Right sided EKG/Nitro

[ParamedicStudent]

Are you given any protocols on the use of a Right sided EKG and/or the use of Nitro with it?
I was taught to do a right sided EKG when you have an inferior wall STEMI, and you would switch v4 to the right side, but my question is what would you expect to see? Would you see STEMI in v4, as well as II, III, and aVF?

And do you use Nitro with with an inferior wall STEMI? I've heard of people using it, but I need to see what my county says specifically about that.

Also, since we're talking about EKGs, if you suspect a posterior wall MI because of ST depression in v1-v4, you would get the last 3 leads and place it on the left side of the back, on the horizontal plane. Would you also get ST elevation in those leads? How about Nitro for posterior?

 

[SpecialK]

There's never been good quality evidence for the use of GTN in STEMI. The original use of GTN was for angina.

However, yes, give them a spray of GTN and see what happens. If their chest pain or ECG changes improve then get worse again give them another spray. If not much happens then don't repeat it.

 

[STXmedic]

What do you think you would see in V4R in the presence of a STEMI?

Think of the precordial leads as cameras, each one taking a snapshot directly to the heart. On the printout, the machine doesn't know where you stick the leads (it assumes you placed them in the correct position, but doesn't know). It just gives you a printout of each lead's snapshot. So if you move V4 mirrored to the right side, the printout is going to show you whatever V4 sees (it's new view). So what is V4 seeing when it's placed on the right side?

Like you said, you need to look up your agency's protocols. For some agencies, it's an absolute contraindication. For others, they just say to use caution. Me personally, I'll just ensure that I have an IV first and that their BP is in an acceptable range. From what I've read, the dramatic plummet in BP when nitro is administered to an RVI is a bit overstated.

 

[TomB]

Are you given any protocols on the use of a Right sided EKG and/or the use of Nitro with it?

--- Our protocols recommend obtaining right-sided chest leads with acute inferior STEMI but it's rarely done in practice.

I was taught to do a right sided EKG when you have an inferior wall STEMI, and you would switch v4 to the right side, but my question is what would you expect to see? Would you see STEMI in v4, as well as II, III, and aVF?

--- Yes, that's the idea.

And do you use Nitro with with an inferior wall STEMI? I've heard of people using it, but I need to see what my county says specifically about that.

--- The answer is "maybe". We often blame RV infarction for hypotensive episodes when the patient was a poor candidate for nitroglycerin in the first place due to bradycardia and marginal blood pressure (often a manifestation of the Bezold-Jarisch reflex).

Also, since we're talking about EKGs, if you suspect a posterior wall MI because of ST depression in v1-v4, you would get the last 3 leads and place it on the left side of the back, on the horizontal plane. Would you also get ST elevation in those leads?

--- Again, yes. However, I often see this done in the presence of obvious acute inferior STEMI, and I'm not entirely sure what the point is. For acute isolated posterior STEMI, if modified leads V7-V9 show ST-segment elevation, there's no doubt that it's helpful. Just be aware that the posterior chest leads can be falsely negative. You don't "rule out" circumflex occlusion when there is an absence of ST-segment elevation.

How about Nitro for posterior?

--- For any patient, consider the whole picture, including heart rate, blood pressure, and physical exam.

Further reading

Right ventricular infarction (3-part series)

Acute inferior STEMI with right ventricular infarction and cardiac arrest

Acute isolated posterior STEMI: it's not anterior ischemia!

Posterior STEMI and prehospital tenecteplase (TNK)

 

[MedicIntern305]

There's never been good quality evidence for the use of GTN in STEMI. The original use of GTN was for angina.

However, yes, give them a spray of GTN and see what happens. If their chest pain or ECG changes improve then get worse again give them another spray. If not much happens then don't repeat it.

if its an inferior wall MI you are gonna wanna be cautious and make sure the patients BP meets your protocol meets the standards for giving GTN, if you diolate an inferior wall MI this could cause severe hypotension, also be cautious to use of viagra or male enhancements

 

[MedicIntern305]

if its an inferior wall MI you are gonna wanna be cautious and make sure the patients BP meets your protocol meets the standards for giving GTN, if you diolate an inferior wall MI this could cause severe hypotension, also be cautious to use of viagra or male enhancements

and ignore the typos my keys stick really bad due to ambulance mumps and chineese food dont mix well

 

[MonkeyArrow]

You can also check for RV involvement in the presence of inferior STEMI on the original 12 lead by looking for either elevation in V1 and depression in V2, or an isoelectric V1 and V3 and depression in V2. This is highly specific and sensitive for RV involvement.

 

[VFlutter]

You can also check for RV involvement in the presence of inferior STEMI on the original 12 lead by looking for either elevation in V1 and depression in V2, or an isoelectric V1 and V3 and depression in V2. This is highly specific and sensitive for RV involvement.

