Jerome also had blood work done to confirm the MI. The presence of troponin, or cardiac enzymes such as CK-MB, are a positive indicator of an MI. Why is their presence at higher levels in the blood indicative of an MI?

a. They are by-products of aerobic metabolism and if they are present in higher amounts in the blood it shows that the myocardium is working harder.

b. They are substrates for aerobic metabolism and if increased in the blood show that the cardiac muscle is not functioning normally.

c. These proteins are normally found inside cardiac muscle cells and if present in the blood indicate damage to the cells.

d. They are by-products of anaerobic metabolism (glycolysis) and if increased indicate that the heart is not receiving oxygen.

c. These proteins are normally found inside cardiac muscle cells and if present in the blood indicate damage to the cells.

Explanation:

When there is a decreased blood flow to the heart or if a particular part of the heart stops working then this is known as myocardial infarction (MI) and due to this the heart muscle gets damaged. There are several biomarkers that are used to evaluate the functioning of the heart and these are known as cardiac markers, an example of this is Ck-MB which is an isoform of creatine kinase. The CK-MB isoform is found in the cytosol of the heart muscle cells and it plays a role in causing the movement of high energy phosphates in and out of the mitochondria. If there is a damage to the heart muscle cells which usually occurs following a myocardial infarction CK-MB levels elevates in the blood for a short period of time and this indicates MI.