Friday, June 5, 2009

ST elevation on prehospital ECG is gone upon arrival to the ED

This is a 55 yo male with chest pain. The medics recorded the first ECG, which shows unequivocal ST elevation in leads V4-V6.


Our medics have the authority to activate the cath lab from the field, and they did so. After arrival in the ED, the second ECG was recorded.

There is no significant ST elevation here. It has resolved spontaneously. There is ST depression with hyperacute T waves, best seen in lead V3. This has been associated with 3% of LAD occlusion (http://content.nejm.org/cgi/content/extract/359/19/2071).

The patient had LAD occlusion; because of the prehospital ECG, and the authority to activate the cath lab, his door to balloon time was 36 minutes. Had there been no prehospital ECG, there may have been no coronary intervention at all because of the absence of ST elevation in the ED.

9 comments:

  1. These jobs give us paramedics the "warm and fuzzies".

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  2. Interesting case. Did he require stenting? Was there thrombus present on angio or just stenosis? Did he have any anginal equivalent symptoms prior to this incident?
    Thanks-

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  3. In answer to medicnick, there was thrombus present and a stent was placed.

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  4. How often does this happen (abnormal ecg that resolves itself)? And in cases like this, is the abnormal one the one we should base our treatment off?
    I am still in medic school, and I remember a case where we put a pt (whos cc was a low pulse ox reading at a nursing home) on the monitor solely because I needed one more strip for the semester. It also showed signigicant st elevation. After seeing this we switched him over to the 12 lead and the elevation was gone. No one could explain to me what or how that happened. For whatever reasons the medics dismissed the first ecg and disconnected him from the monitor. While en-route the pt went unresponsive for about 30 sec or so. Just short enough that we didn't get the episode on the monitor. After he came to the monitor showed frequent, multi-focal pvcs which by the time we got him into the ed, had turned into runs of vtach (we had a very short transport time). My question is this: should we have been more concered with the first ecg and should we have been more aggressive with our initial treatment based on that dispite the normal looking second ecg?

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  5. Monitor strips are not very reliable for ST elevation because the leads are often placed differently. However, whenever you see this, you should immediately get a 12-lead because it may mean actual ST elevation and you wnat to capture is before it resolves spontaneously.

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  6. Very same happened me, st elevation had resolved by the time we got to hospital but patient went to cath lab on our ambulance trolley! soley on the findingd of our 12 lead :-)

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  7. Kindly please explain how/why the EKG resolves itself when there is obviously a problem requiring intervention. Also, how can we be more careful in the field in identifying such problems?

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  8. Coronary thrombosis is a dynamic process, with thrombus forming and lysing (occluding and reperfusing the supplied myocardium). Even though the artery has spontaneously opened, and the supplied myocardium reperfused (resolving the ECG findings), the unstable exposed coronary plaque and fresh thrombus are still there to activate platelets and form more clot. So intervention is necessary and improves outcomes.

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  9. there could be spasm or perhaps paramedic intervention with pre cath 5000units heparin gave some resolution happened to me recently and pt had big proximal LAD occlusion

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