# 3 lead ecg



## emt_irl (Feb 8, 2010)

while monitoring a patient on lead II last week, i noticed a normal sinus rythm... well mostly normal had normal p waves and t waves.. but the qrs was upside down.

now i know a positive electrical impulse will make an upward deflection on an ecg, what would cause this downward defelection?

a blockage of some sort?


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## Lifeguards For Life (Feb 8, 2010)

An inverted QRS complex in lead II may be a pathologic Q wave. A pathologic Q wave is indicative of a previous MI, and once they develop, they rarely cease to appear on an EKG.

This inverted QRS complex could also signify Left Anterior HemiBlock, a common underlying cause for a Left Bundle Branch Block. Incomplete Left Nundle Branch Block occurs in 2 forms, each known as a hemiblock. In Left anterior Hemiblock  transmission of the electrical impulse proceeds normally along the main left bundle branch and the posterior fascicle, but it is blocked or delayed in the anterior fascicle. This blockage results in delayed activation of the anterior portion of the left ventricle.


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## emt_irl (Feb 9, 2010)

i suspected a block of some sorts.. thanks for that.

i advised the person to get a 12 lead done just to be sure everything was ok, and he refused as if he didnt want to know if something was wrong.


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## reaper (Feb 9, 2010)

emt_irl said:


> i suspected a block of some sorts.. thanks for that.
> 
> i advised the person to get a 12 lead done just to be sure everything was ok, and he refused as if he didnt want to know if something was wrong.



Best advice you could give him.

Lead II cannot be used to diagnose anything. It is there to tell you a rate and that is all.

If you are looking for diagnostics, then you must have 12 lead or at least an MCL1 lead.


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## mycrofft (Feb 9, 2010)

*Sincere dumb question...reversed leads?*

Oh, by the way, I had an echocardiogram done yesterday and the EKG they performed during the test (in a quiet and stationary room) was very detailed but used two leads on my right sholder and one on my left chest. Period.


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## Jersey (Feb 9, 2010)

whooooaaa. Lets back up here.

An inverted QRS complex in lead 2 is most likely to do with an axis deviation that is "normal" for that person, blocks and other more "scary" stuff is not possible to diagnose with lead II. 

As for the lead on the shoulder/left chest that seems like an interesting MCL6/MCL1 variant, this is commonly used to provide a rhythm check, but can't provide a detailed look at the heart like a 12 lead can, even in a quiet room. It provides a GREAT view of the ventricles, but can't provide a look at segmented parts of the heart. 

Did you ask your partner after the call what he suspected was up? Voicing concern is a great thing, it prevents the human factor and keeps everyone working at their best. You did the right thing.


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## lightsandsirens5 (Feb 9, 2010)

Errmmmmm.....I could be wrong, but couldn't an upside down QRS be caused by putting the leads on wrong too? Or am I mistaken?


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## emt_irl (Feb 9, 2010)

no trust me the leads were on the right way as my partner double checked for me. im not that bad hahaha and 20 minutes later we had another guy on the ecg and he had a text book normal sinus rythm so nothign wrong with machiene or emt.

i had also heard that theory alright about axxis deviation, or in lay mans terms the heart at a slightly different angle but again could be normal for him.. i know the guy hope to hear from him shortly for an update. the sooner i become a paramedic and can use 12 lead the better


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## Jersey (Feb 9, 2010)

An upside down lead II is usually never indicative of right axis deviation, but instead LEFT axis deviation

Think about how the ECG is reading the direction of the electrical impulses in the positive negative spectrum.

Heres a link to an ECG showing left axis deviation (LAD). Notice the negative QRS complex! 

http://www.fammed.wisc.edu/medstudent/pcc/ecg/images/fig30.jpg

On the flight team or on a ground based unit seeing a negative QRS complex in lead II is a DEFINITE indication to do a 12 lead. Usually if you're applying the monitor, you can also justify doing a 12 lead. We only apply a monitor when we feel that there may be cardiac compromise either present or possible, thus MOST of the time a 12 lead is very indicated. 

I had an elderly lady complaining of difficulty walking due to lead "weakness" no other complaints. A precautionary 12 lead showed a massive inferior infarction that went straight to the cath lab.

I personally believe that paramedics should have a physician level pathophys understanding and EMT's at least a medic level understanding of pathophys. Why not educate yourself? One of the most valuable books I ever purchased was Dale Dubin's Rapid interpretation of EKG's. You can find it for less than 20 bucks used on line.

Even if you're "only" an EMT you can use your knowledge to better understand the "whys" of what we do, and maybe pass along some cardiac knowledge to your partner who seems to need it very badly.


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## lightsandsirens5 (Feb 9, 2010)

Jersey said:


> An upside down lead II is usually never indicative of right axis deviation, but instead LEFT axis deviation
> 
> Think about how the ECG is reading the direction of the electrical impulses in the positive negative spectrum.
> 
> ...


 
Oh, ok. I gets it now. Thank you very much for the explanation.


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## dmawhorter (May 4, 2014)

Can't go wrong with having him get the 12 lead done just incase.


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