Description
Cardiac Troponin I is aprotein found in cardiacmusclewithamolecular weight of 22.5kDa. Troponin I ispartof a threesubunit complex comprisingof TroponinTandTroponinC.Alongwithtropomyosin, thisstructural complexforms themain component that regulates the calcium sensitive ATPase activity of actomyosin in striated skeletal and cardiacmuscle. After cardiac injury occurs, TroponinI isreleasedintotheblood4-6hoursaftertheonsetofpain.Therelease patternof issimilartoCK-MB,butwhileCK-MBlevelsreturntonormalafter72 hours,TroponinIremainelevatedfor6-10days,thusprovidingforalongerwindow ofdetection for cardiac injury. Thehighspecificityof cTnImeasurements for the identificationofmyocardial damagehasbeendemonstrated inconditions suchas theperioperativeperiod,aftermarathonruns,andbluntchesttrauma release has also been documented in cardiac conditions other than acutemyocardial infarction (AMI) such as unstable angina, congestiveheart failure, and ischemic damageduetocoronaryarterybypasssurgery.Becauseof itshighspecificityand sensitivity in themyocardial tissue, Troponin I has recently become themost preferredbiomarkerformyocardial infarction.
