Question

which of the following is the first to be elevated in the bloodstream following occlusion of a coronary artery and infarction of myocardial tissue?
troponin
ast
ldh
cpk - mb fraction

Explanation:

Troponin is released into the bloodstream within 3 - 4 hours after myocardial infarction. AST (Aspartate aminotransferase) elevation occurs 6 - 12 hours after infarction. LDH (Lactate dehydrogenase) elevation is seen 8 - 12 hours after infarction. CPK - MB (Creatine phosphokinase - myocardial band) fraction elevation occurs 4 - 6 hours after infarction. Since we are looking for the first biomarker to be elevated, we compare the time of elevation of each biomarker.

Answer:

Troponin