D. CK-MB – Explanation
By day four the CK-MB levels should have returned to normal from the initial myocardial infarction. If
the CK-MB levels are elevated it would indicate a further coronary event
Cardiac enzymes and protein markers
Interpretation of the various cardiac enzymes has now largely been superceded by the introduction
of troponin T and I. Questions still however commonly appear in the MRCP
Key points for the exam جدا مهم
- myoglobin is the first to rise
- CK-MB is useful to look for reinfarction as it returns to normal after 2-3 days (troponin T remains
elevated for up to 10 days)
| Begins to rise | Peak value | Returns to normal | |
| Myoglobin | 1-2 hours | 6-8 hours | 1-2 days |
| CK-MB | 2-6 hours | 16-20 hours | 2-3 days |
| CK | 4-8 hours | 16-24 hours | 3-4 days |
| Trop T | 4-6 hours | 12-24 hours | 7-10 days |
| AST | 12-24 hours | 36-48 hours | 3-4 days |
| LDH | 24-48 hours | 72 hours | 8-10 days |
