# Synchronized Cardioversion - What happened?



## Christopher (Jul 26, 2012)

Here is an interesting case which came across my desk that I'd like to share, the full details of which will be in a post on my blog shortly:


> EMS was dispatched for a 62 year old male with an altered mental status. Upon their arrival they found the patient to be non-communicative, responsive to verbal stimuli, in moderate respiratory distress, with pale, diaphoretic skin, and weakly palpable radial pulses.
> 
> A 12-Lead ECG was obtained, showing a wide complex tachycardia with left axis deviation. It was interpreted by the paramedic as Ventricular Tachycardia.
> 
> ...



Printed summary of synchronized cardioversion (click for _mega-res_):




So what do you think happened next?


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## nocoderob (Jul 26, 2012)

He sync'd that??


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## DrankTheKoolaid (Jul 26, 2012)

Please, Please, Please say he didnt cardiovert that


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## Christopher (Jul 26, 2012)

Had multiple bouts of VT prehospital and inhospital. This is only the strip from the cardioversion. Only going off what I've got


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## fast65 (Jul 26, 2012)




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## DrankTheKoolaid (Jul 26, 2012)

*re*

I so just jacked that image for my collection Fast


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## NYMedic828 (Jul 26, 2012)

I'm nowhere near the ECG reading level most of you are, is this issue here that it is terribly synced?


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## DrankTheKoolaid (Jul 26, 2012)

Looks like ST with a LBBB to me.

I would be more inclined to give rapid fluid challenges to increase his preload and to correct the suspected right heart failure by presentation.

But hey im no expert


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## NYMedic828 (Jul 26, 2012)

Corky said:


> Looks like ST with a LBBB to me.
> 
> I would be more inclined to give rapid fluid challenges to increase his preload and to correct the suspected right heart failure by presentation.
> 
> But hey im no expert



How do we distinguish VT from LBBB? It's still a wide complex tachycardia?

Are we assuming left anterior fasicular blockage to rule in LBBB?

(not asking to criticize, asking because I don't know)


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## DrankTheKoolaid (Jul 26, 2012)

While it is a wide complex tach by definition.  Sometimes you have to dig deeper and try to figure out what came first the chicken or the egg.  Is this patient symptomatic because of the " wide complex tach " or is he compensating by becoming tachycardic in response to the insult, which is my suspision based on the into given and the presentation of leads II, III and aVf.

Im not skilled enough to use just II, III, aVf to differentiate them.  

History of cardiac coupled with his age and diabetes points towards and exisiting LBBB and not a VT


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## Christopher (Jul 26, 2012)

Corky said:


> While it is a wide complex tach by definition.  Sometimes you have to dig deeper and try to figure out what came first the chicken or the egg.  Is this patient symptomatic because of the " wide complex tach " or is he compensating by becoming tachycardic in response to the insult, which is my suspision based on the into given and the presentation of leads II, III and aVf.
> 
> Im not skilled enough to use just II, III, aVf to differentiate them.
> 
> History of cardiac coupled with his age and diabetes points towards and exisiting LBBB and not a VT



I've intentionally left this ECG vague as the rhythm itself is not quite the important message. For those interested, the 12-Lead I would say is either 2:1 atrial flutter or ST w/ a really long 1AVB. My retrospectoscope would have done adenosine first, but I don't know anything really about the patient.


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## Handsome Robb (Jul 26, 2012)

Christopher said:


> I've intentionally left this ECG vague as the rhythm itself is not quite the important message. For those interested, the 12-Lead I would say is either 2:1 atrial flutter or ST w/ a really long 1AVB. My retrospectoscope would have done adenosine first, but I don't know anything really about the patient.



Wondering why on the adenosine? Not saying your wrong just wondering. Doesn't seem fast enough to be SVT. I agree with ST with a LBBB. Fluids and a quick ride seem like the way to go here plus that does not look like it's synced properly. Was he complaining of anything prior to this episode?


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## DrankTheKoolaid (Jul 26, 2012)

Because adenosine is an acceptable treatment per latest AHA guidelines for undifferentiated wide complex tachycardia, would be my guess


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## Christopher (Jul 26, 2012)

NVRob said:


> Wondering why on the adenosine? Not saying your wrong just wondering. Doesn't seem fast enough to be SVT. I agree with ST with a LBBB. Fluids and a quick ride seem like the way to go here plus that does not look like it's synced properly. Was he complaining of anything prior to this episode?




