12 Lead ECG – Lead Placement Diagrams

On October 15, 2008, Lynne left me this comment:

I’m an EMT-B that just found your blog. My agency allows EMT-Bs to perform 12-leads prehospital, so that doctors and paramedics at the hospital have a printout to look at. Also, if our monitor sees an Acute MI or something critical going on with the heart, we know to hurry it up.

Do you have a 12-lead placement diagram? I’ve been taught where and so on and so forth, but after reading your blog, I’m betting you’d have a nifty diagram. I’m going to print it out and tuck it in my protocol book for reference.

Here are the diagrams you requested.

limb leads

precordial leads

Precordial lead placement with the V4 electrode in the position of V4R:


See also: Right Ventricular Infarction


See also Acute Inferior STEMI with Right Ventricular Infarction and Cardiac Arrest

From ABC of clinical electrocardiography – Acute myocardial infarction – Part 1. BMJ 2002; 324:831-834.

Right sided precordial leads

right sided
Posterior leads V7 (posterior axillary line), V8 (midscapular), and V9 (paraspinal)


Do you need comprehensive training in 12-lead ECG interpretation?

Check out our video-based 12-lead ECG course at ECG Medical Training!

Further Reading

Contiguous and reciprocal lead charts

ST-Segment Morphology

Right Ventricular Infarction

Guide to Understanding ECG Artifact


  • Cosmic Miami says:

    There is a decent fundamental explanation of electrode placement here, A good fundamental explanation here, http://www.mikecowley.co.uk/leads.htm#anchor764680And an interesting study here, http://ajcc.aacnjournals.org/cgi/content/abstract/6/6/457Personally, I take electrode placement seriously. In addition, it is important that serial 12-leads should be shot with the electrodes in the same location and with the patient in the same position be it sitting, supine, semi-fowlers, etc. Why? The anatomy changes based on the patient position. In order to properly compare serial 12-leads, the heart must be in the same location relative to the electrodes.

  • Anonymous says:

    I am a Respiratory Therapist RRT who does ekg’s on off shifts for cardiology. Have done ekgs for around 21 years. Our facility just started a STEMI program with goals for door to cath lab in less than 1 hour. I had 2 my last shift. Both were in cath lab in less than 40 minutes. I have been looking for additional info on ekgs especially r sided, have seen different variations (you have nice charts). I have tried to follow lead placement as exact as possible, however have seen others do leads on top of breast of well endowed females rather than lifting up the mass and placing leads underneath in proper fashion, also have seen v3-v6 all in straight row in 4 inch of chest space without even reaching near the midaxiallary line. Some leave patents upright, i always try to lay as flat as possible, but with some you just can;t get them supine due to pain or body habitus. You try to do the best with what you got and go from there. Thanks for the helpful site.~midnterrt

  • Anonymous says:

    Love your web page, the diagrams are awesome. I too am an RT with 20+ yrs of experience and in the last 5 yrs have been doing more and more “atypical” lead placement for rule outs. thx for the info.VENL8R@YAHOO.COM

  • this really bugs me. why on earth are people unable to follow these diagrams? there is pretty much only one way to place chest leads! (at least in men.) the next time i see v3 vertically below v2 and v4 vertically below v3 (very common at hospitals) i just may throw something at someone.

    and v1 and v2 are at the 4th intercostal space. FOURTH! not 3rd. not 2nd. not 5th. and no eyeballing! COUNT THEM WITH YOUR FINGERS! AAAARRRGGGHHH!!!

  • Nidal Ismail says:

    the diagrams show V1 V2 on 5th rib , while it should be in 2nd intercostal space

  • Nidal Ismail says:

    take back my comment

  • I agree with "burned out medic" – proper EKG placement is the key – too many people in our department have their own lead placement ideas, most of which are for their convenience, rather than following standard procedures

  • Phil says:

    Honestly lead placement is not that important… If it is at 3rd intercostal instead of 4th it still looks the same. V3 can’t be below V2 and V4 below that as that would obviously make a difference but then general “correct” area is fine. You can see elevation or depression either way. If you are a cardiologist or work for one and it must be “perfect” then it is what it is, but for the medic or anyone for that matter using EKG’s in an emergency setting it really does not matter.

  • Craig R says:

    What about lead placement for patients with dextrocardia?  Obviously we would use the right-sided precordial leads – but what about the limb leads?
    Do the different types of dextrocardia make a difference?

  • Paul says:

    To Phil:
    I work in an electrophysiology lab and most people here do not know the proper lead placement. However, anytime you are doing one "close" is not good enough. We may treat someone diferent based on differences in your "close" approximation of what hapened yesterday.
    If you are involved in patient care, please care enough to give them proper treatment when you know better.