Also ST Elevation III > II is highly predictive of RV Infarct as well.

http://lifeinthefastlane.com/ecg-library/right-ventricular-infarction/

If it is a true RV infarct the name of the game is fluid, fluid, fluid. Avoid all nitrates and venodialtors.

 

[EpiEMS]

If it is a true RV infarct the name of the game is fluid, fluid, fluid. Avoid all nitrates and venodialtors.

What if we're BLS and don't know (or ALS but don't have a monitor around)? Are we better off withholding NTG, even if prescribed NTG is available?

 

[VFlutter]

What if we're BLS and don't know (or ALS but don't have a monitor around)? Are we better off withholding NTG, even if prescribed NTG is available?

If someone is prescribed nitroglycerin then they usually have known coronary disease and should be fine to give but take their vitals and assessment into account. Someone c/o of chest pain and SOB that is hypertensive and coughing up froth is different than the patient c/o chest pain and SOB that has a marginal pressure, JVD, and bradycardia.

But how often are you going to be giving nitro, that is not previously prescribed, without access to a monitor?

 

[VentMonkey]

Also ST Elevation III > II is highly predictive of RV Infarct as well.

http://lifeinthefastlane.com/ecg-library/right-ventricular-infarction/

If it is a true RV infarct the name of the game is fluid, fluid, fluid. Avoid all nitrates and venodialtors.

Perhaps even prime the line, and have them ready and connected to the saline lock in the event the patients BP suddenly plummets.

I have heard of this being done with suspected dissecting thoracic aneurysm patients.

 

[STXmedic]

What if we're BLS and don't know (or ALS but don't have a monitor around)? Are we better off withholding NTG, even if prescribed NTG is available?

The true bottoming out post NTG in RVI isn't as frequent as you'd think. I'll have to look for the last study I read, but I believe the incidence was around 10-15%. Considering true RVIs with hemodynamic instability are uncommon in the first place, it's probably pretty safe for BLS providers, especially if the patient is prescribed their own Nitro. Many RVIs that are heavily preload dependent tend to be borderline hypotensive anyway, which would make you debate giving NTG based on blood pressure alone.

Chase, it can be quite common depending on your area. In Texas it's very common for EMTs to be able to give Nitro regardless of whether the patient is prescribed it or not.

 

[VentMonkey]

What if we're BLS and don't know (or ALS but don't have a monitor around)? Are we better off withholding NTG, even if prescribed NTG is available?

Also, many other variables come into play with this scenario. Again, how far out is your ALS back up with their monitor and 12 lead capability?

Try and remember while NTG is a routine treatment for many MI patients, I think that ASA is still often down played by many prehospital providers in terms of it's importance in regards to improved patient outcomes in the event of ANY STEMI patient regardless of the location.

Our protocols now indicate that if there is ST elevation in 2 of the 3 inferior wall leads, to withhold NTG. Me personally? I have been a fan of this for sometime, and tried emphasizing this to my interns. B/L locks, some Zofran for N/V, Fentanyl for the pain, but first and foremost....aspirin! Awesome of Chase to point out lll (>) ll for RVI, as it almost always indicates a true RVI/ RVMI...be VERY cautious if you do proceed with NTG here.

Also, next time you're at a hospital for a STEMI alert look and see how important it is to the ED team to see that this patient gets ASA, and after ASA, probably some Plavix. These meds almost always supercede NTG and are true life-saving medications, IMO.

In short, for your scenario, you're better off making sure that their SPO2 (>/=) ~94%, and that they receive their ASA prior to ALS arrival. This would he stellar BLS care, I think.

 

[EpiEMS]

But how often are you going to be giving nitro, that is not previously prescribed, without access to a monitor?

Frankly, I never have -- and I don't really expect to. My question's more the "worst case" - which, as I somewhat expected, is unlikely.

QUOTE="STXmedic, post: 619786, member: 10304"]The true bottoming out post NTG in RVI isn't as frequent as you'd think. I'll have to look for the last study I read, but I believe the incidence was around 10-15%. Considering true RVIs with hemodynamic instability are uncommon in the first place, it's probably pretty safe for BLS providers, especially if the patient is prescribed their own Nitro. Many RVIs that are heavily preload dependent tend to be borderline hypotensive anyway, which would make you debate giving NTG based on blood pressure alone.

Chase, it can be quite common depending on your area. In Texas it's very common for EMTs to be able to give Nitro regardless of whether the patient is prescribed it or not.[/QUOTE]

I had seen something similar when I quickly searched PubMed - my worry was that I don't want to cause/worsen an immediate problem that I don't really have many options to deal with. Given that I can't "assist" with NTG without SBP > 100, I'm (fairly) comfortable with it.

