Here is the conclusion to 72 year old male CC: Unknown problem (man down)
Here was the initial 12-lead ECG.
Based on this ECG the lead paramedic called a "STEMI Alert" and transmitted the ECG to the receiving hospital.
The on-duty ED physician received the ECG and the paramedic's radio report.
The ED physician called up the patient's records on the computer system. It turned out that the patient had been to the hospital before.
There was a copy of a prehospital 12-lead ECG from March 2009 on file in the patient's chart.
Based on the similarities between this ECG and the ECG recorded on this call (and the fact that the presentation did not exactly scream ACS) the ED physician did not call the "Code STEMI" while EMS was still in the field.
It would prove to be the correct decision.
This is the 12-lead ECG that was captured on arrival.
You will note that this ECG is very similar to the prehospital 12-lead ECG captured back in March 2009. However, it's slightly different from the prehospital 12-lead ECG taken earlier that evening.
Go back up and look at the prehospital 12-lead ECG.
The frontal plane axis is off by about 15 degrees, the T-wave inversion in lead aVL is more subtle, and the R/S ratio in lead V2 is > 1.
Since these findings are not present in the 12-lead ECG taken on arrival at the hospital, it can probably be explained by lead placement.
Paramedics often project that attitude that skin prep and electrode placement are a low priority, but this case demonstrates why it's essential to quality patient care.
With careful lead placement and excellent data quality, the GE-Marquette 12SL interpretive algorithm does not give the ***ACUTE MI SUSPECTED*** message.
In addition, the ST-depression / inverted T-wave was a critical finding on the prehospital 12-lead ECG, because it suggested the possibility of a reciprocal change to the spurious ST-elevation in lead III.
The presence of the inverted T-wave on the "old" ECG made the ED physician take this finding with a grain of salt.
There's nothing wrong with having multiples sets of "critical eyes" looking at an ECG prior to calling in the cavalry, especially for a marginal ECG where it's questionable as to whether or not the "1 mm of ST-segment elevation in 2 or more anatomically contiguous leads" criterion is met.
That's how we minimize false positives, control health care costs, and do the right thing for the patient.
So we're 0 for 1 with our STEMI Alert protocol. However, on this particular day, the system demonstrated a hidden strength! The STEMI Alert allowed for a quick comparison to an "old" ECG.
I hope the medic viewed this as a win win situation and wasn't offended at the MD's choice.
Firefighter/Paramedic -I think the treating paramedic was doubting himself and wondering if he did the right thing calling the STEMI Alert.I'm sure he wasn't offended.Tom
I’m sometimes appalled at the poor placement of electrodes. Does anybody teach this anymore?Another aspect of lead placement that isn’t stressed as much as it should be is the importance of pt position. Let’s say you have a pt that is lying on the couch. You do the 12 and it’s diagnostic for STEMI. You now put the pt on the stretcher in semi-fowlers. The position of the heart has now changed with relation to the electrodes. Furthermore, the position of the electrodes has likely changed due to forces of gravity on flabby skin.I try to shoot a 12 as soon as the pt is on the stretcher in a position of comfort. Now I know that serial 12s will be comparable in terms of electrode position relative to the heart.
CLARIFICATION: I don't wait until I get the pt on the stretcher to shoot the 12. If I have a pt that is suspect for acute changes, I will shoot a 12 immediately but once I get them on the stretcher, I'll get another shot as my benchmark for the serial 12s. That way I know the pt is in a similar position.
G.W. – I agree with you! Lead placement tends to be sloppy, both inside and outside the hospital.I can see where it might be difficult to learn how to find the landmarks for lead V1 and V2 in some patients, but you'd think we could figure out how to place the limb leads on the limbs! That's just paramedics being stubborn or not believing in the merits of appropriate limb lead placement.I usually capture my 12-lead ECGs with the patient resting in a comfortable semi-Fowlers, breathing normally. Tom
And if they are not breathing normally? LOLCall me Bill. That silly gmail account thing puts that there.
I have a couple questions about how this case progressed. Does the LP 12 use only the limb leads to calculate the axis? When we received our initial training, we were told (and I double checked the LP 12 manual), that anywhere on the limbs is acceptable, but most often on the wrists & ankles. I have also heard to avoid bone. If the axis is determined by the limb leads, how does limb lead placement affect axis? I understand how patient positioning affects axis (supine vs high fowlers), but if the patient was in the same position and the leads were on the limbs, could it still change?I guess my question is, how would lead placement affect aVL? The depression in aVL doesn't seem to match the apparent slight elevation I see in Lead I. On the prehospital 12 Lead.Does anybody have any strips of early or late transition after they moved the electrodes? I tried on myself the other day and couldn't get a change while reasonably close.This shows how much we can learn by critiquing oneself. Always gotta love the looks you get when somebody "slaps" some patches on and you move them.Thanks again & please keep up the great work.Geoff
Out of curiosity, is it known if the medic administered MONA treatment prior to consultation with the MD? Or does this system require consultation prior to MONA? If I had seen the EMS strip and then at hospital strip – without a MD interpretation in between – I might have speculated that nitro might have spontaneously resolved the STEMI, which is a discussion we've had in the past.