EMCrit Wee: The Lewis Lead and a course in ECGs with Christopher Watford

The Lewis Lead (S5)

How to place the electrodes for the Lewis Lead (S5)

from Christopher Watford’s blog My Variables Only Have 6 Letters

S5 Lead: You can produce this using many variations of the electrodes, however, for simplicity’s sake we will stick with Kelly’s description:

  1. Place the Right Arm electrode on the patient’s manubrium.
  2. Place the Left Arm electrode on the 5th intercostal space, right sternal border.
  3. Place the Left Leg electrode on the right lower costal margin.
  4. Monitor Lead I.
Image from Paramedic Watford

Lewis Lead Enhances Atrial Activity Detection in Wide QRS Tachycardia

The Lewis Lead – Making Recognition of P Waves Easy During Wide QRS Complex Tachycardia

Christopher’s ideal path to learning ECGs if he had to do it all again

1. Structured Learning: Garcia and Holtz “12-Lead ECG: The Art of Interpretation

2. Depth of Knowledge: skip Dubin, get Chou’s/Goldman’s/Marriott’s (something with meat)

3. Deliberate Practice: read 1000’s of ECGs. Brady & Mattu “ECGs for the Emergency Physician“, Marriott’s “Challenging ECGs“, Harvard’s WaveMaven

4. Participate!

Structured Learning/Depth of Knowledge links:

http://library.med.utah.edu/kw/ecg/ (Alan E. Lindsay’s ECG Learning Center)


 CCTMC Conference

The Air Medical Physician Association is co-sponsoring an upcoming conference called CCTMC: Critical Care Transport Medicine Conference—info and brochure available here.

It’s 4.2.12 through 4.4.12 in Nashville.

This year’s opening talk at the conference, is “Upstairs Care Outside: Top Ten Tricks of the Trade for Bringing ICU-Level Care to the Transport Environment.”

And now on to the wee…

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  1. says

    Glad to be on the podcast, and thanks for the kind words!

    I should disclose that I’ve been an associate editor at the EMS 12-Lead blog for about a year now, so you can take that recommendation with a grain of salt 😉

  2. Mike Jasumback says

    I’ll have to try this. Back in the olden days (think Lifepack 3) We simply put RT arm lead on the sternum and the Lt leg lead on the back and set it for lead II. Looks directly through the atrium. I actually had to do this two nights ago to determine whether someone was in AF with slow RVR or 3rd degree heart block.

    Mike J.

    • says

      I’ll have to try the thru-the-chest look. I’ll post some 3-Leads that compare the two views. The nice thing with the thru-the-chest view is the ventricular vector like likely pointing away from it.

  3. Mike Jasumback says

    P.s. I second the recommendation for the CCTMC conference for those interested in out of hospital care. I’m speaking on Sepsis (so that’s probably a waste of your time) and the rest of the conference is phenomenal for state of the art transport medicine

    Mike J.

  4. Minh Le Cong says

    nice tip Chris! must try that one out. Do y really find it useful in the prehospital setting.?
    Love the idea of the opening talk for the air medical conference!

    • says

      To date I’ve used it twice: on a VT versus SVT versus PMT patient and a ST versus a slower Atrial Flutter patient. In the former it provided no additional data, in the latter it confirmed atrial flutter.

      If I use it in the field I will have completed a 12-Lead, tried doubling the gain and compared II, V1, and V6 on a long rhythm strip…if I’m still searching at that point I’ll place the Lewis Leads. I will admit I don’t hold strict to which two limb electrodes get chosen, you just have to remember which lead to view!

      • says

        i’ve now found a few cases of flutter, a 3rd degree block with p-waves that were indiscernible on 12 lead, and a sinus brady with BBB that looked like vent escape.

  5. Bill Hinckley says

    Scott, thanks for the shout! There’s no better clinical conference dedicated to transport medicine in the US than CCTMC. I’d love to see you there one of these years; until then, I’ll keep preaching the Emcrit gospel. Mike, I look forward to your sepsis talk! Chris, you taught me something completely new today. Thank you.

  6. says

    Christopher is far too humble to plug it heavily, so I’ll do it for him. The EMS 12-Lead Blog (Tom Bouthillet’s along with Christopher and David Baumrind) is probably the best single educational resource online for learning the ECG. It’s 100% free, diligently maintained, and exercises a depth and breadth that is valuable for every level of care. For developing a skill that remains very relevant, and yet is somewhat on the decline in healthcare today, I think it’s an invaluable resource and one of the best examples I know of what web-based education can do. I myself owe a huge amount of my understanding of the ECG to Tom et al., and know many others in a similar position. Their team continues to hammer away in the bitmines for no particular reward, so send some traffic their way and let’s take a moment to applaud them!

  7. Mike Sherriff says

    Chris has outlined an excellent path to ECG mastery, but I would also add to Structured Learning:

    Garcia and Miller’s “Arrhythmia recognition: the art of interpretation.”

    Where Garcia’s 12-lead book will really help with basic 12-lead interpretation, Garcia’s arrhythmia book will help one learn an “intermediate” level of rhythm interpretation. It addresses concepts in a straightforward, graphics rich, manner similar to his 12-lead book ; but goes beyond basic generalizations like SVT to teach AVNRT, AVRT, pacemaker rhythms, etc.

    I have to say Amal Mattu’s 2 books of ECG’s for the Emergency Physician really increased my comfort level. I did 4 ECG’s each morning after cleaning the ambulance (like my morning cross-words), and by the time I was halfway through the second book, I felt pretty strong!

    Another resource that I’ve just discovered is Dr. Sean Fox’s Academic Emergency Medicine Education Masters at mededmasters.com. Dr. Fox is from Carolina’s Medical Center and has a lot of great education on the site, but an absolute gem for us ECG nerds is located there: Short video ECG lessons by Amal Mattu!

    I’ll close by saying:
    It makes me proud that paramedics like Chris and Tom (and many others) are out there setting the bar high for prehospital medicine. As paramedics, we may very well be the last person to read the patient’s ECG before they die, so we should know what we are looking for!


  8. says

    Great segment Scott. And great ECG nuggets Chris and Mike. Now I have two third options after increasing the paper rate and gain. Thanks for all the ECG resources – I’ve been looking for a way to brush up and I’ll be passing them on to all our trainees.

  9. Paul Catum says

    One more resource for you: one of our EM residents pointed me to this site, http://www.emedu.org/ecg/
    which has some good markups of various conditions. There is a Quiz function on the site which is quite useful.



  1. […] tillfälligt mer blockerat, SVT kan terminera helt och sinustaky går långsammare). Esofagus-EKG. Lewis lead. Titta gärna på frekvens över tid som hjälp (sinustaky varierar, SVT och fladder helt […]

  2. […] tillfälligt mer blockerat, SVT kan terminera helt och sinustaky går långsammare). Esofagus-EKG. Lewis lead. Titta gärna på frekvens över tid som hjälp (sinustaky varierar, SVT och fladder helt […]

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