What's the heart rhythm?

You are called to the residence of 85 year old male complaining of chest discomfort.

Note: The details of the history and clinical presentation have been lost.

The cardiac monitor is attached.

What's your interpretation of this ECG?

*** UPDATE ***

Some very interesting comments so far….

Let's see if a review of the 12 lead ECG changes anything.

You know you're in trouble when the interpretive statement requires a third column!


  • SoCal Medic says:

    Where do you find these at? It is really hard to tell if there is a P wave with some of those complexes and if there are, they are of changing morpholofy, Irregular, Wide (QRS just long of .120) with different morphologies. It would be interesting to know if that lined up with his breathing, but I call it bad, ugly, and you can't get me to the hospital fast enough (I am at a loss honestly)

  • My first guess: -Atrial fibrillation with aberrancy, probably LBBB. Be weary of Fast Broad & Irregular rhythms though. -Single QRS looks to be coupled with a P wave. Since the QRS is of the same morphology as the rest I would count out PAC. -Pathological left axis deviation, LAFB.The first four complexes seem to share an RR interval You almost have a hyperkalemic Z fold pattern. The last two pairs of beats look to share a relationship, such as bigeminy. The varying QRS morphologies can be explained by alternans. With exception of the third to last and last complex; I believe they are from a different foci, probably ventricular. HR ranges from about 90 bpm to > 200 bpm. It may be reasonable to slow down this rhythm. If you deem it necessary to treat this rhythm, the WCT protocol wouldn't be out of the question. Click below:Link to response

  • SoCal Medic says:

    Adam,Damn impressive, thanks for the visual. In all honesty, I was thinking about heading down the WCT protocol, assuming his vitals warranted such a treatment. Part of what was throwing me was the rate as it sped up, and the changing morphology towards the end of the strip. The bigeminy makes sense, when you break the strip down. Just so many changes, sometimes you get that "oh what the hell is that." What is the hyperkalmeic Z fold pattern you mentioned?

  • Christopher says:

    EM guidemap – Hyperkalemia Gives some good samples of Z-fold and Dumping you could see in hyperkalemia.(prior post deleted as the link wasn't working)

  • Tom B says:

    Christopher -It's amazing what you can find when you start reviewing ECGs transmitted to the LIFENET! :)I agree with you. Fast and ugly! Tom

  • Tom B says:

    Adam – That is a fascinating analysis! Thank you for taking the time to mark up the ECG.You pointed out a couple of things I hadn't noticed.I wonder if a review of the 12 lead ECG will change your impression? :)Tom

  • Tom B says:

    C. Watford (I don't want to get the Christophers confused) – Your point is well taken that the history and presentation will dictate the treatment plan.Let us assume for the sake of discussion that the patient presents with classic signs and symptoms of ACS.Thanks for the link!Tom

  • Christopher says:

    With s/s of ACS and no allergies he'll get ASAx4, NTG pending BP, a line and maybe some fluid. 12L shows lateral and anterior elevation w/ recip changes inferior. Early STEMI notification for extensive anterior or anteriolateral MI. Another line because the cath lab will be happier. Morphine if some fluid and NTG don't help with the pain, but don't want to snow the fellow. Because it is "bad and ugly," I'm going to keep my eye on the pads and if fire was on scene, have one of them come along.As for my original interpretation, it appears the monitor disagrees that it is wide and the precordials concur. Narrow w/ some nasty injury/infarct patterns. I'm looking in V1 for some P-waves but I still don't see them, granted, P-waves are merely academic at this point…So new interp is sinus/sinus tach (b/c the monitor swears it see's p-waves) w/ bigeminal pvc's. Bad and ugly :-X

  • Tom B says:

    C. Watford – Nice catch! I hadn't noticed that the computer measured the QRS duration < 120 ms.Interesting….And wrong.Tom

  • Christopher says:
    • Rate: 100-250
    • Regularity: irregular
    • P's: not readily discernible
    • PR: not readily discernible
    • QRS: wide

    First three beats are regular, then the RR decreases before a run of irregular tachy complexes, so my rules are going to say a-fib w/ aberrancy. The end of the strip has obvious bigeminy though. PMHx and presentation will dictate plan of Rx.

