Sunday, October 12, 2014

Some Cardiologists still are not familiar with Sgarbossa Criteria.....

This case shows how you have to advocate for your patient. You have to be the expert.  I talk to a lot of emergency physicians who have trouble convincing their interventionalist colleagues of various ECG findings.  

Many cardiologists and even interventionalists, are not aware of many of the newer findings of STEMI equivalent, including the Sgarbossa criteria, and especially are unaware of the modified Sgarbossa criteria.  

My partners and I are fortunate that at our institution there is a long history of ECG expertise in our cardiology department.  We also have a very cooperative system in which all concerns of the emergency physicians are addressed.

It is very important to establish these relationships so that when difficult cases arise, the patient gets the best care.

Case presentation

A male in his mid 40's presented with 20 minutes of chest pain.  He had no previous cardiac disease.  Here is his first ECG:
There is sinus rhythm with LBBB.  There is subtle concordant STE in lead aVF, almost 1 mm.  There are about 2 mm of discordant STE in III.  Since the S-wave is only 3 mm, this is proportionally excessively discordant ST elevation.

One may not be convinced of STEMI with less than 1 mm of concordant STE and 2 mm of discordant STE, but it should certainly catch your attention.

Within minutes, the patient had a ventricular fibrillation arrest and was resuscitated.  This is the post-resusitation ECG:

There is sinus tach and LBBB still.  Now there is huge concordant ST elevation in III, also in aVF, and huge reciprocal concordant ST depression in aVL.  There is concordant STE in V3 and excessively proportionally discordant ST depression (greater than 30% ratio) in V5 and V6.


This second ECG is diagnostic of STEMI.

The physician activated the cath lab in the middle of the night.

When the interventionalist heard that the patient had LBBB, he was furious and stated that you cannot diagnose STEMI in the presence of LBBB (even though there was a cardiac arrest).

When he arrived and saw the ECG, he insisted that all ECG findings were due to post-resuscitation changes.  (Aside: while it is true that cardiac arrest can cause strange ST elevation, one can easily differentiate it from actual coronary occlusion by obtaining serial ECGs.  If due to cardiac arrest only, it should quickly start to normalize).  

He insisted that "You inappropriately called in the cath team.  The only STEMI by criteria is 2mm ST elevation in 2 consecutive leads with normal QRS AND it is the cardiac arrest that created these ECG abnormalities." 

The emergency physician insisted that it was STEMI and instructed on the Sgarbossa criteria.  

He did take the patient to the cath lab and found a 100% acute RCA occlusion.

He still insisted that there are no ECG findings in of STEMI in patients with LBBB except for New LBBB.

She gave him some papers to read.  We now know that new LBBB has very weak correlation with acute occlusion, and that + Sgarbossa criteria is very specific for occlusion, and that the modified Sgarbossa criteria are much more sensitive.

Here is a calculator from mdcalc.com: http://www.mdcalc.com/sgarbossa-criteria-for-mi-in-left-bundle-branch-block/

Learning point: You need to be the ECG expert and advocate for your patient
The emergency physician's confidence in her diagnosis could have been undermined by the interventionalist.  She could have doubted herself and relented.  But she had learned about LBBB and Sgarbossa criteria well enough to be confident.  She also was aware that consultants are fallible, and have various occasional weaknesses.  So she was able to be persistent in advocating for the patient, and to do so diplomatically, so that the interventionalist would not resist.


Imagine how resistant the interventionalist would have been if the patient had no cardiac arrest, but rather chest pain only.



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