the most sensitive test for myocardial infarction is
1 Serum levels increase within 3-12 hours from the onset of chest pain, peak at 24-48 hours, and return to baseline over 5-14 days. 2  Troponin levels may not be detectable for six hours after the onset of myocardial cell injury. 3  The most sensitive early marker for myocardial infarction is myoglobin.