Which is the reinfarction cardiac marker?
It's CK MB. The levels fall in 3-4 days. So if you get a reinfarction and see your troponin you can't be sure if it's from last time.
CK MB falls in 36-48 hrs.
Why isn't it myoglobin? Myoglobin rises and falls the fastest.
Because myoglobin is not a specific cardiac marker.
No but in these cases, it is the most preferred. Cause it returns to normal within 24 hours.
I think the time after which re-infarction occurs also matters.
Do let us know.
These things are confusing. Good thing is we are trying to sort them out.
Yes, it is.
We had a confusion between myoglobin and CK MB in the diagnosis of re-infarction.
The answer is CK MB simply because it is cardiac specific and falls within 2 days.
The only use for myoglobin is ruling out a Myocardial Infarction, early. (Cause it's the first to rise and is very sensitive!)
If the levels are not up, it's not a MI.
If myoglobin levels are up - it could be a skeletal muscle injury or a MI, you don't know until you look at the other markers.
Even though myoglobin levels fall early, it is not used for the diagnosis of reinfarction because it's not specific and if the levels are up after an infarction, it could mean something else as well.
Harrison says both CK MB and myoglobin can be used for reinfarction. I would hate the question maker for asking us to choose between the two & go with CK MB because it's specific.
Woah... Awesome discussion... Thank you everyone for the cocepts... I so love this group.