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