To STEMI or not to STEMI, that is the question...

[Fish]

I am well aware of some of the conditions that can mimic elevation. However, I'm not sure that it is good practice for me to pick and choose which ST elevations I treat as a confirmed STEMI and which I do not, with the exception of clear cut issues, such as a LBBB. It is, however, good information to keep in the back of your mind.

I agree with you on the contiguous leads, but NOT on reciprocal changes. There are not always reciprocal changes present, and reciprocal changes should not be relied upon when interpreting elevation.QUOTE]

EMSRUSH

1.It is hard to tell from the picture, but I do not personally see Elevation in V4, and non in V2.

2. It is infact good practice to know things that mimic ST elevation and use those as factors in your interpretation. If you know what LVH and BER look like and how to recognize it and you see them on a 12-Lead that has Elevation well then it is not a STEMI. It is LVH or BER.

3. As far as the reciprocal changes, what I was implying is. Say you feel like you might be looking at an inferior wall MI(elevation is creepin on 1mm), but you just are not sure. yet you see depression in V3, V4. Then bam, thats the confirmation you were looking for. Agreed there are not always reciprocal, all I was saying is that it adds fuel to your STEMI fire.

 

[medicsb]

I don't see any STE in V4, but there are only 2 ST segments to look at and they both appear to have some artifact.

The 12 lead is a pretty classic example of LVH w/ strain pattern, I'd file it away as a teaching point for a rainy day.

 

[EMSrush]

3. As far as the reciprocal changes, what I was implying is. Say you feel like you might be looking at an inferior wall MI(elevation is creepin on 1mm), but you just are not sure. yet you see depression in V3, V4. Then bam, thats the confirmation you were looking for. Agreed there are not always reciprocal, all I was saying is that it adds fuel to your STEMI fire.

Yes. Agreed.

 

[mikie]

Nstemi?

Unrelated: Spent some time in the cath lab recently (observing). PCI is truly fascinating sschtuff. (the last patient of the day was said to be having an AMI NSTEMI; there was a thrombus/occlusion in graft (previous CABG) going to RCA)


kinda related: In the absence of STE, how could you diagnose a NSTEMI? Reciprocal depression (ST depression) in the EKG? Q (patho) & T-wave changes?

 

[LondonMedic]

kinda related: In the absence of STE, how could you diagnose a NSTEMI? Reciprocal depression (ST depression) in the EKG? Q (patho) & T-wave changes?

Troponin.

Non-specific ECG changes in the presence of a history suggestive of cardiac ischemia are highly suggestive of NSTEMI but do not diagnose it.

In order to make the diagnosis, you need a positive cardiac enzyme test - either like Troponin T or Troponin I - and either a history of cardiac type chest pain or ECG changes.

Alternatively you can shoot their corries there and then, but that's rarely practical.

 

[mikie]

Troponin.

Non-specific ECG changes in the presence of a history suggestive of cardiac ischemia are highly suggestive of NSTEMI but do not diagnose it.

In order to make the diagnosis, you need a positive cardiac enzyme test - either like Troponin T or Troponin I - and either a history of cardiac type chest pain or ECG changes.

Alternatively you can shoot their corries there and then, but that's rarely practical.

Thanks! The pt. I saw did had elevated enzymes in the past 48 hours so I believe that was their concern.

 

[FL_Medic]

This is a good case.

ST-elevation in limb leads on a monitor strip is a good thing to note, but never warrants a STEMI Alert. This is because the monitor is not calibrated the same as when a 12-lead ECG is performed. 12-leads are much more sensitive and accurate.

The 12-Lead ECG does meet criteria for Left Ventricular Hypertrophy. With LVH, a Left Ventricular Strain Pattern may occur, frequently causing benign ST-elevation in the right precordial leads (V1, V2, V3), and ST-depression in the left precordial leads (V4, V5, V6). LV-strain can be identified in LVH by the presence of T-wave discordance (The T-wave is deflected opposite the terminal wave of the preceding QRS-complex).

This 12-lead does show signs of LV-strain, but what is concerning is the morphology of the ST-segment in V3. It looks like it is beginning to round over to a convex shape. Convex ST-elevation is always bad. Also, V1 has T-wave concordance with a near flat ST-segment, not good. The QTc is nearing the edge of normal limits as well; this could be contributed to the fact that it is a dialysis patient, and renal patients frequently show alterations in QT-interval and T-wave.

