64 y.o. Female with CP – “And then I gave her a NTG…”

My apologies for the faded ECGs. Turns out the medic (a recent grad from our hospital’s program) had been carrying them in his work pants for over a week, waiting to catch me in the ED. The  patient had been brought to another hospital, but he wanted to review the ECGs with me.

They had been called for a 64 year-old woman at a gym, who had been getting ready for her Zumba class. She described an abrupt onset of precordial chest pressure, 8/10, that radiated to the jaw and left arm. Of note, the Zumba instructor insisted “We hadn’t even started the class!”

  • PMHx: HTN, but no CAD.
  • Meds: ASA daily, Prevacid

Vital signs:

  • HR – 70
  • RR – 20
  • BP 150/84
  • SaO2 – 98% RA

Aside from mild sweating, the exam was unrevealing. A rhythm strip was obtained:


And then a 12-lead:


And then a second ECG, with nonstandard lead placement as noted:


At this point, the medic gave a sublingual dose of nitroglycerin.


Clearly, this is a STEMI. What coronary artery is probably involved, and what areas of the heart are likely affected?

What do you think happens next?


  • Vera says:

    RV involvement, nitro reduces preload and leads to hypotension?

  • theresa says:

    Nitro should have never been administered by doing this that PT might have gone into cardiac arrest.

    • emt212515 says:


    • Richard Kenkel says:

      Cardiac arrest? Its a RELATIVE contraindication. You need to use clinical gestalt. Her blood pressure is quite high, and her heart rate is average, she would probably tolerate nitro quite well. Provided she’s not on beta blockers or calcium channel blocker, orthostatic hypotension etc, from what I can tell she’d compensate just fine.

      While there is a chance of her pressure tanking, In Canada we have PCP’s they can give fluids and nitro but not narcotics. Giving this patient nitro would be reasonable, because you can do something if the pressure tanks. If I was a PCP I would give nitro, and prepare for a bolus. I would not administer nitro without IV access. As an ACP however, I’d just jump to fentanyl because of the small chance she’d bottom out, and I tend to get better results with pain control.

  • Nimesh says:

    It is inferior Wall mi , RV involvement results in hypotension. Circumflex ar. Is involved.

  • JD says:

    I would suspect primary posterior/inferior involvement. I would give a 250cc bolus prior to any ntg admin. Immediately verify by right-sided 12-Lead then assess ntg use.

  • Roger says:

    RCA, inferior/posterior. III >II right side involvement, pre-load concerns. Hypotension/bradycardia that responds to positioning and fluid. Good read. http://cjem-online.ca/v15/s1/does-prehospital-nitroglycerin-for-chest-pain-cause-hypotension-in-acute-inferior-wall-stemi-

  • Roger says:

    With computer identified inferior wall MI’s (with/without RVI studied) showed no statistical difference in deterioration post administration of nitro compared to other locations/regions of infarction.

  • Clint says:

    RCA. Inferior MI. Would like to see posterior. Where’s V8 and V9?

  • Matthew Dyce says:

    Right sided inferior STEMI. RV involved here. Nitro should. Have been avoided due to dumping the preload. Starlings law. V8 &V9 can go on the same as V4R. Shows the posterior side as well. Only takes a few extra seconds and now provides you with a. Picture of the entire heart.

    • sean says:

      Stanley if this was a right sided MI you wouldn’t give nitro you would give fluids because the right side of the heart is volume based giving nitro would dilate that and decrease the volume causing the patient to bottom out if it was left sided you would give nitro because the left side of the heart is pressure based. Hope this helped a little bit.

  • Stanley says:

    I am a EMT-B, and I’m trying to understand why nitro shouldn’t be given (as stated in previous comments). We (as Basic’s) are trained to give it if there’s chest pain and the patient has it prescribed, and the vital signs allow for it. My question is since in my states EMT-B’s aren’t certed for 12 Lead EKG’s, then could us giving the nitro actually hurt the patient in the end with unforeseen complications? This is all assuming the prior comments were correct.

    • Amy says:

      Stanley, that’s a good question.

      There is concern (for paramedics and doctors) that when a patient has an MI that is affecting the right side of the heart, administering nitro (NTG) could cause a drop in blood pressure. As an EMT-B, you should stick with your protocols – if a patient has a script for NTG, they’ve been evaluated by a cardiologist in the past. They were given NTG because of their history/symptoms and the risks potentially outweigh the benefits – BUT, that is why you MUST have a good blood pressure. In some cases, NTG administration in a right sided MI can drop a systolic BP by 30mmHg or more. However, reading the article posted above on a retrospective study of prehospital MI patients, there did not seem to be a correlation between where the MI was and a drop in BP when administering NTG.

      Always, always, always get a blood pressure (and be sure of it) before giving NTG. That is why there are very strict rules for when you can or cannot give NTG to a patient (specifically low BP to begin with or use of Erectile Disfunction drugs within 48 hours).

