7 day old MI the most sensitive biochemical marker
TnI and TnT normally are not found in the circulation; however, after acute MI, both are detectable within 2 to 4 hours, with levels peaking at 48 hours and remaining elevated for 7 to 10 days. Although cardiac troponin and CK-MB are equally sensitive markers of the early stages of an MI, persistence of elevated troponin levels for approximately 10 days allows the diagnosis of an acute MI long after CK-MB levels have returned to normal. With reperfusion, both troponin and CK-MB levels may peak earlier owing to more rapid washout of the enzyme from the necrotic tissue. (Robbins basic pathology,9th edition,pg no.383)
Troponin T
CPK MB
LDH
Myoglobin
Cardiovascular system