Cardiac enzymes

Markers

Name INTL ELV PEAK RETRN myglbn 1-4h 6-7h 18-24h trp I 3-12 10-24 3-10d trp T 3-12 10-24 5-14d ckmb 4-12 12-24 48-72 ldh 8-12 24-48 10-14d

n I - 2-4 hrs 1st detect

          8-12 hrs w/100% sensitivity

          10-24 peak

          5-10 day duration

Tn T - above plus 5-14 d duration

CK-MB : 3-4

                 8-12 (100% sensitive)

                10-24 hr peak

MYOGLOBIN : 1-2 hrs detect first

                            4-8 100% sens

                             4-8 peak

                             0.5-1.0 duration

                 2-4 day duration

Creatine Phosphokinase

-can be elevated in trauma, rhabdo, hyperthermia, physical activity, renal or endocrine dz, systemic infections

-if pt small with small muscle mass to begin with, total ck may not be elevated- so better to use ck index- is ratio of ckmb/ total ck. Elevated if > 3- 5%.

-CK Mass: with monoclonal antibody techniques, can directly measure ck mb mass as mmcg/L. More sensitive for detection of ami

Troponins

-during contraction of muscle- thick filaments of myosin slide past thin filaments of actin by calcium mediated atp dependent contraction. Released calcium binds to troponin C, T, and I, which regulate muscle contraction.

-troponins not change in trauma, skeletal muscle dz, exercise, renal failure like ck does.

-troponin C found in all tissue and is not cardiac marker

-troponin T is qualitative assay.

-troponin I is quantitative assay.

See Also

Cards: CK-MB

Cards: Troponin