"Altered mental status". Had runs of "VT" in the ED.

Otherwise no idea, not my patient, just a rate ~150 in a patient with prior cardiac (could be AFib, could be CABG/stent, I don't know which) usually dings my atrial flutter bell. Fluid, adenosine...but hell I'd have to see the patient to determine if I'd shock (likely just ride it in).


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## NYMedic828 (Jul 26, 2012)

Christopher said:


> "Altered mental status". Had runs of "VT" in the ED.
> 
> Otherwise no idea, not my patient, just a rate ~150 in a patient with prior cardiac (could be AFib, could be CABG/stent, I don't know which) usually dings my atrial flutter bell. Fluid, adenosine...but hell I'd have to see the patient to determine if I'd shock (likely just ride it in).



What was the outcome of their shock?


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## Smash (Jul 26, 2012)

What was his potassium?


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## fma08 (Jul 26, 2012)

It's not syncing the same for each complex, thus the sync function is not reading/working properly, thus you cannot perform a synchronized cardioversion. Treat as best you can w/o the electricity, heavy on the diesel bolus.

As stated, not my patient, wasn't there, just basing off of history given and one EKG strip.

Curious to know what happened/outcome of the patient.


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## firetender (Jul 27, 2012)

*Please forgive the nosey FOG!*

I'm not quite sure what's up here -- what's the main question? -- so please bear with my ignorance.

First, I'm not clear on WHY the cardioversion. Is it because his heart is galloping and showing a slow but steady drop in BP? Is it because the heart is going SO fast (for the patient) that it is suspected that it will give out or be further compromised?

Why the choice to cardiovert? Changes in vitals/status?

Second is where the hell did those "markers" come from? Is that the machine telling you when it's planning to discharge? 

To me, this is showing a few markers precisely at the vulnerable stage of the Lead III complex (comparing above with below). 

And if you're going to do a synchronized cardioversion, why wasn't the valsalva maneuver performed first (vagal stimulation) or carotid massage for that matter (less likely, but still). Whatever happened to starting with the basics and leading up to the big guns?

Maybe I just need more details.

At any rate, from what I saw, this patient seems to have been put at risk. Am I right? I'm particularly interested in this one because...

Somewhere in my scrapbook is my documentation of an UNsychronized cardioversion I did of an 160+ tachycardia lasting 1/2 hour (60 y.o. male).

YES, UNsychronized because my unit had a Lifepak 4 on it that day without a "synchronize" button on it! The Lifepak 5's had just come out. When the Doc on-duty told me to get ready to cardiovert, I looked for the button, realized we had the old model and tried to bow out (all this after valsalva, etc.). He wouldn't let me, had me tune the beeper for the complex to tone right at the top of the R segment (I hope I'm getting details right!) and said *"Hit him just before you hear the beep!"*


You can imagine the brown on the floor!

Anyhow, the guy converted (DON'T DO THIS AT HOME!!!) , but back on topic, I really want to know what happened with yours!


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## Handsome Robb (Jul 27, 2012)

Christopher said:


> "Altered mental status". Had runs of "VT" in the ED.
> 
> Otherwise no idea, not my patient, just a rate ~150 in a patient with prior cardiac (could be AFib, could be CABG/stent, I don't know which) usually dings my atrial flutter bell. Fluid, adenosine...but hell I'd have to see the patient to determine if I'd shock (likely just ride it in).



Wide and fast would push me towards amio rather than adenosine. I don't see cardioversion working here since the monitor isn't syncing properly. I don't really see atrial flutter in this strip but i'd like to see more of the 3/4 lead as well as a 12 lead before I ruled it out or ruled in VT and treated as such. I never really thought of your thought process but I like it, it does make sense. 

Smash brings up a good point with the question about potassium. That would definitely make sense, although I'd expect bradycardia rather than tachycardia but I'm definitely still very new at this.


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## Christopher (Jul 27, 2012)

NYMedic828 said:


> I'm nowhere near the ECG reading level most of you are, is this issue here that it is terribly synced?





fma08 said:


> It's not syncing the same for each complex, thus the sync function is not reading/working properly





firetender said:


> Second is where the hell did those "markers" come from? Is that the machine telling you when it's planning to discharge?
> 
> To me, this is showing a few markers precisely at the vulnerable stage of the Lead III complex (comparing above with below).



