Interpret 12 lead ECG easily using these easy to remember tips. Locate Myocardial Infarction Accurately in all Areas. Lateral MI, Anterior MI, Posterior MI, Septal and Left Lateral wall MI.
I know – I know. 12 leads EKG remains one of those topics not so many nurses want to deal with. Learning how to read any 12 lead EKG presenting a myocardial infarction is a critical nursing skill every nurse should master.
This unbelievably easy way to interpret 12 lead EKG is only good for detecting the location of MI. In a future article, I will explain how to interpret conditions like cardiomegaly, right or left side congestive heart failure.
It is also important to understand basic arrhythmia interpretation which can all be seen on lead 2 of a 12 lead EKG sheet. See also detailed section of 12 lead ECG interpretation.
Are you ready to memorize these easy steps?
Step #1: Memorize all 12 Lead EKG Leads:
Get a plain piece of paper and write these leads numbers as they appear on the below diagram. The reason you are memorizing how to write them in this same sequence is because that is exactly how leads looks like on a 12 lead ECG paper.
Write these leads on a piece of paper as many times as it takes you to memorize this. You will be glad that you got this memorized because this is the first and most critical step to mastering 12 lead EKG interpretation for MI
To help you memorize these leads, notice leads I, II, and III follow each other in a vertical line on your left side.
Leads AVR, AVL & AVF comes next in the same sequence shown. To remember the correct sequence of the aV leads, remember this visual mnemonic.
The next two lines are taken by v leads from V1 to V6
Step#2 Highlight lead I and aVL:
Highlight lead I and aVL as shown in the diagram below followed by lead V5 & V6. These leads whenever showing ST elevation is indicative of Lateral MI but more about this in a minute.
Stay with me here
Step #3: Highlight/circle leads II, III and aVF
Remember the F stands for floor in our mnemonic above. Keep this between your fingers as well.
Step #4: Circle V1 & V2 leads as shown
Assume that is the mid-sagittal plane of the heart BUT the heart is not quite symmetrical as the left side is larger – remember?
Step #5: Join V3 & V4 leads as shown in the diagram below
Memorize this sequence over and over again until you can almost see this image with your eyes closed. Do it over and over again. Repetition is the mother of all skills. There is no better and easier way to address this elephant in the room called 12 lead EKG than memorizing this easy steps.
Step#6: Label all segments as shown below:
From here, watch this short video explanation over and over again. Trust me, if you only had 15-30 minutes, you will master 12 lead ECG interpretation and be able to locate where MI is occurring.
Notice that more than one highlighted areas could be elevated in a single EKG. This would show more than one area affected. This video is just to show you the basics of locating the affected areas of the heart.
Posterior wall MI, leads V1, V2 & V3 are depressed, NOT ELEVATED. Say that with me one more time J … v1-V3 are depressed.
Leave your comments and answer these two simple questions
- Where is MI occurring on this 12 lead ECG tracing?
- Where is the MI occurring in this EKG tracing?
See also, how to calculate mean arterial pressure MAP without memorizing the formula.
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I had a recent ekg done by my doctors medtech at their office.
She strated to put leads on me and stated there should be 12 leads but 4 were missing. She did the ekg with 8leads. But turned this ekg after the phycian assistant read it and it was abnormal. The dotor sighned off on it the next day. Is this a accurate ekg. The doctors billed my medicare im disabled as a 12 lead was done. Should this be reported to my medicare. Did I have a accurate ekg done.
This reply is a little late but its only called a 12 lead because in total it gives 12 views but there are not actually 12 wires. Kinda scary the medtech doesn’t know that. There are 10 wires total. 4 limb leads which go on each arm and each leg and then the 6 precordial leads which go across your chest starting in the middle and wrapping around to just under your left armpit. If you don’t get these 12 views the ecg isn’t great for diagnosing anything. However, if they were do take multiple ecgs and move the wires to cover the areas that had missing wires and note the modified placement on the ecg then that would be fine. Say they were missing the 2 closest to your armpit but took the ecg and then took the two wires off the middle of your chest and put them on those two spots that were missing the wire and then note on the ecg that they had to move the wires to compensate. Hope this makes sense 🙂
Great learning tool
1) Posterior Wall MI
2) Left Lateral MI
Thank you for the solid tips!
Thank you, Eric
Great review, thank you!!
This is so helpful!
Good job on details and visual cues. Very helpful
I have been looking for a simple, concise way to interpret a 12 lead EKG as an ICU NP. I just found it! Thank you for this!