MI & Liver Enzymes

Remember - does the investigation rule out/in? Dx

MI Enzymes

CK
- rises 3-6hrs after event
- only 50% pts show rise > ULofN @ 4hrs
- CK rises by over 50% over 12 hrs

CK-MB
- rises earlier than CK
- 3% CK-MB in skeletal muscle
- rhabdomyolysis = raised absolute levels
- better test = CK-MB/CK

+
Sys + ECG
CK-MB to confirm CK

Troponin

Myofibrillar protein fr damaged cells
- subtypes inc trop-T/trop-I
Measured at 12hrs post onset
Elevation persistent up to 10 days
Can indicate low-grade myocardial damage before infarction, requiring acute treatment
Good specificity

Liver Enzymes

ALT - cytosolic enzyme

ALP - biliary brush border enzyme
GGT - ribosomal test, x liver specificity