50 year old male CC: Chest Pressure – Discussion

This is the discussion for 50 year old male CC: Chest Pressure.

We could not have been happier at the number of insightful comments we received on this case! Many of you caught on to our purpose for this case as we could not have picked a better borderline example!

When we last left our crew they were preparing to transport a 50 year old male who appeared acutely ill. Their first 12-Lead ECG suffered from excessive baseline wander, but appeared to have some ST-elevation present. Attempts were made at improving the quality of the tracings with little success.

Here is the initial 12-Lead ECG, this time with the computerized interpretation included:

This 12-Lead ECG shows marked baseline wander, sinus bradycardia, ST-elevation of at least 1 mm in II, aVF, and V4-V6 with ST-depression in leads aVR and V1. The monitor's algorithm believes the ST-changes are the result of Early Repolarization.

They attempted to troubleshoot the baseline wander with patient coaching, and after two more attempts they captured the following 12-Lead ECG; again with the computerized interpretation included:

This 12-Lead ECG also shows marked baseline wander, a sinus rhythm, ST-elevation of at least 1 mm in II, aVF, and V4-V6 with ST-depression in leads aVR and V1. In this tracing, just 2 minutes later, the monitor's interpretation has changed to read the ominous *** ACUTE MI SUSPECTED *** message, suggesting an inferiolateral infarct pattern.

Between these two 12-Lead ECGs we can clearly see that ST-elevation is present in leads II, aVF, and V4-V6 with ST-depression clearly visible in aVR and V1. It is difficult to tell with the baseline wander whether any PR-segment changes exist or if the J-point in aVL is depressed.

At this point our differentials should include:

  • Acute inferiolateral myocardial infarction
  • Pericarditis
  • Early repolarization

Given our patient's recent history of strep throat, diffuse ST-elevation, concave-up T-waves, and ST-depression in aVR and V1 we should strongly consider pericarditis. The baseline wander present makes accurate evalution of the PR-segment difficult, but a case could be made for PR-elevation in aVR. Compare our tracings with the discussion to 39 year old male CC: "Sick".

However, given the presentation of typical MI symptoms and a borderline ECG (albeit without reciprocal changes), we have no conclusive means of ruling out an inferiolateral myocardial infarction. If your service area has the ability to, it would be beneficial to transmit these borderline ECGs to a receiving facility for a second opinion. Compare our tracings with the discussion to 77 year old female CC: Chest Pain.

Our crew found themselves in quite the pickle!

In these instances it is prudent to err on the side of the patient and treat this as a STEMI, which is exactly what the crew did.

Upon arrival at the PCI center the following ECG was acquired:

The ED 12-Lead shows a normal sinus rhythm without ectopy. ST-elevation of at least 1 mm exists in leads II, aVF, and V4-V6. ST-depression is present in lead aVR. The monitor's interpretation is unknown.

The ED physician concurred with the activation and the patient was sent for an emergent cardiac catheterization.

No culprit lesion was found and the crew was later informed the patient was being treated for pericarditis.

This case represents a false positive, however, it is the author's opinion that this case does not represent an inappropriate field activation due to the borderline field ECG.

Some clues on the 12-Leads that favor pericarditis include a lack of reciprocal ST-depression in aVL, a normal QTc, concave-up ST-segments, and ST-depression in aVR and V1. When available echocardiography could be utilized to look for wall motion abnormalities prior to sending this patient to the cath lab.

When designing a STEMI system to provide maximal benefit to the patient a certain false positive rate is to be expected. The system must recognize the existence of this gray area and allow for overtriage in order to be successful for both the patients and their providers.

  • What are your thoughts on the conclusion to this case?
  • How many attempts at acquiring a clean tracing should be made?
  • If your system allows Paramedic activation of STEMI, are you provided constructive feedback?


  • Brad J says:

    Shocked….. I’m really surprised by this outcome because of how the patient presented. I wrote out a detailed explanation as to why I thought it was an MI in the original thread, but it looks like it doesn’t apply in this case. Always been taught and have always seen pericarditis not having ST depression. Good case…..

  • James says:

    I had a similar like scenario about two years ago with an almost identical patient.  After we performed our 12-lead, and suspecting either pericarditis or a stemi, we transmitted the 12-lead to the receiving hospital.  We did an emergent, code, transport to the facility following ACS guidelines.  The receiving facilities cardiologists agreed that this was a possible MI and a STEMI Team was activatied.  At the receiving facility, the pt was whisked to cath-lab very quickly.  The patient was found to have no lesions or blockages, and was treated for pericarditis.  We were given kudos for good patient evaluation, excellent interpretation, and exceptional swiftness of the call.  Call to cath lab door time was around 30 minutes with a 10 minute transport time.  Just proves that sometimes what we think is a duck is actually a goose.

  • Brian says:

    Anyone else seeing the PR depression in the ED ECG? There's also ST depression and (a hint I believe) of PR elevation in aVR, both of which also point to pericarditits. 
    I agree the prehospital mgmt was correct, however I wonder if it would've been more appropriate to obtain a stat echo in the ED to check for a WMA prior to or while waiting for the cath lab. 

