Friday, April 2, 2021

Prehospital Cath Lab Activation for inferior STEMI -- do you agree?

A 40-something male complained of 3 days of chest pressure.  He called 911.  He had some pulmonary edema and hypoxia.

Here is the prehospital ECG:

The computer says ***STEMI***
Based on this and the presence of chest pain, the medics did a prehospital activation of the cath lab.
What do you think?

Interpretation: There is clear atrial flutter. Look at the spikes in V1 at a rate over 300, which are flutter waves.  The flutter wave in the inferior leads mimics ST Elevation.  

An ED ECG was recorded:

Confirmed Atrial Flutter
Again, notice the flutter waves manifest are sharp spikes in V1
There is 2:1 conduction.
The atrial rate is over 300, with a ventricular response at a bit over 150

The cath lab activation was cancelled and the patient was electrically cardioverted.

Here is the post cardioversion ECG:

Sinus tachycardia
Look at the P-waves
Notice the very large upright AND inverted portions of the P-wave in lead V1.  
Notice also the large P-wave in lead II.  
These features indicate right and left atrial enlargement and explain the pronounced size of the atrial flutter spike in V1 during flutter.


  1. I think the medics were following the protocol set forth by their medical director.

    1. They followed the protocol. But with some more ECG education, they might have been BETTER than the protocol.


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