lasts 10-20 min
2) New onset and severe (w/in past 4-6 weeks)
3) Crescedo pattern (worse, longer, more freq)
Creatine Kinase is not specific but
myocardial fraction of CK is specific (CK-MB)
More sensitive and specific cardiac enz
Troponin
Chest pain with:
No ECG changes
Normal CK-MB
Elevated troponins
Indicate MI
Criteria for MI:
Typical rise and fall of biochemical markers of myocardial necrosis and at least 1 of the following:
- Ischemic sx
- New pathologic Q waves
- ECG changes like ST elevation or depression
- Imaging evidence
Ischemic sx suggestive of ACS but w/ no elevateion of CK-MB or troponins or w/o ischemic ECG evidence
Unstable Angina
If troponins and/or CK-MB elevated
Pt assumed to have had MI
Regulatory proteins that control the calcium mediated interaction of actin and myosin
-Preferred marker for dx of MI
Troponins
Decrease to normal in 5-14 days
Detect microinfarcts
Troponins
Cardiac surgery Myocarditis Trauma Cardiac cath Shock
Other causes of elevated CK-MB
Decrease to normal in 36-48 hours
CK-MB
Cardiac enzymes ordered q
6 hours x 3
95% sensitivity and specificity for MI when measured w/in 24-36 hours of onset of pain
CK-MB
Rise 3-4 hours
Peak 10-24 hours
Troponin
Rise 3-6 hours
Peak 18-24 hours
CK-MB
Preferred initial approach to tx of STEMI
after MONA of course
Primary percutaneous coronary intervention (PCI)
safer than thrombolysis, improved perfusion so if pt can be cathed, avoid fibrinolysis
Tx of unstable angina and NSTEMI
MONA
Anticoag
Beta blocker
Consult cardiologist
DO NOT USE FIBRINOLYSIS
Detect necrosis that has already occurred
Serum enzymes
-Normal enz don’t r/o current ischemia or recent infarct w/in previous few hours
STEMI tx summary
PCI or fibrinolysis
Aspirin (MONA)
Cardiology consult
Important for all 3 (STEMI, unstable angina, NSTEMI)
Aspirin
