What do you think of this 12-lead? ***UPDATED

Without any details to accompany this tracing, what do you think?

(Hint: You probably won’t see too many similar strips at Prehospital 12-Lead ECG Blog or Dr. Smith’s ECG Blog, the two blogs on this subject that I visit the most.)



Thanks for all the responses. Reading through them, there are different opinions regarding this tracing.

I wasn’t sure if I wanted to post this relatively boring tracing in the first place, since the other blogs (ahem, Tom) always have way more exciting cases, but based on the feedback, it seems that we can have a worthwhile discussion about it. I’ll try to make it so you don’t feel like you’re wasting your time.

Let’s take a look at some of the boring technical stuff:

Rhythm: Normal sinus.

Rate: 67, regular.

P waves: Present, all the same shape.

PR: 0.154 s, constant, 1 P wave per QRS complex.

QRS: 0.104 s, constant, not quite at the 0.12 s cutoff that is generally used for BBB/IVCD. (Be sure to apply the full interval across ALL 12 of the leads, or you’ll mistake the terminal part of the QRS for ST-deviation, such as aVR in this case. It can also help measure J-points.)

QT: 0.368 s

QTc: 0.388 s

Lead placement: It doesn’t stick out to me as incorrect.

Frontal axis: Normal quadrant, probably closer to 90° than 0°.

Z axis: 50° posterior, which is a bit more posterior than normal, and possibly why I and aVF are both nearly isoelectric at the same time. (Picture this in 3-D space.)

Hypertrophy: R in V2 (22mm) + S in V5 (12mm) = 34mm, not quite at the 35mm cutoff that is generally used for LVH, but close. Anyway, it’s not a yes-or-no, hard cutoff.

U waves: Present in V1-V4. Seen in many cases, including LVH.

R-wave progression: Other than the late transition from negative to positive, it looks fairly normal to me without notable loss of amplitude. LBBB typically has poor R-wave progression in V1-V4, and so does anterior MI.

T-wave discordance: No lead really sticks out as abnormal. In any case, experts (not me) don’t really agree on which part of the QRS – terminal or dominant deflection – to use to determine T-wave concordance/discordance. I think it’s more of a pattern recognition thing; I just kind of know when I look at it.

Ischemia/infarction: The precordial T waves are fairly large, so are they hyperacute in the setting of an anterior MI? The J-point is mostly fuzzy, so there is arguably ST-depression in I, II, III, aVF and V6. There is ST-elevation in aVL and V1-V4. Along with the T waves, is this significant? How do we even measure the J-point? What to do?

This is why EKG interpretation remains, for the most part when it comes to crucial decisions, more of an art than a science. A lot of this goes back to pattern recognition, which only comes with looking at a lot of 12-leads. Some may say the concavity in V2-V4 is likely benign, possibly due to early repolarization. As different commenters pointed out, there are a number of things that may or may not be wrong with this tracing. I’d like to tell you that it goes without saying that the patient’s presentation and a thorough history are very important, but I keep running into crews who activate cath labs for 25-year-olds with toe pain. It also helps immensely if we have old EKGs for comparison. Of course, in the pre-hospital setting, we don’t usually have a lot of those lying around.

Well, fortunately, I happen to have a 12-lead of the same person from 2007.

With the exception of a few tenths of a millivolt in a couple of precordial leads, this tracing is pretty much the same as the one from 4 years ago.

Both tracings were obtained at routine medical exams administered by the person’s employer. Both were done properly – correct lead placement and connections – by the same provider.

One of the things I’ve slowly learned over the years is that while it’s sometimes difficult to identify badness on a 12-lead, it’s even more difficult to tell yourself to stand down and relax.

So, does this mean that these 12-leads show significant pathologies?

I don’t think so. I know it’s not a picture-perfect tracing, the ones you see when you Google “normal EKG,” but everything about human beings has a wide range of (usually) normal variants. In addition to normal variants, there are countless unhealthy people with normal baseline tracings. This is what makes things so difficult sometimes.