  • Jkevin says:

    the precordial lead V3 lies on the 5th Rib? is it really placed superficial to the 5th rib? or it should be on 4th ICS or 5th ICS? My CI told me during my OSCE that V3 should be in lined with v4… but I shall contest that information and I need a rtionale or explanation…. Thank u very much… 

  • David Baumrind says:

    @Jkevin: V2 is placed in the fourth intercostal space… V4 is midclavicular, in the 5th intercostal space. V3 should be placed between V2 and V4, which is reflected in the diagram. Hope that helps!

  • sambo says:

    I work in A&E in UK, Diagram is correct and on top or below breast tissue is going to give the same result, below is easier to ensure the lead is correctly placed.
    Question, which 3 leads are moved to carry out posteria ecg, is it V1, V2 and V3 or V4, V5 and V6 ?

  • Sambo,

    If you place leads on top of adipose tissue, such as a breast, you'll get attenuation of the signals resulting in erroneously lower voltages.

    As for V7-V9, I like to move V4-V6; but really it is up to you. If your cables are not long enough to leave V1-V3 in place, I usually move the leads such that V1 becomes V4, V2 becomes V5, and so on, wrapping V4-V6's cables around to make V7-V9. That way when you print you have V4-V9 continuous.

  • sambo says:

    Hi Christopher,
    I completely agree in principle  with what your saying, however in order to widen my experience and knowledge, I have tried on top of tissue and beneath the tissue of the same person and found that the diffrences were either not detected or so small as to not effect the interpretation. All of our traces are requested at 40hz and I haven't tried the same test with higher freqeuncy which may show a greater difference.
    I usually leave V1-V3 in place and move V4-V6 around, however this opened up a debate with a student nurse who said she has been told that V1-V3 HAVE TO BE MOVED to where V4-V6 were  and then V7-V9 placed around the rear.

  • Cynthia Ystaas says:

    How morbidly obese people?  What is the best placement when there is so much adipose tissue/

  • Cynthia Ystaas says:

    How about photo of placement for Exercise treadmill?

  • john agho says:

    What’s the relationship btw lead I II and III and the heart.?

  • Archana says:

    if v1 &v2 leads place at 2nd intercostal space rather than at 4th intercostal space,is there any wrong will happen??

  • pamela mazzone says:

    Are the limb leads important in placement for a proper ekg?  I work with some nurses that place the limb leads on the waist area instead of the limbs for their convenience.  Am I wrong in encouraging them to place these leads on the lower limbs for a better ekg?

  • Medicsnl says:

    What really bothers me is the unprecise nature of the location for V3 in general. It appears if you get V2 and V4 correct, then V3 must be correct, right? Apparently not. Is there an anatomical position for V3 besides somewhere between V2 and V4?

  • sylvia says:

    V3 goes directly under the nipple (in a female, where the nipple would be if the breast were flat), and thus half-way in distance between V2 and V4.

  • Bonnie says:

    How do you do an ekg on someone who is in a fetal position?

    Thank you

  • Don says:

    Sylvia, the most common mistakes for landmarks of chest leads come from using the nipple as a landmark. The majoirity of female patients have breasts large enough so that the nipple will be in a different place depending upon the size and firmness of the breast, as well as her physical position. So, it simply cannot be used. It is very simple to use 4th intercostal space on each side of the sternum for v1 and v2, V4 can be determined quickly by tracing the next lower intercostal space (5) to the mid clavicular line, along the bottom crease of the breast against the chest wall. V3 goes between the
    v2 and v4 leads. As well, after attaching v4, you follow along the 5th intercostal space until you reach the mid axillary line, where you place v6. Then v5 goes directly in between v4 and v6. Using the nipple for landmarking on female patients with large breasts, as well as just putting a line of leads along the top of the breast with no way to know exactly where under that breast the ribs are simply because it ‘looks like it might be ok’, is simply the lazy man’s method of doing ekg’s, and I would not want anyone who worked that way taking care of any of my patients. I’m an RN and have been doing ekgs for 40 years. If anyone wants to challenge this information, read Jules Constant’s ‘Learning Electrocardiography’, generally considered the bible of ekg for the past 80 years. It’s easy reading and cheaply availabe used on amazon, as the information has never changed. Right sided ekg’s used to be standard, simply reversing the 6 chest leads onto the opposite side of the chest, but in the past 40 years some physicians only want some of the leads moved. As a picture tells a thousand words, I’ll leave it to this guy to show you where the posterior leads go http://resusreview.com/category/ecg/ If you want more exact, read Jules book. I hope this clears everything up.

  • cyn625 says:

    V3 is on the curve dead center of v2 and v4

  • Wayne says:

    I have been doing EKG’s for the past thirty years. It use to be that you always lay the patient in the supine position but here lately I have been told that with the patient sitting up right will not change the EKG, is this so ?

  • DR.VIJAYAN says:


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