Chest pain and ST-segment elevation that resolves after nitroglycerin

Here’s an interesting case that illustrates the value of prehospital 12 lead ECGs.

A 66 year old male became suddenly ill while playing tennis. Bystanders state that he struck the ball with his racket, staggered a few steps, placed his hand over his chest, and sat down on the tennis court.

9-1-1 was contacted immediately.

Past medical history is significant for hypertension, hyperlipidemia, and a “previous episode of chest pain” for which the patient carries SL NTG which he rarely takes PRN for chest discomfort.

A paramedic from out-of-town was present on scene and gave the patient his own NTG.

On EMS arrival, the patient appears acutely ill. He is diaphoretic and weak, complaining of chest pain.

Vital signs are assessed.

  • HR: 72
  • RR: 20
  • NIBP: 88/58
  • SpO2: 98% on room air

The cardiac monitor is attached.


Even in monitor mode, you can see ugly looking ST segment elevation in lead III with reciprocal ST segment depression in lead I.

A 12 lead ECG is captured.


The ECG shows acute inferior STEMI. There are Q waves in leads III and aVF with ST segment elevation. There are downsloping ST segments in leads I and aVL which represent reciprocal changes.

The 12 lead ECG was transmitted to the hospital and the cardiac cath lab was activated.

Paramedics placed the patient on oxygen, gave 4 baby aspirin, started an IV, and administered a fluid bolus (I do not have the next set of vital signs but we can assume the pressure came up with the fluid bolus). The patient was given SL NTG and 5 mg of morphine.

An additional 12 lead ECG was captured less than 10 minutes later.


The ECG is now non-diagnositc.

If not for the prehospital 12 lead ECG, there’s no telling how long this patient would have sat in the emergency department.

Instead, the patient had a 39 minute door-to-balloon time.

If you know any old-school paramedics, medical directors, or administrators who care about patients but still aren’t sure prehospital 12 lead ECGs are necessary, be sure to share this case with them!


  • TxMedic83 says:

    Do we know what the results of the PCI procedure were? Curious how much disease this gentleman had… Nice case!

  • SoCal Medic says:

    Very nice case Tom, great job on all those involved.

  • Brian T says:

    Ntg and Morphine to an inferior MI with a pressure of 88? Were right sided leads done?

  • Tom B says:

    Brian – I personally don’t see much point in performing right sided leads with an inferior STEMI and a pressure of 88. I would just assume right ventricular involvement and treat accordingly. I wasn’t on this call, but I know the treating paramedic and I’m certain she wouldn’t have given the NTG and MS if the pressure hadn’t improved with the fluid bolus. The follow up BP on the code summary showed extreme hypertension that I’m assuming was a spurious reading. I’ll ask Tina about it next time I see her. Good point though! Tom

  • Tom B says:

    TxMedic83 – I’ll see what I can find out about the procedure.Thank you SoCal Medic!Tom

  • Shaggy says:

    What I am impressed with this scenario is the 12 lead was performed before treatment interventions were performed, capturing the MI and ischemia. I always try to impress this on others but the old practice still remains of treating the patient then moving patient to truck and doing intial 12 lead there. This is an awsome case in favor of getting the 12 lead first.

  • Tom B says:

    I got the results of the procedure today. RCA was 99% occluded mid-body with a recent thrombotic lesion. LAD was partially dissected.Tom

  • Anonymous says:

    Tom, going back to the occluded RCA question. The American Heart Association states that in the presence of RCA involvement GTN should be contraindicated and Morphine should be given in small doses. Even if you don’t do right sided chest leads, for some having a inferior infarction with bradycardia and hypotension one has to assume there is RCA involvment. Since the right side of the heart is dependent on preload all GTN is going to do is reduce this preload. I know you know all this one dose of GTN at that blood pressure could send our patient into arrest.

  • Tom B says:

    May I please know where the AHA says that?Tom

  • Happy EMT- I Tech says:

    I am one of those people who do a 12 lead bfore any interventions. It takes less then 2 minutes to hook up print off and send. After that 12 lead and after each round of interventions. Yes I have taken some crap over this , but I want to know what is going on b4 any interventions then see what the interventions have done….. I have also heard Vr4 lead ST elevation should not get nitro.. I am not a paramedic nor is it in my protocols to not administer it for Vr4. So maybe I am wrong but just what I have been told.

  • Dave says:

    Well, I believe this a great case, in fact im hanging this up at my fire department and sending it out to my EMTs.

    I really do enjoy reading everyones blogs, and this is a great way of training.

  • re: right-sided leads

    for me the right-sided leads are to help identify possibly RVI and determine the course of treatment (basically ntg or fluid first). if, as tom said, it’s suspicious enough for RVI, i also don’t see much use for right-sided leads.

    that being said, right-sided leads should be done with all inferior STE if you aren’t sure about whether or not it meets RVI criteria.

  • baha says:

    some one else can say that the take of  aspirin might be the causal agent  of aborted inferior STEMI !!

  • Wayne says:

    I agree it's important to gain knowledge of whether or not RV is involved in Inferior STEMIs. However, a very useful tip once given to me by a wise cardiology consultant is: If STE is greater in lead III than that of lead II then there is a 95% likeyhood that it is the RCA that has occluded. If STE is greater in II than III then it is 95% likely of LCx occlusion.
    I have found this to be very useful in aiding my decision of RV involvement without the use of RV4.

