[ecgram]

An unrestrained driver sustains a blunt chest injury in an automobile accident, and is taken to the emergency room. The emergency room physician wants to determine if the heart was bruised when he collided with the steering wheel. The levels of which of the following creatine kinase isoenzymes or combination of creatine kinase isoenzymes would be most useful for this determination?
A. BB isoenzyme
B. MB isoenzyme of creatine kinase
C. MM isoenzyme of creatine kinase
D. Total creatine kinase and the MB isoenzyme
E. Total creatine kinase and the MM isoenzyme

 

[drmodi44]

B??

B....MB isoenzyme of creatine kinase

 

[ecgram]

D is the answer
B is correct but most appropriate is D

The MB isoenzyme of creatine kinase is associated with heart damage; the MM
isoenzyme is associated with muscle damage; and the BB isoenzyme is associated with brain damage. Actually,
most tissues contain a mix of creatine kinase isoenzymes, but one species often predominates. In the case of
myocardial infarction not occurring in the setting of trauma, either total creatine kinase, or, preferentially, the
MB isoenzyme can be used for monitoring. However, in a complex setting such as in this case, where there is
known skeletal muscle damage secondary to trauma, the ratio of the MB isoenzyme to total creatine kinase is
most informative.