  • Jessica says:

    Inferior wall MI with right side involvement, Right coronary artery involved, and this will effect the right ventricle. Giving this patient nitro could drop their pressure and even cause cardiac arrest. Pre load is what this patient needs, so fluid bolus. If the right ventrical isn’t in my terms pushing out the blood (poor cardiac output) then we try to fill up the left ventricle(preload) in order to push more blood out this increases the patients cardiac output. My protocols read use caution and contact medical control. I personally have never had a doctor tell me to withhold nitro (with right side involvement) this always makes me nervous. And I’ve never been able to find a study that says volume loading really does help.

  • Jake says:

    Inferior STEMI with RV involvement. The artery involved is most likely the RCA (STE in lead III > lead II, reciprocal depression in lead I, and RV involvement).

    I would have said her BP likely crashed after the NTG, but after looking at the study Roger linked to I’m less sure. Are there studies that contradict that one, or have we been basing our worries about crashing patients on anecdotal evidence?

    Based on my current knowledge, I would have consulted medical control before giving nitro to this patient, but her BP is high enough that I likely would not hesitate to give it otherwise.

  • Roger says:

    My overall question: Is nitro to blame? What is the relationship of decreasing pre-load triggering bainbridge and bezold-jarisch reflex? When pre-load drops our body compensates by vasoconstriction which in our case is antagonized by nitro so in order to sustain cardiac output I would expect a increased heart rate. Nitro has no negative effect on ino/chronotropy (http://www.ncbi.nlm.nih.gov/pubmed/6806462). Therefore I come back to: does decreased pre-load trigger atrial low pressure receptors to increase rate and volume over pressurizing the mechanoreceptors within the trabeculae of the left ventricle activating the bezold-jarisch reflex manifesting hypotension/bradycardia (increased vagal tone)? The reflex is sensitive to atropine and/or treated with positioning/fluids.

  • Roger says:

    How about this case review showing improved blood pressure with nitro. http://www.jmedicalcasereports.com/content/3/1/8782

    I think we have a lot more to learn, especially since we only recently (2005) hypothesized/tested a plausible mechanism for how nitro works via mtALDH (mitochondrial aldehyde dehydrogenase) synthesis of nitro into NO despite 150+ years of use.

  • Rob says:

    RCA involved. Right ventricle. No nitro. Even if the low pressure receptors kick in and raise rate not a good thing. Last time I checked anything increasing rate increased myocardial oxygen demand. In the presence of AMI it will increase the size of the infarct.

  • Roger says:

    I would still proposed judicious trial/use of nitro. Even the original literature from 1989 that raised the issue of nitro in RVI concluded that it should be “used with caution”. No statement made stating that it was contraindicated.

  • Marguerite says:

    Jessica and JD:
    You advocate fluids. Would you provide those even if you are withholding nitro and the patient is not hypotensive (this gal is written down at 150/84)?

    I read this as inferior and right sided elevation with reciprocal depression in I, aVL, and V2. Thus, I suspect RCA occlusion. I don’t see arrhythmia and the Qs and Ts are normal-ish consistent with an acute occlusion.

    I am an “EMT-3” in rural Alaska, and if this patient were mine I would have done the same thing, in a supine position. Nitroglycerin is worth the risk, in my training, and this is especially true in my extreme rural setting. The expected time for my patients from symptom onset to ED arrival is about 3 hours, if they dialed 9-1-1 promptly… I want to save SOME heart!

  • Nigel says:

    Hi, I totally agree with Roger. Ambo’s around the world appear to have this “inferior infarct = No nitro” idea drummed into them. Of course use with caution, but the patient’s BP was 150/84, why would you give fluids to an already damaged ventricle? HR, SPO2 and RR all ok, so no evidence of significant RV involvement.

  • Bryce says:

    I’m with everyone else’s answers, RCA, inferior mi right sided involvement etc etc, I would have still given nitrates given BP and pulse indicating no Vagal stimulation causes your hypotension and bradycardia. But I would also have a line and fluids up as a precautionary. Was and still is one of my favourite jobs to go to, have had good outcomes in these suckers

  • ScottU says:

    hate the right sided EKG. i don’t even consider V8/V9. they fail the “so what” test.
    V4R is elevated… “so what”. treatment is the same in the setting of elevation of II, III, aVf. ASA, O2, nitrates with caution with IVF. Transfer to definitive care.
    V4R not elevated, but II, III, aVf elevated. “so what.” Doesn’t change management.

    Most important treatment priority in either scenario is transfer to definitive care, either thrombolysis or intervention (intervention preferable in my opinion and there’s some data to support this for the appropriate institutions). Probably would avoid B-Blockade unless tachyardic. a lot easier to fix low BP in setting of inferior wall / RV infarct than bradycardia.
    V8/9 is abnormal or normal… “so what.” See above argument. Again, most important priority is transfer to definitive care.
    TIME IS HEART MUSCLE. If it’s my heart, don’t waste the time…. minutes, seconds whatever.
    Can’t remember the last time I did a right sided EKG or posterior leads in the ER. Maybe when I was a resident, as an academic exercise. In my opinion, doesn’t have any utility in the acute management and disposition of an acute inferior wall MI.