Another thing to note is the morphology in aVL. The ST-T changes in aVL are consistent with an inferior infarct. Meaning that aVL is very reciprocal to lead III, which is usually the first inferior lead to show an IWMI.

The T-waves are asymmetrical, a good thing, leaning on the side of benign changes. Symmetrical T-waves are never normal, and may be an early sign of an acute MI.

Taking all of these findings into account. Is it a STEMI Alert? No, not in my opinion; there isn't ST-elevation in two contiguous leads. V3 & V4 could be debated, and if they evolved at all or if there were any dynamic changes, i would concede to a different opinion. Is the patient having an MI? Maybe. Take them to a PCI facility, and if you can transmit... let the doc decide.

 

[FL_Medic]

I am well aware of some of the conditions that can mimic elevation. However, I'm not sure that it is good practice for me to pick and choose which ST elevations I treat as a confirmed STEMI and which I do not, with the exception of clear cut issues, such as a LBBB. It is, however, good information to keep in the back of your mind.

You should absolutely try to figure out if it is benign ST-elevation or not. Calling a STEMI may cost a lot of money; consider the on call cath team that has to come into work. Also, we should be trying to improve our abilities, and interpret a 12-lead as well as possible. This is just good practice. In turn, it will improve the care of actual STEMI patients.

Conditions that paramedics should be able to differentiate most of the time include:

LBBB
RBBB
LVH with LV Strain
Hyperkalemia
Acute Pericarditis
Benign Early Repolarization

These are some of the most common causes of ST-elevation. A myocardial infarction is not nearly the most common cause of ST-elevation. No, we aren't doctors, but considering we have less tools, it can be argued that we should be just as good at, if not better at 12-lead ECG interpretation than many physicians. Is that a realistic goal? No, maybe not, but I know many paramedics who can interpret ECGs better than quite a few physicians out there. Not that its a competition or anything...

 

[AEMT]

Well

Here is my thought... I did not see it on previous posts or maybe I missed.. You had said they gave nitro and Asa.. Come one people why do we do serial 12 leads or 12 leads after interventions.. Because things can change. I was not there so I don't know the whole story , also I am not a paramedic... I would really like to see the 12 lead before they gave the Asa and nitro.... So back to the basics... What happens when we give nitro plus and platelet inhibitor... Well we dilate the coronary arteries from the nitro and make the platelets less sticky with the asa... So what makes me wonder if it was not 100% occluded or if the nitro was able to open it up a little to allow some flow... Also seeing horizontal/ downsloping depression in lateral leads.... I would think this person is not doing to hot... But also again treat the or not the monitor.... It's hard to say without being there but very well maybe having an ami ... Atleast if the doctor says no not a stemi ... Ask hey just a teaching moment why not??? Good docs will give you a quick run down if not busy.... Atleast ours do.. Plus if during talk he found out pt had Asa and nitro when he previously did not know maybe his mind would have changed... 15 lead good idea why not ....

 

[KellyBracket]

Dialysis can be considered to be a "stress-test," and apparently your patient did not do so well with his test! Even without an EKG, and even with a negative troponin, further evaluation will be required in this patient. The clear evidence of LVH, i.e. subendocardial ischemia, does not exactly reduce his risk!

That being said, does anyone else think the precordial leads are a bit off? There should be a fairly clear progression of R-wave height as you run from V1 to V6. I suspect that the lead placement is somewhat off, with V2 a bit more lateral than usual.

 

[the_negro_puppy]

I am perplexed by the fact that this patient with a Hx of M.I's c/o chest pain (even if resolved) did not have a blood test for cardiac enzymes. Surely the attending would have considered a NSTEMI?

 

[LondonMedic]

I am perplexed by the fact that this patient with a Hx of M.I's c/o chest pain (even if resolved) did not have a blood test for cardiac enzymes. Surely the attending would have considered a NSTEMI?

Are we still talking about a dialysis pt? Does dialysis filter troponin, if not, the trop will be high and the reault pretty hard to interpret. The next question might be, what would the diagnosis change? If this pt has had several MIs, they should already be on antiplatelet therapy and if they're on dialysis, they're hardly a candidate for surgery or PCI.

 

[MSDeltaFlt]

Got an interesting call today, and wanted some feedback from you guys.