That was my biggest concern when reviewing this case. Apparently, from the cardiac monitor's screen it was not evident it was double and triple sensing the QRS complexes.

Subsequent rhythm change:




Full summary here.


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## NYMedic828 (Jul 27, 2012)

That must be one of the scariest occurrences of cardioversion I am thankful I have not had this happen to me.(essentially killing someone)  Granted if I notIced the horrible syncing with my essentially baseline knowledge of ECG interpretation, an experienced crew (assuming) should of picked up on it...

Truly lucky they were able to fix the problem and essentially save the patient from themselves. I get the feeling if the outcome had ultimately been the opposite, a storm would have followed.



So, in the end, can we determine if it was simply an SVT with wide aberrancy vs. vtach, LBBB w/ ST or atrial flutter? (how would we presume flutter anyway from this? I was curious about that before)

All I know is it's a wide complex tach, with leftward deviation suggesting an LBBB.


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## VFlutter (Jul 27, 2012)

Ahhh I'm too late, I was going to guess that the shock would send them into V-Fib.

Almost looks like what I see with pacemaker/AICD malfunctions.


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## Anjel (Jul 27, 2012)

Corky said:


> Because adenosine is an acceptable treatment per latest AHA guidelines for undifferentiated wide complex tachycardia, would be my guess



Any chance you have a source for that? I have been looking for the guidelines and can't find them.


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## Christopher (Jul 27, 2012)

NYMedic828 said:


> That must be one of the scariest occurrences of cardioversion I am thankful I have not had this happen to me.(essentially killing someone)  Granted if I notIced the horrible syncing with my essentially baseline knowledge of ECG interpretation, an experienced crew (assuming) should of picked up on it...
> 
> Truly lucky they were able to fix the problem and essentially save the patient from themselves. I get the feeling if the outcome had ultimately been the opposite, a storm would have followed.



I think this case, and a few others of inappropriate cardioversion, should teach you to print a strip to confirm the markers are being applied appropriately. Relying on what you see on the screen may not be appropriate!

I've got another case where cardioversion would have been incorrect, but the patient spontaneously converted.



NYMedic828 said:


> So, in the end, can we determine if it was simply an SVT with wide aberrancy vs. vtach, LBBB w/ ST or atrial flutter? (how would we presume flutter anyway from this? I was curious about that before)
> 
> All I know is it's a wide complex tach, with leftward deviation suggesting an LBBB.



Without a prior 12-Lead it would be tough to say for certain, but I think the 12-Lead in this case is suggestive of 2:1 atrial flutter or 1AVB and sinus tach given the morphology of the T-waves in V1.


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## Christopher (Jul 27, 2012)

Anjel1030 said:


> Any chance you have a source for that? I have been looking for the guidelines and can't find them.



From Part 8: Adult Advanced Cardiovascular Life Support:


> If the etiology of the [wide complex] rhythm cannot be determined, the rate is regular, and the QRS is monomorphic, recent evidence suggests that IV adenosine is relatively safe for both treatment and diagnosis47 (Class IIb, LOE B). However, adenosine should not be given for unstable or for irregular or polymorphic wide-complex tachycardias, as it may cause degeneration of the arrhythmia to VF (Class III, LOE C).


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## Anjel (Jul 27, 2012)

Thank you! 

Have these gone into effect? Because that's not what we are learning in school right now.


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## NYMedic828 (Jul 27, 2012)

Christopher said:


> I think this case, and a few others of inappropriate cardioversion, should teach you to print a strip to confirm the markers are being applied appropriately. Relying on what you see on the screen may not be appropriate!
> 
> I've got another case where cardioversion would have been incorrect, but the patient spontaneously converted.
> 
> ...



You would make a fantastic cardiologist if you ever decided to head back to the classroom.

Thanks for this and the other things you spend your time writing up.


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## Christopher (Jul 27, 2012)

Anjel1030 said:


> Thank you!
> 
> Have these gone into effect? Because that's not what we are learning in school right now.



I can't speak to your area's protocols, but ACLS since the 2010 updates teaches this. Our services have used adenosine as an option in WCT prior to the 2010 guidelines.


