ASCP Medical Laboratory Technician (MLT) Practice Exam

The correct choice identifies CK-MB and myoglobin as two biomarkers that are not specific to cardiac muscle and can be elevated in the context of injury to other muscles.

CK-MB, or creatine kinase-MB, is an isoenzyme found in the heart but can also be present in skeletal muscle. When muscle damage occurs, such as in rhabdomyolysis or severe muscle trauma, CK-MB can be released into the bloodstream, leading to elevated levels that do not exclusively indicate cardiac injury.

Myoglobin is a protein found in both cardiac and skeletal muscle, primarily functioning to store and transport oxygen within muscle tissues. Similar to CK-MB, myoglobin can be elevated in cases of muscle injury or necrosis, such as with extensive trauma or other skeletal muscle disorders. This non-specific elevation makes myoglobin a useful marker for assessing muscle injury in general, but it does not uniquely indicate cardiac muscle damage.

Both of these biomarkers provide valuable information in clinical settings; however, their lack of specificity means that elevated levels may not reliably distinguish between cardiac and non-cardiac muscle damage. Understanding their roles helps healthcare professionals interpret laboratory results more effectively, especially when diagnosing conditions related to muscle injury.