We received a Priority 2 call to an urgent care center for a 40 y/o male, possible STEMI. (Yes, we asked dispatch to repeat our response priority, too.) U/A, Pt was sitting up in bed, no visible distress, smile on his face. In condensed form, the conversation between me and the RN went something like this:

RN: This is a 40 y/o male who was having chest pain during dialysis this morning. EMS brought him in here. He's not having any chest pain right now, we gave him ASA and Nitro. The doctor noticed some changes when he compared an old EKG to the one we did today. [RN holds up a rhythm strip briefly] He has had three MIs in the past. Now, we're sending him over to ABC hospital to rule out a STEMI.
Me: Was there any elevation?
RN: I don't know. I don't think so.
Me: How are his vitals?
RN: BP in the 170's, Pulse in the 60's.
Me: Do you have his 12 Lead?
RN: Yeah, somewhere.
Me: Can I take a look please?
RN: Here.

The hospital's 12 Lead showed elevation in V3, V4, V5. It was about an hour old. I put him on my monitor (BP 175/102, Pulse 65, BPM 16, SpO2 100), and got this:

Next, I did a 12 lead and got this:

To make a long story short, we arrived at the ED and my 12 Lead was shown to the attending. He shrugged and said, "Not a STEMI" and walked away. I was perplexed; there seems to be clear elevation to me. Had I got this Pt as an emergency call, I would have called in a STEMI to the hospital. Can anyone explain to me why the attending said what he did? I realize that there's a few things going on in the 12 lead, but I don't see why the elevation was not significant. Please tell me what you see, and what you don't see.

Anyone care to take a crack at it? I realize the pics aren't the best, but give it a try anyway.

Yeah definitely not a STEMI. V3 isn't even close. For there to be ST anything it is in reference to the positive or negative deflection of the first wave at the beginning of the same complex relative to the isoelectric line. V3 has a positive R wave at the same level of the ST segment. Not a STEMI.

Might be a NSTEMI or at least an ischemic event, but no STEMI and I wouldn't even call that from the field.

 

[Jon]

EMSRush,

I would have checked and seen if they had run cardiac markers yet (perhaps they have an iStat?) and I also would have gotten a copy of the OLD 12-lead. Possibly even asking the doc WHAT he saw, so that I can relay it to the ED staff.

And do a 15-lead next time, too. They are quick, easy, and tell you so much more.

 

[AEMT]

Forgot to mention

I forgot to mention in my previous post... I really think v2 and v3 are reversed..

 

[BEorP]

This is not a STEMI,

The leads that have elevation are not contiguos and it has LVH. LVH can mimic elevation, I would have treated him the way you did. But no call on the STEMI.

And remember, those lifepaks are about 60-something percent accurate. Don't look at its interpretation.

On another note, if you are ever on the bubble as to wether this is a STEMI or not. Look for reciprical changes. Now let me ask you, did this one have any?

Though the sensitivity may be low, the specificity is quite high so if an LP 15 is calling STEMI, it probably is.

Source: http://www.physio-control.com/uploa...ment of Validation and Accuracy 3302436.A.pdf

 

[MSDeltaFlt]

Though the sensitivity may be low, the specificity is quite high so if an LP 15 is calling STEMI, it probably is.

Source: http://www.physio-control.com/uploa...ment of Validation and Accuracy 3302436.A.pdf

Never look at the interpretation first. Try to never look at it all. Nothing is more accurate than a properly trained human brain. This is not a STEMI. V2 & V3 do appear to be swapped. Still no joy on STEMI. No ST elevation. No reciprocal depression. There are inverted T's, but they are chronic in nature from previous multivessel disease with intervention as previously stated.

The fine print on the PDF file stated its accuracy assuming normal parameters. Said pt started out beyond normal parameters.

When in doubt, transmit (if possible) and consult with OLMC.

 

[boingo]

Is it just me or does anyone else see the need for a 15 lead EKG? I understand looking at R sided cx lead in IMI, however looking posteriorly, i.e. V7-V9 seems a bit overkill. I honestly can't think of a single case where I would see something in those leads that the standard precordial leads would miss.

 

[MSDeltaFlt]

Is it just me or does anyone else see the need for a 15 lead EKG? I understand looking at R sided cx lead in IMI, however looking posteriorly, i.e. V7-V9 seems a bit overkill. I honestly can't think of a single case where I would see something in those leads that the standard precordial leads would miss.

If you place your leads properly rarely would a right side or a 15 lead be necessary. IMHO.

 

[KellyBracket]

Isolated posterior wall MI s are definitely a small minority of STEMIs, but they are definitely out there, perhaps on the order of 4% of STEMIs. You probably get the information that you "need" form the standard picture, but getting someone else to get on board might require all the other leads for evidence.