Monday, July 19, 2021

See many morphologies of non-ischemic ECGs from the same patient

 I was reading ECGs on the system when I saw this one (ECG-1):

What do you think?

My read was "ST Elevation that is NOT ischemic".  

I suspected this strongly because it just doesn't "look right" for a STEMI, in spite of the clear STE in V3 and V4.  This STE appears to be due to LVH, even though the STE in V4 is concordant to the QRS.  

There were previous ECGs for comparison, so I looked at them:

The patient had presented 4 days earlier with chest pain and had several ECGs recorded:

Time zero (ECG-2):

Scary looking STE, but has features of benign STE, especially in V5 and V6: 
Tall R waves, relatively short QT interval, LVH voltage in V2 and V3, pronounced J-wave in V4 and slurring of the J-point in V5, V6.

There were previous ones to compare to at that time:

This is from 13 days prior (ECG-3):

Different, but it certainly suggests that ECG-2 is not ischemic.
This one has more features of standard LVH: high voltage and discordant STE in V2-V4, tall R-waves in V5 and V6.
But concordant STE in V5 is not really typical of LVH

This is from 3 years prior (ECG-4):

Different, but it certainly suggests that ECG-2 is not ischemic
This one has lots of concordant STE in V4-V6.

So serial ECGs were recorded on that presentation 3 days prior:

Time 17 min (ECG-5):

About the same as time zero (ECG-2)

Time 100 min (ECG:-6)

Very similar again

There was a bedside echo.  Here is the parasternal short axis:

This shows severe concentric LVH

Next AM (ECG-7)

Very similar again

On that previous visit, he had been diagnosed with NSTEMI based on hs troponins of 82 ng/L, then 97 ng/L, then 80 ng/L.  But he had always in the past had slightly elevated troponins.  

He did have an abnormal echo:

Normal left ventricular size, severely increased wall thickness. (i.e, LVH)

Moderately reduced systolic function; estimated LVEF 30-35%.

Regional wall motion abnormality-anterior, probable

So chronically elevated troponins are probably due to severe LVH.

But his angiogram was normal (a normal angiogram does NOT rule out ACS or even OMI at the time of the ECG)

On the presentation of ECG-1, he also had elevated trops with a rise and fall (92, 124, 69)

So is this a type 1 MI OMI, type 1 NOMI, or type 2 MI?

My opinion, and also that of the treating cardiologists: the ECG findings are NOT due to any OMI at any time.  They are due to a combination of LVH, benign ST Elevation, and benign T-wave inversion.    

The troponin elevations are due either type 1 Non-OMI or type 2 MI.  

What is certain is this:  all of these ECGs are compatible with a non-ischemic etiology, and you should remember the morphology and suspect that it may be non-ischemic when you see it.

Learning Points:

ECGs are very hard.  They require years of training, paying attention, recognizing patterns.  There are few easy paths to expertise.  

But some takeaways are that, when there is doubt:

1. Look for old ECGs

2. Do serial ECGs

3. Use bedside and formal echo

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