Posted by: medicblog999 | August 30, 2009

ECG Geek 4 – The diagnosis!

Well here is the answer…..But just in case you havent had a go yet, or you want to have one last look at the ECG before I reveal all, click here, then here, then come back to this post.

All done?  Good, lets get started!

I apologise in advance to those who know what I am talking about, but I am assuming that not all of my readers have a working knowledge of fairly advanced ECG interpretation, therefore I am going to do a little bit of teaching with this one.

So here is my thought process for this ECG:

File1-final ECG4 arrows

At first glance, I initially thought it was a third degree block. The widened QRS complex`s (The red arrow) were obviously ventricular in origin and coming at the slow rate that you could expect from a ventricular escape rhythm. However, when I looked closer I couldn’t see any P waves, therefore I cannot distinguish if there is any correlation between P waves and QRS complex`s. Is the because of AF? again, unsure as there was artifact, but there was something else that needed investigating first…..

Next I moved onto the funny little squibble before the ventricular beat (The blue arrow). That certainly doesn’t look like a P wave, but more like a low voltage RSR wave followed by a small T wave (The yellow arrow). If that’s the case, then we are looking at a normal beat, ectopic beat…..normal beat, ectopic beat – therefore its a ventricular bigeminy with a background bradycardia. Once you look at the blue arrows as the patients background rhythm you can then scan ahead and see that it is irregularly irregular, therefore the classic definition of AF comes to the front:

“any irregularly irregular rhythm with no discernable P waves is AF”

What some of you have been calling a missed beat (the green arrow), is actually where the bigeminal ectopic would be, but it just hasnt come in after that particular RSR complex.

So put them all together and you have an absolute bradycardic AF with ventricular bigeminy.

Ta da!!!

That doesn’t however, explain how a elderly gentleman can tolerate such a bradycardia. Amazing!

Congratulations go out to SJMedic who got the correct diagnosis from the first ECG!! – Clever clogs!

I also tend to agree with TOTWTYTR in his comment:

“What’s important is not the rhythm per se. It’s how the patient presents to you”

This is very much a ‘nice to know’ rather than a ‘need to know’. As long as who ever turns up for this gentleman recognised his severe bradycardia and acted on their findings, then he would be treated appropriately.

I checked up on him in the hospital a couple of days later and had a chat with the consultant looking after him who confirmed my diagnosis of the ECG, and informed me that the plan is for him to be fitted with an internal pacemaker as soon as possible.

Told you it was a good one!!

SJMedic, here is your Mars Bar!! :


I have really enjoyed doing this. If any of you have any interesting ECGs that you want to share with my readers, why not scan and email them to me at, with a little history of the patient (all identifiable details changed please) and I will post them so we can all learn something from each other.

Just an idea!


  1. I’ve been racking my brains about this all day at work questioning what I had seen, was coming back to have another look only to see that you had posted the answer already.

    Looks like I’ll be getting the cardiology books back out, knew I should have paid more attention in cardiology lectures!

  2. This was great fun! I’d love to see some more, and I’ll certainly be sending you any interesting ones I come across 🙂

  3. never would have guessed that was a t-wave after the squiggley bit. Thats it, thanks to you Mark Im now going to be a cashier for Tesco’s……I blow…LOL

  4. that was gonna be my 2nd guess….. 🙂

  5. Dang it, and I’ve always thought I was good at rhythms… and that one threw me. Dang it.

    Did I mention “dang it”?

    Great strip bud, next time I’ll get it right off. I’m sure.

  6. I’m sticking by my comment that they aren’t PVCs, they are Ventricular Escape Beats. The difference is subtel, but it can be important. In ACLS classes, it’s common for students to want to give Lidocaine for to treat the “PVCs”. Or at least it was when PVCs were treated more aggressively.

    Still, it’s important to understand that not all wide QRS complexes are premature.

  7. I still don’t know……….maybe those wide QRS’s are Sinus (there is a wave in front of each one. What you’re calling a T.) with an IVCD and then the little squiggly QRS’s are junctional escape beats due to sinus arrest ???????
    But I’m sure the damn cardiologist is right ! Know-it-alls !

  8. An IVR should be regular, but as you point out , there are some complexes which don’t have FLBs with them. True bigeminy should have no missed FLBs either. So, we’re in a bit of a quandary as to what they really are.

    Still, the way I learned it is that if the intrinsic rate is slow and the FLB comes later than you expect it, then it’s escape, not PVC. Look also at the distance between what I am calling the T wave and the FLB. I think that might also be a clue.

    What would be interesting would be to see what would happen if you could externally pace the patient. If the beats went away, it’s more likley that they were escape.

    All of which is sort of like rearranging deck chairs on the Titanic. If the patient is symptomatic, then you need to treat him. If he’s not and appears stable, monitor him, transport, and be on guard for deterioration.

    The end game is to not F up the patient under the guise of trying to “fix” a problem that doesn’t need acute fixing.

    Remember, “Don’t just do something, stand there.”

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