  • MEDICNYS says:

    Great Case!!!
    Brian – If you are presented with a Inferior STEMI why waste the time looking for RVI?  You are going to treat the same way…  Also if the RV was really affected you would not see a PSO2 of 98% RA…  This is a stone cold Textbook STEMI in the Inferior wall of the LV. Performing a RV 12 ld would just waste time to intervention.

  • Medic2011 says:

    This is the best case!!!  Thank you for sharing, I'll not forget this scenario.

  • Mike says:

    MedicNYS- There are definitley different treatment methods to a plain IWMI and a RV, like others have stated with RVI your heart is purely pre-load dependant, you give NTG and there goes that preload, so there are some differing modalities to look at with regards to IWMI and RVI.  Also I don't quite understand why you believe a spO2 of 98% would be impossible with RVI?? 
    And finally, does it reeeaaallly take that long to move ONE lead to the right side and push the button again? 🙂

  • FL-Medic says:

    Intersting case, but Tom's cases are always interesting!!! props to TOM).  A few questions came to mind: 1- why did the "on scene medic" give the patient his own NTG without knowing the patients B/P?. 2- At what point is it ok to give NTG after a fluid bolus raises B/P – do you wait till the B/P is > 100 systolic?
    I know, as Tom said, there is more to this story, but the illustration of his point being – "Get the evidence before you treat" (to show the ED/Cardiologist) is always a good idea – It's the same as performing a complete patient assessment, it may take an extra 2 min. but the time saved will be on the Door – Ballon side of the case.

  • Eff Dogg says:

    I like what is being said so far! the sad thing is I met a medic that only does 12 leads for chest pain ie. if you were SOB, diaphoretic, nauseaous, pale, presyncope, and hypotension… she wouldn't do a 12 lead because you didn't have "chest pain"! and i can't explain to her otherwise 🙁   I also met one that didn't do a 12 lead on principle stating that the ER would do their own anyway… but he was kinda weird 🙂

  • Vera says:

    Please explain to a total newbie: meds can normalize the EKG while the patient actually keeps infarcting?  And would transient conditions, such as Prinzmetal's, only cause ST-depression, so once you have seen elevation, you assume it is definitely not something transient? thanks!

  • Vera says:

    P.S. and if I am JUST looking at the second EKG, the Q-waves in inferior leads should make me think of  an old MI and not worry there is an actual emergency?

  • Ben says:

    Just seeing this thread now, but in response to TomB’s request for the guideline that contraindicates NTG in RV infarct, it’s the ACC/AHA Guidelines for the Management of Patients with ST-Elevation Myocardial Infarction (free PDF at the Circulation site). It’s listed as a class III, LOE C intervention for hypotension/bradycardia/RV involvement. I’ve been guilty of treating these patients exactly as the treating medic did for years, but this guideline was just recently pointed out to me, and now I’m second-guessing what’s really “right” for managing these patients…

  • Tom B. says:

    Ben, thanks for the reference. I still think there's a difference between a patient with ST-elevation in lead V4R and a patient with signs and symptoms associated with the hypotensive syndrome of right ventricular infarction. The article I just wrote for my column at shows a patient with acute inferior STEMI, complete heart block, and a heart rate of 34 (and probable RV infarction) who received NTG and the pressure bottomed out to 61/25. I think we're all agreed that's bad. On the other hand, with IV access, and maybe even a preemptive fluid bolus as needed, I see no reason why a patient with acute inferior STEMI, sinus rhythm at 88, and a pressure of 160/90 shouldn't receive a trial dose of NTG. The issue I see is that the treating paramedics aren't considering the possibility of RV infarction at all and weighing the risk/benefit. They're just seeing a systolic presssure greater than 90 and giving nitroglycerin. It's an education thing.

  • kyle says:

    Tom, I think you've exemplified the point.   To administer that preemptive bolus, you really need a good look at the 12 lead.   someone having c/p, and a bp of 104/60, with a hr of 82… could easily be having right sided involvement.   Even with a hypertensive case like the one you described, you need to be very careful with that ntg if the infarct is right sided.  Plenty of cases out there where bad things have happened for failure to manage preload.

  • Matt says:

    Great case Tom and thanks for all the awesome work you and your team does. In regards to the NTG, it’s not an absolute contraindication, but I would just not give if I suspected it would augment the preload negatively. I don’t like chasing things if I don’t have to. Honestly NTG has never been proven to decrease mortality or mobidity in ACS/STEMIs. The AHA recognizes this but takes a pretty soft stance. I think going with the MS or Fentanyl or Dilauded alone would probably be the safest approach no matter if RT sided or not. Thoughts Tom?

  • alex says:

    How hard is it for some people to get a V4R? It takes less than 30sec and could mean the difference between your patient arresting with the next GTN.

  • Iliyas says:

    Inferioposterior mi

  • Mark A Shima MD FACC FACP FSCAI says:

    Tom very nice demonstration that even transient ST elevation may be associated with STEMI. In some cases the angio will show a partially reperfusion RCA with haziness c/w recent thrombus. Ulceration of the lesion or lesio cap dissection is also fairly frequent. Finally never forget the benefit of the early serial EKG at approx 10 minutes post presentation. I have had one case of true focal spasm with a similar presentation
    Keep up the great teaching!

Leave a Reply

Your email address will not be published. Required fields are marked *