Posterior Lead Placement

Difficult to find diagrams of posterior lead placement. But this a good example of v7- v9

Troponin is a very sensitive marker for cardiac damage. For true readings this should only be undertaken 12 hours after pain has started. You can get false reading prior so will only have to repeat.

The range we use is as follows:

<0.10  low risk

0.1—0.6 intermediate risk

0.6 High risk. 

However, these are the lower end, as you will read in some of the case histories, 150 can be reached with a full MI.

Creatine Kinase

Creatine Kinase (CK) is an enzyme which is measured to identify how much damage has occurred following an MI.  

Normal range is 0-200. It is not uncommon for an average CK rise

to be 2000-3000, even rising up to 10,000. 

Can you have a raised CK and not have damage to your heart?  

Yes you can, CK is not exclusive to heart muscle, it is also present in all other muscle. I once had a young patient who had been water skiing, who’s CK was >5000, this was due to muscle trauma, the patient having fallen in the water at speed—several times!!

The initial concern was that this was due to a cardiac event, which nearly caused her to have one in the process!! Taking a good history is important in these circumstances.

Bundle Branch Block BBB

The Quick guide to “is it RBBB or LBBB”

The world of William Marrow. See diagram. So for a RBBB you should have a QRS complex of greater than  0.12ms or 3 small squares, and a RSR pattern in V1 or “M” with a “W” in V6.

If you now look at Case 26’s ECG you can see a “M” formation- more clear in V1, not so clear is the “W” V6, giving a RBBB. Don't worry if you are not able to always clearly see both V1 and V6  

As you can see from the diagram opposite, because the conduction system has been damaged, the left and right chambers can no longer depolarize together, this causes, the two chambers to contract fractionally out of phase. Giving this unusual morphology to the QRS complex