So, here is the ECG again :
If you need to see the patient presentation, then click here to read part one of this post.
I said that as well as the ECG itself, I wanted to have a bit of a discussion about something that cropped up and made me think a little after the job. But first, the ECG.
Some of you got this as the same interpretation as me. Some of you went into more depth than I know (especially Tom Bouthillet who sent an email to me) and some of you were a little off, but I can only share with you my thoughts about the ECG.
Bearing in mind that the patient was asymptomatic, young and a fit gentleman, I got a bit of a shock when I saw this come out of the Lifepak 12 with an interpretation of “Extensive Myocardial Infarction” on it. I glanced at the patient again, then took a few seconds to really look at the ECG, then come to my interpretation.
I thought this was an STEMI Mimic/imposter and not ‘real’ ST Elevation. The patient has huge QRS complexes especially notable in V1, V2, V3 and V4. The ST Elevation that can clearly be seen in V1, V2 and V3 is what I interpreted as what is commonly referred to as ‘high takeoff’ or Benign Early repolarisation, but he also displayed some characteristics of LVH (left ventricular hypertrophy). All QRS complexes are within normal widths but the depth of the S waves in V1, V2, and V3 make it very difficult to discern between the S waves and the R waves of the lead below. If you take the time and really look, you can figure out where the S wave ends in V1 and V2 and it can be seen that the corresponding height of the ST Elevation increases with the increasing depth of the S wave. This is a finding which is not seen in Acute AMI and helps to make a determination that this is not a STEMI. Take all of these findings along with the fact that there are no reciprocal changes anywhere else on the ECG, and things start to slip into place.
My fellow blogger, Tom Bouthillet has also wrote about the shape/morphology of the ST Segment and what characteristics the ST Segment has for Acute AMI compared to the STEMI Mimics. This tracing shows an upwardly concave ST segment as opposed to an upwardly convex segment.
Take these two diagrams reproduced from Tom’s blog, Prehospital 12 Lead ECG.
Tom goes on to write:
“This finding is not particularly sensitive. It is, however, fairly specific……….The STE-mimics almost always present with upwardly concave ST segments and an absence of reciprocal changes”
But, taking all of this into account, what gave me the biggest sense of security is that it ‘just didn’t look like an MI’ on the 12 Lead ECG.
Maybe this comes with practice and extended self learning, but after a time, you just get a ‘feel’ for ECGs, even if you can’t definitely diagnose everything that you think you can see on the ECG.
This brings me to the main point of this post.
I had a patient in the back of my ambulance who I was sure, after a full assessment, was not having an MI, yet his ECG stated that he was. Everything that I had learned in my own time about STEMI mimics and imposters is not taught in my service and is seen well above the level that is required for an operational paramedic. I was confident to just take this patient to the local Accident and Emergency department rather than transmitting the ECG to the regional PPCI (Primary Percutaneous Coronary Intervention or Angioplasty) centre, however, I was stepping WAY outside of my current guidelines by doing this.
What if I didn’t take him to a PPCI centre and this did turn out to be an MI? I would be hung out to dry!!
If I ended up in a ‘clinical variance committee’ meeting and I was judged by my peers, It would be highly likely that those who were giving their opinions would not know what I do about 12 Lead ECG interpretation, and all they would see was that there was ST Elevation and the LifePak 12`s Interpretation said Extensive Myocardial Infarction.
So, I did what I had to do, and transmitted the ECG to the PPCI Centre. When I spoke to them on the vehicle mobile phone I gave them my assessment and my interpretation of the ECG. The Nurse in charge went off to speak to the consultant then came back to the phone and stated that the consultant agreed with my interpretation and that I had to take the patient to the local A&E Department.
Which begs the question, why do I need to know so much more about 12 Lead ECG than what I teach others in the Paramedic training course our service runs?
I can definitely see the benefit in more education on detecting the more subtle findings of ‘borderline’ MI recognition and I have, on more than a few occasions, referred patients to PPCI who did not initially meet criteria for referral, but whose angiograms had gone on to show a blockage of a coronary artery. I guess you will never get fired for referring someone who wasn’t actually having an MI?
However, deciding that someone isn’t having an MI, even though their ECG makes it look like they are (to the untrained eye), and not referring them or transporting them, is a whole other ball game.
I am confident with my interpretation abilities, and I have yet to be caught out (even though I know it is only a matter of time), but I will still continue to transmit the ECGs to the PPCI centres for someone more senior and on a whole lot more pay than I get, to make the final decision on transport and treatment of ?STEMI Mimics.
Does that mean that I don’t need the level of knowledge that I have?
Maybe…..But I am an ECG Geek and I just always want to know more and more?
What are your thoughts?
Would you ever decide to not transport or refer someone who ‘by the book’ meets criteria even though you know it is a STEMI Mimic?