  • Dave says:

    Nitro drip would be preferred, but if all you have is tabs or spray – coronary arteries still need to be perfused. Get fluid going and give the nitro.

  • Nick says:

    Not all RVMI’s are preload dependent. You should anticipate that they are going to be and fill the tank before giving NTG. 2 larger IV’s connected to 2 1, 000 mL bags of NS. Give a bolus of at least 500 mL’s of NS befpre giving the NTG and prepare to give another 2L of fluid to bring their pressure up. Reguardless…….they still need the NTG for coronary artery dilation. Other things you can do is give Fentanyl for pain control if the NTG is not working because of a 100% occlusion. Relieve the pain……decreases myocardial workload and O2 consumption. So I agree with SCOTTU. The only reason the do a V4R would be to anticipate a possible drop in SBP because of vasodilation. You still need to treat. A V8/V9 is totally unnecessary because you can already see the posterior involvement from the reciprocal ST depression in the septal leads. Besides that, an additional posterior STEMI won’t change a thing you do as far as treatment. The RVMI does.

  • chris says:

    Posterior/inferior. Hold the nitro give at least a liter or two of fluid. Nice 15 lead! We have a short transport time to our local hospitals no drips for us.

  • cory says:

    Stanley I too wondered this when I went to the Advanced care paramedicine program. We were always taught as BLS if pressure allowed and no other contraindications to give nitro for ischemic cx pain. Because of the inferior part of the heart bieng preload dependant, as an ALS provider we are to place v4 on the right side of the chest and check for any elevation and even with this reading, can proceed with caution. a patent IV line and 1000 ml bag of saline should be a must prior to this though.

  • kyle says:

    2 large bore iv’s and give the nitro with that bp. i suspect the patient was okay, given the initial bp. but i think failing to secure iv’s first was potentially negligent.

  • Cameron MD says:

    Roger and others make some great valid points, and reference some great articles.

    However, a HUGE take home point: what four things have been shown and proven in the literature to decrease 30 day morbidity and mortality with A
    a STEMI?

    Beta blockers- though no literature supports that they must be given immediately, but should be give within 24 hours to aid in myocardial remodeling
    D2B time ( door to balloon time). … Though I have my ‘personal’ opinions on this but I will keep them to myself for this line of discussion

    Take home msg: NTG has never been shown to decrease 30 day morbidity and mortality.

    Why we rush to give NTG in the pre-hospital settings or in the ED for that matters, I do not know. No really smart doctor has any shown me any evidence based medicine for NTG in the settings of a STEMI! Though maybe I will follow this thread and learn something! 🙂

  • JJ says:

    We had a similar case sent out via email by one of our clinical supervisors. They claim with inferior MI, you CAN give NTG IF the pressure is high enough. The case emailed was 164/90 NTG was given and only dropped it to 150/80 or so. I understand that it will decrease preload and the RCA is responsible for preload. However I am just reiterating what was told and would like to see if anyone else has been told by supervisors or medical directors.

  • Darren says:

    Thank you, Cameron MD! I completely agree!

    This patient has an RCA occlusion, likely proximal to the right marginal branch, thereby causing right ventricle involvement. The right ventricle is responsible for blood supply to the left ventricle, and is dependent on the preload coming from the vena cava. No blood in = no blood out.
    As Cameron stated above, nitro has no proven benefit in survival, despite the logic of improved blood flow to the myocardium. Cardiogenic shock, however, which you stand a very good chance of inducing if you give this patient sublingual nitro, has a very significant history of killing people. To me, the risk vs. benefit of sublingual nitro administration here doesn’t pan out in favor of the patient.
    My treatment? Aspirin, at least 2 large bore (at least 18 gauge) IV’s, consider low dose IV nitrates, consider opiates but watch blood pressure (morphine will mess with preload here too), and rapid transport to an appropriate facility. Be ready for fluid bolus if necessary. Anticipate the possibility of this patient developing SA or AV nodal blocks. Pads wouldn’t be a bad idea.

  • David Cokely says:

    Can’t wait for this guy to get burned. He clearly had the foresight to do a v4 right sided lead which showed ST elevation indicating a right sided mi. It would have been better off had he not done the v4r if he was really so dead set on giving nitro. Now if the patient coded and went into cardiac arrest he would be 100percent at fault. It’s bad medics to make bad decisions like thismake the rest of us look bad..I hope that at the very least he had an IV in place before giving the Nitro. This is one of those situations where you definitely want to have an IV in place before you do anything else. Furthermore, if it was a protocol issue terms of all chest pain or get mone up which i think is something dangerous to teach, he should have consulted medical control and ask md override can not give the Nitro.

  • Stuart says:

    That’s a pretty bad attitude, David, for someone just being thorough at their job.

    I was taught be cautious when giving NTG if suspecting RV infarct due to reducing preload, but nowhere have I seen any research showing it can cause cardiac arrest! Is this just anecdotal evidence?

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