Question about CKMBs and Troponins

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Specializes in Med-Surg.

I'm a new grad with a R/O MI who has elevated CKMBs on the first three serial draws and normal Troponins. Can you help me understand the relevance of this? Because troponins are neg the view is that he's neg for MI, but my limited education tells me that CKMBs are heart muscle related... I know they're not as specific as troponins, but the pt hasn't had heart surgery or any blunt trauma. What else raises these levels? Pt also has a hx of HTN and Diab type I.

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Specializes in Telemetry & Obs.

http://www.labtestsonline.org/understanding/analytes/ckmb/test.html

"Sometimes persons who are having trouble breathing have to use their chest muscles. Chest muscles have more CK-MB than other muscles, which would raise the amount of CK-MB in the blood.

Persons whose kidneys have failed can also have high CK-MB levels without having had a heart attack. Rarely, chronic muscle disease, low thyroid hormone levels, and alcohol abuse can increase CK-MB, producing changes similar to those seen in a heart attack."

Don't know if this helps...

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Has this patient had any im injections? We were told at lecture that if a patient is suspected or having MI ruled out that no im injections are given because that is actually entering the muscle which would cause enzymes to be detected, & due to the heart also being a muscle that it could cause a false + result on any tests that detect enzymes for muscle damage such as in MI's.......

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Specializes in ICU, Education.

The index is the important factor regarding the CKs. TWhat percentage of the total CPK consists of CKMB? Am I saying that clearly?

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Specializes in Telemetry.

Thank you TRUERN - that website is awesome. I've been struggling with the lab results of some of my patients. -steu

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Specializes in Cardiology.

In addition to IM injections and renal problems, you have to consider what else might have happened to the patient within the last few days. Any falls? Unusual exertion (like moving furniture or something)? CPR? Car accident? Anything that causes muscle damage can cause the muscle cells to release the CK enzymes. Those are not specific to cardiac muscle. Troponin IS specific to cardiac muscle tissue. Our cardiologists put much more stock in what the patient's troponins are than what the CKMBs are, and don't hardly consider total CKs. I do ACC database collection, and they don't even ask for the total CKs, just the MBs and troponin I.

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