Cardiac Biomarkers
- Normal Range:
- 15-100 U/L males
- 10-80 U/L females
- In MI,
- Rises within 3-6 hrs of infarction- early detection
- Isoenzymes – CK is a dimer with subunits M and B
- MM – seen in muscles – 80% seen in blood
- MB – heart – 5% seen in blood
- BB – brain – 1% in blood
- Estimation of MB-isoenzyme is the best diagnostic marker in MI.
- Total CK increased in serum in muscular dystrophy.
- Troponin complex has 3 components
- Tn C (Ca2+ binding )
- Tn I (actomyosin ATPase inhibitory)
- Tn T ( tropomyosin binding).
- Troponin I
- Released within 4 hours
- Peaks at 14-24 hours ,remains elevated for 3-5 days
- Marker at any time interval after attack
- Troponin T
- Increases within 6 hours
- Peaks at 72 hrs , remains elevated for 7–14 days.
- Present in brain and heart (more in heart)
- Family of natriuretic peptides – ANP,BNP,CNP.
- ANP- atrial
- BNP- released from ventricles on excessive stretching.
- Congestive heart failure – high ANP & BNP seen.
Textbook of Biochemistry for Medical Students, DM Vasudevan, 6th Edition, pg266