Inferior vs anterior wall MI's

Specialties Emergency

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Hey there! I need help understanding the course of treatment for when a pt has a right sided or verntricular MI vs. a left ventricular MI. Right sided you want to increase pressures and preload, while in left you want to decrease?

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So, inferior MI involves the RCA and anterior, the LAD. Sounds like you got that. The RCA is perfused over both diastole and systole as opposed to the left sided system which is just during diastole. When you say "increased pressures and preload" it doesn't mean drive them with a lot of fluid and pressors. It means be careful with things like NTG or narcotics and give inotropic support early if necessary to keep the MAP around 70 or so. Giving fluid should be goal directed, ie. a positive leg lift test.

That's the right side...when dealing with the left side, again, "decreasing" the systolic pressure just means don't let it go too high because that increases myocardial work and O2 consumption. Also, an elevated diastolic (greater than about 90 or so) raises myocardial wall tension which raises the pressure gradient the coronary blood flow must overcome to perfuse the subendocardium of the left ventricle.

As always, keeping the HR below about 90 is critical either way. Bottom line is if you keep the MAP at least 70 and no greater than about 85-90, you'll do fine whatever vessel is involved.

Specializes in Urgent Care NP, Emergency Nursing, Camp Nursing.

Even simpler: if inferior wall MI (i.e. II, III, aVf), then no NTG.

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What if you see ischemia in a lateral lead too?

YoutubeTheNP

221 Posts

Specializes in ER, PCU, UCC, Observation medicine.
Hey there! I need help understanding the course of treatment for when a pt has a right sided or verntricular MI vs. a left ventricular MI. Right sided you want to increase pressures and preload, while in left you want to decrease?

Right sided MI's, you want to avoid NTG / Morphine. These MI's tend to bottom out the BP. Sometimes you need to fluid resuscitate.

Left sided MI, NTG and Morphine is OK.

Just to state the obvious you are also activating cath lab while doing all this, lol.

There is also literature on the use of supplemental O2. If the pt sats fine on RA, O2 is not recommended as it can constrict the coronary arteries putting more strain on the heart, research has found.

Keep in mind anything in the real world is possible. What you read and study in a textbook will not always be what you see in real life. Each case is unique. Manage your patient from how they look, and look at your data, labs, VS, etc to determine treatment.

YoutubeTheNP

221 Posts

Specializes in ER, PCU, UCC, Observation medicine.
What if you see ischemia in a lateral lead too?

inferolateral wall MI. Again nothing is set in stone. Look at your pt. If their BP is tanking, common sense tells you no NTG. You can't just treat the EKG, you have to look at the whole picture. I've had EKG machines read *****Critical Alert**** ***** STEMI****** and the machine is interpreting it wrong.

Specializes in Urgent Care NP, Emergency Nursing, Camp Nursing.
I've had EKG machines read *****Critical Alert**** ***** STEMI****** and the machine is interpreting it wrong.
So have I, but the pt had pericarditis with ST elevations in all leads, so I couldn't blame the machine.
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