Can someone please explain this ECG statement?

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Specializes in LTC, Cardiac.

Hello everyone, I recently got a job on a CMU and I am learning how to do ECG's. I read this statement about them and I'm a little confused by it, can someone please explain it?

To obtain a 12 lead ECG, four wires are attached to each limb and six wires are attached at different locations on the chest. The total of ten wires provides 12 views (12 leads)

I just dont understand how ten wires allows for 12 views. Any advice?

Thank you!:D

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Specializes in CTICU.

Because you have 10 physical leads on, but then you are looking from different angles.

Look up something called the Einthoven triangle, it shows how the leads are calculated.

For example, if you have leads on all limbs, 3 of the ECG "lead views" might be from RA->LA, LA->LL, and RA->LL. Then you can look from the limbs towards the heart. Then you add the chest leads (V1-V6).

Check out this page: http://library.med.utah.edu/kw/ecg/ecg_outline/Lesson1/lead_dia.html

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Specializes in home health, dialysis, others.

Only 2-3 leads are involved in any one particuler view. If you drew triangles involving 10 leads, you would get more than 12. Some are reverse views of the same lead. Do you have a good book on EKGs?

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Specializes in LTC, Cardiac.

I have ECG Notes by Davis, the one that fits in your pocket. Do you know of any other books?

Thank you both, I will check that website out

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Specializes in ED, CTSurg, IVTeam, Oncology.
Hello everyone, I recently got a job on a CMU and I am learning how to do ECG's. I read this statement about them and I'm a little confused by it, can someone please explain it?

To obtain a 12 lead ECG, four wires are attached to each limb and six wires are attached at different locations on the chest. The total of ten wires provides 12 views (12 leads)

I just dont understand how ten wires allows for 12 views. Any advice?

Thank you!:D

That's because the total 12 views are given by a combination of bipolar and unipolar leads. The Bipolar leads (RA, LA, LL, RL) produces views of I, II, III, AVR, AVL, AVF; while the unipolar leads produces V1-V6. Hence, the first 4 wires will give you six frontal views, and the next 6 wires will give you six horizontal views. Thus, 10 wires, 12 views.

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Specializes in Trauma ICU, Peds ICU.

I'm just going to add, in case it might be helpful, that the negative pole for the unipolar leads V1 through V6 is VW, or "Wilson's central terminal", calculated from leads I, II, and III. Quick and dirty explanation: It's a point at the center of the heart, towards which you are "looking" from any given V-lead.

I wasn't able to understand how a unipolar leads could work until someone told me that. So there are two poles, but only one of them is a physical lead that's attached to the patient.

If you really want to get tricky after this you can look up 15- and 18-lead ECGs (leads rV4 thru rV6 and V7 thru V9).

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Specializes in ICU.

Haha, it took me longer than I like to admit to figure out that "lead wires" are not the same thing as "leads." :)

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