  • Francis says:

    Maybe I am not seeing this correctly, but I do not see any ST depressions in AVR. I see a small (Less than 1mm) ST depression in II and elevated T waves and III and AVF have no marked T waves. Looking at this rhythm strip I would not conclude MI, but given his past history of of recent strep throat, I would consider Pericarditis. An Echo in the Subcostal view would confirm this suspicion. That being said, the crew did not do anything wrong. They considered the worst case scenario and treated the Pt. appropriately.

  • h dawg says:

    brian is spot on

    In my experience, physicians (should)will order a stat echo in the ED if the ECG is doubtful or questionable along with stat cardiology consult.

    This ECG had all the red flags of pericarditis. As soon as I saw that notched J point in the precoridal, I knew it for sure!

  • Carol Hughes says:

    Nice case. I had a recent transport of a 27y/o female with acute pericarditis. My first impression of this case was for pericarditis due to the strep hx and the concave ST. They young woman I transported had a pericardio window performed and they got 240ml of puss from it. She had ST elevation in all leads. She was a very sick young woman who thankfully waited until we arrived in the ER to drop her pressure and begin vomiting. She recovered nicely, I am told.

  • VinceD says:

    Nice point on this “false” activation actually being a sign of a working STEMI system. Recently we had Tim Phalen come by one of our local hospitals for a STEMI teaching day, and one of the topics that came up was the absolute lack of any false activations in our region. Rather than being a sign of super-competent medics, one of the cardiology leaders recognized that it shows only glaringly obvious STEMIs are being activated, while a lot of folks with less striking ECG findings are missing out on the benefit of timely reperfusion. We’ve gotta cast a wide net…

  • Michael Henry says:

    The 12 lead at the PCI center shows some borderline elevation in lead I. This can be indicative of pericarditis especially with the history or strep.  A better tracing prehospitally would have been more beneficial however the nature of the job can make it very difficult.

  • Kyle says:

    I just now looked at the EKG and my first thought was pericarditis.  I took a 12-lead EKG class by Dr. Amal Matu (may have mispelled his name) and he taught that if the ST elevation in lead 2 is higher then the elevation in lead 3, that is consistant with pericarditis.  Conversly, if the ST elevation in lead 3 is higher then in lead 2, that is consistant with a right ventricular MI.  I have confirmed this finding with local cardiologist and in comparison to a right sided EKG there always has been a RVMI.

  • I think this is great care. No question in the majority of PCI centers this pt is getting cathed. A 20 min Radial cath is pretty safe and too much risk if you are wrong. I get a sense on the ECG that there is some PR depression in the inf and ant- lat leads and the only thing I know that causes that is pericarditis. I’m also underwhelmed by any reciprocal change. One thing against pericarditis is a lack of tachycardia. I’ve seen many cases of pericarditis with abrupt onset that are quite painful so that part of the history is not that helpful.
    Technically this is a miss activation but I have. No issue caring this pt. We would reach back to our EMS crews to educate. There should be no chastising ever. Often the crew is in the Cath lab control room and we can give direct feedback.

    • Christopher Watford says:

      Dr. Dillon,

      I try and use the terms: appropriate, reasonable, and inappropriate (from Dr. Rokos). A clean cath means you had at least a reasonable activation, because they probably should not have made it to the table otherwise! You raise a great point: “there should be no chastising ever.”

      Systems of care need non-punitive QA/QI feedback loops in order to ensure providers continue to provide high quality care. In this case the crew is a part of such system, and received non-punitive feedback within 48 hours of the call from both the STEMI system coordinator and the department’s QA committee.

      Thank you for your feedback!

  • JJ Patrick says:

    I appreciate these case hx’s and the learning opportunities they provide, Cardiology is an area of great interest for me, occupational necessity aside. Your comment about the “inappropriate activation” made me think of something I would like to share though. During a recent NREMT refresher, a fellow student asked an ED Hospitalist who was presenting some case histories about “inappropriate activations” of cath/trauma teams. The physicians response, in essence, was he did not believe that there was such a thing; that if we EMS providers, in the field, make a judgement call based on reasonable subjective, objective and field diagnostic guidelines – we are never ‘wrong’. We have a fraction of the training, tools and information available to the MD’s, and if we are acting on what information we have in the best interest of the pt in our care – we are always right. I thought this worth sharing – thankful to work around such a fine Medical Director.

    • Christopher Watford says:


      Great points. When I provide feedback to my crews, I expect we will catch some gray area cases (otherwise we’re missing some STEMI’s). All that I ask is that they avoid the textbook not-STEMI (not to be confused with an NSTEMI). If they do activate, we’ll cover the human factors that led them to make the decision. Ultimately, our feedback contains an educational component regardless of the patient’s outcome. We can never have too much education!

      I also am thankful to work with medical directors who care and a STEMI system which is best in class.

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