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## VirginiaEMT (Jul 27, 2012)

NVRob said:


> Wide and fast would push me towards amio rather than adenosine. I don't see cardioversion working here since the monitor isn't syncing properly. I don't really see atrial flutter in this strip but i'd like to see more of the 3/4 lead as well as a 12 lead before I ruled it out or ruled in VT and treated as such. I never really thought of your thought process but I like it, it does make sense.
> 
> Smash brings up a good point with the question about potassium. That would definitely make sense, although I'd expect bradycardia rather than tachycardia but I'm definitely still very new at this.



That would be my question. Why not a amiodarone drip at 150 mg over 10 minutes for this patient, followed by a maintenance infusion? It is my understanding that adenosine is only used in wide-complex tachycardia for diagnostic purposes only, is this correct? With this rhythm, if electricity was necessary why didn't the medic use a defibrillation dose instead of cardioverting considering it unstable and polymorphic?


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## Sublime (Jul 27, 2012)

I don't see how you can safely call that first rhythm strip ST with LBBB based on II, III and AVF. With a symptomatic pt. and that strip to go off I'd be leaning towards VT.

However in Christopher's blog the 12-lead clearly shows it is not VT. Guess this shows the importance of a 12-lead in diagnosing of VT.

Also, to my understanding of the story the crazy synch's that showed up on the strip were not present on the screen? How are you to prevent this from happening when to your knowledge the machine is working as intended? Sounds like a software issue that needs to be fixed.


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## DrankTheKoolaid (Jul 27, 2012)

Actually there are adenosine sensitive VT's.  Thats why the AHA guidelines changed to include it.  Im on my phone so to much of a pain to try to link something but if you google_fu AHA adenosine VT. You will see a ton of info on it

And yeah a full 12 lead would have been nice.  I was just playing with the info we had been given


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## Christopher (Jul 27, 2012)

Sublime said:


> Also, to my understanding of the story the crazy synch's that showed up on the strip were not present on the screen? How are you to prevent this from happening when to your knowledge the machine is working as intended? Sounds like a software issue that needs to be fixed.



I don't believe it was easily visible that the rate of sync markers didn't correspond to the rate of the QRS complexes. I've seen this before with sync cardio of afib, but in that case a lead change (to lead I) solved the problem.


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## NYMedic828 (Jul 27, 2012)

Couple questions.

In relation to the axis thread,

What is the best way to manually determine axis deviation on a strip like that? 

I figured since leads II, avF and avR all look pretty equiphasic, by actually counting the boxes it would seem avR wins which brings us to lead 3, which is predominantly negative, suggesting aprox -60?

And if I am correct on that, we would have left axis deviation, which could suggest left anterior fasicular block/ LBBB?



Second, I'm still not understanding how we reach the conclusion of a.flutter 2:1? What about the T wave suggests it specifically?


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## Christopher (Jul 27, 2012)

NYMedic828 said:


> Couple questions.
> 
> In relation to the axis thread,
> 
> What is the best way to manually determine axis deviation on a strip like that?



A strip like that one is not useful for determining axis. You need a perpendicular lead to help out  



NYMedic828 said:


> And if I am correct on that, we would have left axis deviation, which could suggest left anterior fasicular block/ LBBB?



Yeah the 12-Lead shows V1-negative morphology (given V6's morphology it is a non-specific intraventricular conduction defect...but that's not necessarily any different to us than LBBB).



NYMedic828 said:


> Second, I'm still not understanding how we reach the conclusion of a.flutter 2:1? What about the T wave suggests it specifically?



Anytime you have a regular rate of ~150 you should consider flutter.

Also, there is the Bix Rule, where if the P-waves (if they indeed exist) are circumscribed halfway inbetween the R-R you should suspect atrial flutter.

The T-wave suggests something other than just a T-wave due to their bizarre biphasic look.

My friend VinceD covers the flutter possibilities wonderfully in this blog post.

That being said, a strong case for sinus tach and 1AVB can be made  Isn't cardiology fun?


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## NYMedic828 (Jul 27, 2012)

:wacko:

In regards to decistion axis, wouldn't lead III be considered perpendicular to avR, which is the most equiphasic of the limb leads? If you can't use the 12 lead to determine it, how would you do it?


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## Aidey (Jul 27, 2012)

Because a flutter with a 2:1 conduction is usually around 150. 1:1 flutter is 300, 2:1 is 150, 3:1 75 etc.


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## Christopher (Jul 27, 2012)

NYMedic828 said:


> :wacko:
> 
> In regards to decistion axis, wouldn't lead III be considered perpendicular to avR, which is the most equiphasic of the limb leads? If you can't use the 12 lead to determine it, how would you do it?



