Tachycardia, Dehydration, and New ST Elevation in a 20-something, then a Surprise.

A male in his early 20s presented intoxicated, with no CP or SOB.  An ECG was obtained for tachycardia.

First ECG:

Sinus tachycardia at 150.
There is inferior ST Elevation and Q-waves that appear to be Inferior STEMI.
There is reciprocal ST depression in aVL.
Is this STEMI?

The patient was very dehydrated.

The physicians were worried about STEMI, and so did a Point of Care Cardiac Ultrasound which showed IVC collapse and hyperdynamic function.

The patient had a previous visit with dehydration

There had been some, but less, STE
Not very similar to this one.

There was another previous visit with dehydration

Also not similar

He was given 2 liters of IV fluids.  A 2nd ECG was recorded 1 hour later:

Sinus tach at a rate of 120
Heart rate and ST segments are almost normalized 
What do you see now?
See below.

Unexpectedly, there is every other beat pre-excitation.  So the patient has WPW. This was never diagnosed before.  But I don’t think this explains his ST segments.

Clinical course

3 serial troponins were below the 99% level of 0.030 ng/mL, but not undetectable.

K was 4.5 mEq/L.

The patient was rehydrated and discharged.


Why the PseudoSTEMI pattern?

I don’t know for certain, and this ECG sure looks like inferior STEMI.  However, patients with STEMI generally do not have tachycardia unless they are in cardiogenic shock.  If such is the case, the patient should have high filling pressures and high right sided pressures and NOT have a collapsed IVC.  They should also not be hyperdynamic.

It is possible to be dehydrated AND have a STEMI, but in that case the best initial treatment is supportive: rehydration.  Then re-evaluation.

So it was perfectly appropriate to do a bedside ultrasound and, finding a hyperdynamic heart, to defer diagnosis of ACS and give fluids.  Even if this STE is due to ischemia, it is most likely due to demand ischemia, NOT due to ACS, and the best initial therapy is to hydrate.  In our many studies of type 2 MI, we found that 2-5% had ST elevation on the ECG.

Final comment:

I sent this to Ken Grauer, who is a fantastic ECG resource and has much experience with stress ECGs, and asked if this is a pattern he has seen in stress tests.  He stated “no,” (in a few more words than that).

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