I think these tracings are fairly close to normal, for the most part. I know this because I feel pretty healthy.

28 thoughts on “What do you think of this 12-lead? ***UPDATED”

  1. The QRS is misleading as it appears to be broad, but is actually not widened.

    The everything else looks fine except for the ST-segment of V2-V4, which may be elevated >2mm when one measures the ST-segment exactly between the S wave and start of the T wave.

    Should associated signs and symptoms of an AMI be present, I would probably treat for STEMI, but I would prefer a second opinion.

    1. there’s incomplete left bundle branch block
      when we have LBBB we don’t diabnose ischemia or infarction

      1. We certainly can diagnose ischemia and/or infarction in the setting of LBBB as long as we take into account what is or isn’t the expected ST/T-wave abnormalities. Sgarbossa, Sylvester, and Smith all have criteria to help us discern whether the ST/T-wave changes we are seeing in the presence of LBBB are ischemia or infarct related. However, to your point, none are present in this tracing.

  2. I looked at the 12-lead before reading your post. Tried to find something wrong with it…LOL you got me

  3. Sinus rhythm without ectopy ~65 bpm, PRi 0.18, QRSd of 0.10, QTc of 410ms. aVL is concerning with a qr complex and ST-elevation. The inferior leads have subtle ST-depression, most visible in III. The precordials display some U-waves, a poor R-wave progression, and peaking in the T-waves.

    A cold read would have me saying STEMI.

  4. This pt is presenting with Sinus Rythm as well as Left Ventricular Hypertrophy and show prolonged T waves indicating Hypocalcemia. Since LVH is present, the possible elevations are thought to be benign.

  5. Because the Medic is burned out, the ECG limb leads are placed on the wrong limbs, as evidenced by Leads AVR, AVL.

  6. At first glance, without knowing anything about the patient and presuming the medic and or his partner check for limb lead placement and proper precordial lead placement, I’d say sinus rhythm with early benign repolarization or borderline criteria for LVH…QRS is a little wide and shows possible fascicular block however, so really would depend on age, hx, current presentation and the rest of the patient’s vitals. Would I be rushing to a STEMI center based on this 12 lead alone…probably not.

  7. FLBs, all the way.

    Actually, without further information, NSR. I don’t see this limb lead reversal considering that lead I has a positive P and positive QRS, and no right axis deviation. Lead III is NOT depressed.

    It might meet criteria for LVH, but criteria =! diagnosis. Probably normal variant. Thin chest wall is most likely the case without further information.

    My differential? Normal ECG.

  8. Is it a LBBB if the QRS is not widened beyond 0.11 seconds? Also, the T-waves are all concordant in I, V6 and V1. So is this still a LBBB as many suggested?

    Further, would anyone mind clarifying how one goes about correctly measuring the ST-segment height in V2-V4?

  9. “I think these tracings are fairly close to normal, for the most part. I know this because I feel pretty healthy.”

    Famous last words !

  10. Just for you, I’d run you in lights and sirens, telling my driver to, “blow all the lights, this is the REAL DEAL!” Maybe board and collar you for good measure. You know, let you see the awesomeness of EMS.

  11. Well done! They all seem to be missing the point that this is YOUR 12-lead.
    Every year, it never fails. One of my medic students comes running up to me showing me a 12-lead and asking, “am I going to die?”.

    In the spirit of the company it keeps…..the story it tells…….and basic rhythm recognition, I salute you.

  12. I have been away from EMS to many years to remember everything about EKG’s but it seems to me that paramedics have to be doctors now. God bless all of you that have to learn all the things you need to know now. We really do appreciate yall.

  13. I know a few medics who would get all wet and excited about this pretty normal ECG, but absent something in the H&P that makes me think cardiac, I’d say it’s a pretty normal looking ECG.

    Remember, in EMS it’s important to remember that sometimes we have to resist the urge to do something and not just stand there.

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