Also, many other variables come into play with this scenario. Again, how far out is your ALS back up with their monitor and 12 lead capability?

Try and remember while NTG is a routine treatment for many MI patients, I think that ASA is still often down played by many prehospital providers in terms of it's importance in regards to improved patient outcomes in the event of ANY STEMI patient regardless of the location.

Our protocols now indicate that if there is ST elevation in 2 of the 3 inferior wall leads, to withhold NTG. Me personally? I have been a fan of this for sometime, and tried emphasizing this to my interns. B/L locks, some Zofran for N/V, Fentanyl for the pain, but first and foremost....aspirin! Awesome of Chase to point out lll (>) ll for RVI, as it almost always indicates a true RVI/ RVMI...be VERY cautious if you do proceed with NTG here.

Also, next time you're at a hospital for a STEMI alert look and see how important it is to the ED team to see that this patient gets ASA, and after ASA, probably some Plavix. These meds almost always supercede NTG and are true life-saving medications, IMO.

In short, for your scenario, you're better off making sure that their SPO2 (>/=) ~94%, and that they receive their ASA prior to ALS arrival. This would he stellar BLS care, I think.

I'm all about that ASA, the foundational BLS measure for ACS - I'm lucky* in that I usually have a medic onboard or responding <5min, but with winter coming, I never know if I'll be riding EMT/EMT at 2AM and ALS is delayed...or, worse, totally unavailable.

*Frankly, I wish I had medics available to me less often...it makes many of my colleagues weaker EMTs, because they don't want to or are afraid to manage the critical and emergent patient they're trained to deal with (that small percentage of calls).

 

[VentMonkey]

*Frankly, I wish I had medics available to me less often...it makes many of my colleagues weaker EMTs, because they don't want to or are afraid to manage the critical and emergent patient they're trained to deal with (that small percentage of calls).

Frankly, you sound more than capable of becoming, and ready to be a medic already to me.

 

[MedicIntern305]

If someone is prescribed nitroglycerin then they usually have known coronary disease and should be fine to give but take their vitals and assessment into account. Someone c/o of chest pain and SOB that is hypertensive and coughing up froth is different than the patient c/o chest pain and SOB that has a marginal pressure, JVD, and bradycardia.

But how often are you going to be giving nitro, that is not previously prescribed, without access to a monitor?

In my Area we aren't allowed to give nitro unless prescribed to patient! We do however carry it and can give with medical control only due to the fact of not knowing if it's an Inferior wall MI

 

[NPO]

I'll give you two sides to the same story...
First, our protocols state nitro is contraindicated with STE in II, III and aVF.

However, I had a very acute inferior MI (I watched it go from ST abnormalities to clear as day STEMI). v4r showed no right sided involvement and we gave nitro. The receiving ER doctor was our county medical director and he was happy with our treatment.

 

[VentMonkey]

I'll give you two sides to the same story...
First, our protocols state nitro is contraindicated with STE in II, III and aVF.

However, I had a very acute inferior MI (I watched it go from ST abnormalities to clear as day STEMI). v4r showed no right sided involvement and we gave nitro. The receiving ER doctor was our county medical director and he was happy with our treatment.

Ha, another very vocal EM attending at this very same SRC had the same reaction to my last STEMI Alert. As if to say "wow, you guys actually think n' stuff..." No worries, doc

To add to this, initially I was thinking perhaps an extensive anterior MI, as the patient was tachycardic, but alas, ST-elevation in lll(>)ll, so no NTG given.

Poing being, Epi, this particular patients ST-elevation resolved prior to ED arrival without any nitrates in the field.

MI's of all sorts can, and do often evolve with, or without NTG, hence the emphasis I place on serial 12 leads en route to the ED if time permits. And, yes even if the the ST segment elevation resolves prior to ED arrival, they're a cath lab candidate, as it's usually a temporary resolution.

 

[ParamedicStudent]

As relation to this topic and 12-leads. Do you do a posterior EKG if you get ST depression in the v1-v6 leads right? Nitro indicated?

And what is the significance of frequency response? How about axis deviation? We touched up on those subjects but didnt go too much into detail. Will read about it when i get a chance

 

[VentMonkey]

As relation to this topic and 12-leads. Do you do a posterior EKG if you get ST depression in the v1-v6 leads right? Nitro indicated?

And what is the significance of frequency response? How about axis deviation? We touched up on those subjects but didnt go too much into detail. Will read about it when i get a chance

Routinely? No, I don't perform a posterior 12 lead in the event I would suspect a PWMI. If there's clear cut ST depression in these leads, the patient is symptomatic, and meets all criteria for an AMI/ ACS work up, I see no reason not to trust my clinical judgement, and gut.

What exactly is it that you are unclear about regarding axis deviation? How can we help?