# STEMI Mimickers in Your System



## Fox800 (Apr 7, 2012)

Hi all. My system's STEMI guidelines have become a lot more restrictive in the past few years due to a high number of false activations. I'm curious to see if there are any mimickers in your system that negate a STEMI alert.

In my system, we cannot declare a STEMI alert if the following are present:
-LVH (categorized as V1 + V5 or V6 > 35mm)
-LBBB
-Isolated elevation in V1/V2
-Early repolarization
-Ventricular/Ventricular paced rhythm
-Diffuse ST elevation


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## Arovetli (Apr 7, 2012)

Telemetry data to ED physician for analysis. If the hospitals can spend the money on STEMI alerts/cath labs they can spend the money on ensuring telemetry transmission. Decision should rest with a physician. (probably an unpopular opinion to some)


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## DrankTheKoolaid (Apr 7, 2012)

With the LBBB inclusion do you look for concordant ST elevation before completely disregarding it such as Sgarbossa criteria?


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## Fox800 (Apr 7, 2012)

Corky said:


> With the LBBB inclusion do you look for concordant ST elevation before completely disregarding it such as Sgarbossa criteria?



We completely disregard it. If the patient is symptomatic but has the mimickers mentioned above, we fax the 12-lead to the receiving ER physician and consult with them. They decide whether to activate the cath lab if a mimicker is present.


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## DrankTheKoolaid (Apr 7, 2012)

Gotcha, im sure they are looking at it then


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## NYMedic828 (Apr 7, 2012)

in NYC all STEMI activations must go through the telemetry physician. We cannot directly activate the cath lab. We can only activate trauma/code/stroke.


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## TomB (Apr 8, 2012)

If you're suggesting that in all other circumstances you can activate without transmission that's actually pretty cool and probably a best practice! I would take issue with "early repolarization" being on the list because differentiating between BER and LAD occlusion is extremely difficult. There are some "tricks" like looking at R-wave progression (and more complex criteria) but who could be blamed for activating with an ECG like this?

http://hqmeded-ecg.blogspot.com/2012/03/anterior-st-elevation-with-large-broad.html

False activations are going to occur. Period. End of story! ED physicians are not the gods of ECG interpretation either. However, they are far less likely to activate based on simple LBBB, simple paced rhythm, wandering baseline or other poor data quality, and so on. Pericarditis can be very difficult (as a recent case posted here illustrates). Bottom line is that a homerun STEMI can easily be identified by paramedics and they should be able to activate when they see one. For more difficult cases in a system where false positives are a problem I believe that each case should be fed back to the paramedics as continuing education (which should make the system stronger and stronger) but in the meantime nothing wrong with another set of eyes on the ECG!

Awesome topic and I'm always interested in hearing how this issue is being handled around the country and around the world! This is one of the most frequent things I'm asked about by EMS systems interested in improving their STEMI systems.

Tom


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## NYMedic828 (Apr 8, 2012)

The ball and chain cut me off before when I was typing my first response.

Furthermore in NYC, if the monitor itself regardless of technician interpretation reads >>>ACUTE MI<<< we MUST transmit the ECG to telemetry for further evaluation.

This can be pretty irritating sometimes but overall the machine is pretty accurate. (Phillips MRX)

We also must transmit NEW onset LBBBs.

We must transmit any contiguous elevations of two or more leads with ST elevations of 1mm or more.


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## KellyBracket (Apr 9, 2012)

A new paper, just in press, provides a fairly simple 4-step method for sorting out the STEMI "wheat" from the mimic "chaff:"
The use of a 4-step algorithm in the electrocardiographic diagnosis of ST-segment elevation myocardial infarction by novice interpreters.

The full paper is by subscription, but you can read a review here.

Prehospital ECG interpretation and activation can be a vexing topic. Every system has  their own way of dealing with it. A good (free!) review was written by the American Heart Association, and details the pros and cons of various systems.


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## TYMEDIC (Apr 22, 2012)

In our system, impostor s are lbbb, BER, LVH, ventricular origin rhythms


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## Brandon O (Apr 28, 2012)

Fox800 said:


> Hi all. My system's STEMI guidelines have become a lot more restrictive in the past few years due to a high number of false activations. I'm curious to see if there are any mimickers in your system that negate a STEMI alert.
> 
> In my system, we cannot declare a STEMI alert if the following are present:
> -LVH (categorized as V1 + V5 or V6 > 35mm)
> ...



Thank goodness nobody with one of these baseline conditions would ever have a STEMI, nor would a STEMI ever cause one of them to be present. (Even though the AHA's _stated_ reason for treating LBBB as a STEMI is specifically because mortality is very high when one causes the other.)

I get the point, but these sort of flat prohibitions rub me the wrong way a little. The patients falling through the cracks are some of the sickest ones.


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## ZootownMedic (May 13, 2012)

We use the Sgarbossa criteria here. It is up to the individual medic to call a STEMI and get the ball rolling for cath lab activation. Door to balloon time of <90 minutes often depends one early recognition, regardless of mimickers. Obviously many paramedics hands are tied by certain protocols in some areas which sucks.


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