Cardiac enzymes are markers found in the blood that are tested when myocardial infarction (MI) is suspected. The levels of enzymes like troponin I, troponin T, CK-MB, LDH, and myoglobin are normally present but become elevated following damage to the heart muscle. These enzymes are drawn multiple times over several hours as each rises at different times following a heart attack, with troponin I and CK-MB being more specific indicators of an MI compared to troponin T and LDH. Along with considering symptoms, electrocardiogram is also needed to determine if elevated enzyme levels indicate a patient is experiencing an MI.

1. CardiacEnzymes
PROF.MAHENDRALAMBA
SandraShroffROFELcollegeofNursing,
VAPI

2. CardiacEnzymes
Test
 Cardiacenzymesaremarkersfoundin
theblood.
 TheyaretestedwhenMyocardial
Infarction(MI) issuspected.
 Themarkersarenormallypresentatall
times,however,theyaresignificantly
elevatedduringadamageof theheart
muscle.

3. CardiacEnzymes
 IfMyocardialInfarctionissuspected,
enzymemarkersaredrawnseveral
timesusuallysixhours apart.
 Theyarefewdifferentenzymesand
theirlevelsareelevatedhoursafterthe
initialheart damage.

4. CardiacEnzymes



Troponin:–contractileprotein,twotypes:
TroponinTfoundinthecardiacandskeletal
muscle,elevatedduringkidneyandskeletal
muscledamage,earlyriseafter3-4 hours,
peakis24hours.
TroponinIfoundonlyincardiacmuscle,more
specificbutriseslater,4-6hours,peakisat 18
hours.

5. CardiacEnzymes
CreatinePhosphokinase(CK-MB): is
highlyspecifictestforMI,elevationof
4%andhigherindicateMI.
 Thetimetoriseis4-6 hours,timeto
peakis24hours.

6. CardiacEnzymes
Lacticdehydrogenase(LDH): thereis
LDH1andLDH2, normallyLDH2is
greaterthanLDH1, if LDH1isgreater
thanLDH2thanthepersonispositive
for MI.
 Howeverincreaseinleveloccurs48to
72hrsaftertheonsetofsymptoms.

7. CardiacEnzymes
 Myoglobin:isamuscleproteinwithhigh
sensitivity, butlowspecificity(canbe
elevatedduringothermuscleinjuries).
 Timetoriseis1-4hours
 Peaktime6-12hours

8. CardiacEnzymes

9. CardiacEnzymes
 Thegraphrepresenttheelevationof
thedifferentcardiacenzymesduring
MyocardialInfarctioninthehoursafter
theinjury.However,Electrocardiogram
is also necessary alongwith
considerationofthesignsand
symptomsduringtheMIinorderto
determentifthepatientishavingaMI.