  • After 12-Lead:Looks like the bigeminy continues. Difficult to say if the bigeminy is ventricular, but it seems to take over. The QRSd is much longer than the monitor thinks. Probably obscured by the interesting pattern. The bigeminy seems to end half way through the strip as indicated by the link at the bottom.There appears to be a RBBB with the QRS width and T-wave discordance making this a bifascicular block.Luckily, RBBBs don't distort ST segmentsin the same fashion as LBBBs. Extensive ST-elevation In Septal (v2), Anterior (V4), and all lateral leads with reciprocal ST-depression in the inferior leads. Possible posterior infarct indicated by ST-Depression in v1 and T-wave inversion in v1 & v2. I think it should be mentioned that the rate has slowed significantly. With the bigeminy leading to a slower rhythm, overdrive pacing should be considered. This isn't a paced morphology I have ever seen before. Patient Hx and presentation will determine that easily. I still don't see P waves, but it has become a moot point. This patient should receive expedited transport and care for ACS/STEMI.I did my best attempting to identify the J points and isoelectric line. Check out what I have done to your 12 Lead now Tom:Link

  • SoCal Medic:The "Z-Fold" pattern indicates severe hyperkalemia. The nadir of the S wave has a straight line to the top of a peaked T wave. Link to Z-Fold

  • Tom B says:

    Adam – Nice calipers! Your own invention? :)That's the first time I've heard to that referred to as the "Z-fold" pattern.I've always called the merging together of the S and T waves a "sine wave" ECG.But Z-fold works! :)Tom

  • Click Here for the calipers. I have the freeware version. My training captain(EKG Guru) showed them to me, and I had to get them… to solidify myself as an EKG nerd.Yea, sine wave is the same thing. Z-Fold sounds better to me, more audibly pleasing. I read it in some ECG book. I think Amatu's book.

  • This 12-Lead has also reminded me of some very interesting studies regarding left main coronary occlusions.ST-Elevation in aVR > v1 with RBBB, especially with LAFB and ST-depression in the inferior leads is highly specific for a left main coronary occlusion. You may have ST-elevation in aVL as well. Just a fun little fact for you. This 12-lead is very close to meeting the criteria. I believe v1 needs to be elevated with more elevation in aVR.

  • Adel says:

    irrigular irrigular rythm (VF) ,WITH aberrancy LBBB,ACS ANTERIO LATERAL MI

  • Simon G. says:

    hey guys…I do c p's but I think they're dissociated …the qtc indicates hyperk (as per Smith and Weingart), pathologic LAD (as per Dr wes and Tom B's graphic) with Acute MI (possibly high lat wall)…but I'm a FP intern, so I just watch you guys for the education…when you give the answer can you provide a brief explanation for this dense intern?

  • Simon G. says:

    just saw this was from 2009…

  • patrick says:

    Its  wide and irregular i am thinking its a-fib with rbbb also hyperk with possible stemi.   But my treatment would be if going if pt had cp and if vitals were ok i would go with iv asa nitro consider pain medication also o2. 

  • Dawn says:

    This is ugly, alright.  Those are ST elevations and depressions, not wide QRS complexes. The rhythm isn't the problem.  Sinus with PACs, most likely.  V2 through V6 and I and aVL have ST elevation:  probably left main occlusion.  II, III, avF, and V1 represent reciprocal depressions. I would treat as a STEMI alert, leave the rhythm alone.  Lots of diesel fuel, get to a cardiac cath lab. Do you have an outcome on the patient? Great ECG.   Dawn (RN, EMT-P, ECG Instructor, ER and Cath Lab Nurse)

  • Dawn says:

    I forgot to mention in my post, there is a Rt BBB, making the QRS a little wide.  BBB increases mortality in acute MI, so that's not a good thing.   The extreme Left axis deviation might be due to left vent hypertrophy or other causes.   Again, very interesting ECG, could be lots of other things going on, like hyperkalemia for example.  But the main problem right now is STEMI. Dawn

  • ectopic atrial rhythym with abberancy AND nonsustained V.TAchy.. ? digoxin Tox? HyperK

  • Andrew Przepioski says:

    Dawn, are you sure that's ST elevation & depression?
    To me, it looks like the QRS complex is merging with the T-waves making it look like there is ST elevation & depression.
    My initial thought looking at this ECG was irregular and wide, and atrial fibrillation with aberrancy came to my mind first.
    I don't think it really fits LBBB or RBBB. Althought V1 R/S > 1, I and V6 doesn't look typical for RBBB. I think this is IVCD from hyperkalemia.

  • tedbohne says:


  • Bruce Goldthwaite RP says:

    Atrial fibrillation with RVR and RBBB.

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