Wednesday, January 25, 2017

A Patient with Cocaine Chest Pain and Prehospital Computer interpretation of ***STEMI***

A 20-something male drank heavily of ethanol and used cocaine, then was involved in a stressful verbal altercation, at which time he developed chest pain.

911 was called and the medics recorded this ECG (unfortunately, leads V4-V6 are missing)
Due to marked ST Elevation, the computer read was ***STEMI***
What do you think?

He arrived in the ED and had this ECG recorded:
Very similar to the prehospital ECG.
The Mortara (Veritas algorithm) Interpretation was:

 ***ACUTE MI***
What do you think?

The ECG shows Brugada morphology in V1 and V2, and the typical normal variant ST elevation in lead V3.

Brugada morphology can be caused by baseline Brugada morphology, including Brugada syndrome, or by hyperkalemia or Sodium channel blockade.

Cocaine not only has effects on dopamine neurotransmission, but is also a sodium channel blocker, as are all "-caine" local anesthetics.  Cocaine is well known to result in Brugada morphology.

See this post and associated case reports:

Cardiac arrest, severe acidosis, and a bizarre ECG

The patient was admitted and ruled out for acute MI by serial troponins.

Below are subsequent ECGs, showing resolution of the Brugada morphology as the cocaine metabolizes.  Cocaine metabolism is rapid.  After approximately 3-4 hours, the cocaine and its effect are gone.  Testing for cocaine is for the inactive metabolite Benzoylecgonine, and this inactive metabolite is present for days.  So a positive screening test for "cocaine" does not imply persistent intoxication.

Here are the serial ECGs:
Time 1 hour:
Cocaine Brugada Effect is still present

Time 4 hours:
Minimal effect is still present

Time 10 hours:
The ECG only shows some slight abnormalities in V1 and V2, with minimal residual saddleback morphology in lead V2.

The vast majority of cocaine chest pain is NOT due to myocardial ischemia or infarction, and most is in young males with normal variant ST Elevation or LVH, so it often looks scary on the ECG.

As there was no personal history of syncope or family history of sudden death, the patient was discharged with cardiology followup.

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