I meant that the strip with II, III, and aVF are not useful without some other lead. I'd pick Lead I, but aVR and III are fine choices as well. It's a circle, so any two perpendicular leads help.

If you can't determine the axis in the frontal plane (i.e. all leads are equiphasic) then the heart is said to have an indeterminate frontal axis! In this case we know the depolarization of the ventricles is pointing directly towards either the dorsal or ventral aspect.


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## NYMedic828 (Jul 27, 2012)

I never even considered 1:1 flutter as possible.

I imagine that must be very rare. That essentially is just an EXTREME svt right? The AV node is allowing every re-entrant impulse through basically creating an uninterrupted circle?


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## Christopher (Jul 27, 2012)

NYMedic828 said:


> I never even considered 1:1 flutter as possible.
> 
> I imagine that must be very rare. That essentially is just an EXTREME svt right? The AV node is allowing every re-entrant impulse through basically creating an uninterrupted circle?



1:1 flutter in infants could likely use the AVN, however, in most other cases it requires an accessory pathway.

However, there is always more than one way to skin a cat! You can get 1:1 conduction of atrial flutter through the AVN in adults, you just have to think outside the box...by slowing the flutter rate without affecting the AVN (e.g. procainamide). The AVN can conduct at 200-230 no problem, but the ventricles sure find that to be bothersome.


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## Aidey (Jul 27, 2012)

I posted a case with 1:1 flutter in an adult a few months ago.


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## 18G (Jul 27, 2012)

The wide-QRS, really tall T-waves on the 12-lead and the history of renal failure goes ding, ding for hyperkalemia induced. I would have more than likely wanted to give calcium and be thinking about albuterol. 

It would be nice to know if this is a dialysis patient and if pt. has missed dialysis recently. Any way to find out what the patient's potassium was or find out what was causing this ECG?

Smash was the only one that mentioned about hyperkalemia. I'm mkinda surprised no one else suspected this as the cause based on the ECG and the PMH. 

Hyperkalemia can easily cause wide-complex tachycardia and VT. And with an ECG looking like that I would suspect a K+ of over 7.


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## firetender (Jul 28, 2012)

There are a couple of things I don't understand here.

My primary question is what's the deal with that monitor/defibrillator?

How on God's Green Earth did it interpret THREE places on each complex as possible targets? Not to mention that one was clearly right on the vulnerable phase if you compared lead II to Lead III.

Why didn't the medic recognize that yellow flag?

Are the machines designed to work off of Lead II and provide a multiplicity of choices? Does the medic have to choose which one to "go for"?

Is that a defective machine? (the monitor, not the medic!)

What do other users of that make and model need to know so this doesn't happen again.

Or has it been happening and nobody's talking?

Maybe our Mr. Physio-control can help enlighten us!

I've gone more in-depth on my BLOG.


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## Jon (Jul 30, 2012)

Christopher said:


> I don't believe it was easily visible that the rate of sync markers didn't correspond to the rate of the QRS complexes. I've seen this before with sync cardio of afib, but in that case a lead change (to lead I) solved the problem.



Christopher - Thanks for sharing this. Is there any possibility of equipment malfunction here? Or was it just that due to the nature of the wide complex with a bundle branch block.

Also - did the monitor rate fluctuate much more randomly than the Pt's rate?


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## Christopher (Jul 30, 2012)

Jon said:


> Christopher - Thanks for sharing this. Is there any possibility of equipment malfunction here? Or was it just that due to the nature of the wide complex with a bundle branch block.
> 
> Also - did the monitor rate fluctuate much more randomly than the Pt's rate?



I don't believe it was a malfunction as I've seen it before, it's just the way the ECG "looks" and the way the markers look when superimposed. If you don't remember to pay attention to that, you won't notice.

Perhaps the monitor rate was wavering as well, I'll ask if they noticed anything like that. Good thought!


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## epipusher (Aug 7, 2012)

18G brought up a very important question: Was the patient a dialysis patient, and if so, has the patient been going? For us,as him as well it seems, this leads to a very specific treatment path given the pmhx and the way the patient is presenting.


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## systemet (Aug 8, 2012)

Opinions:

* I don't see why people have issue with this being VT.  The 12-lead on the blog page looks suspicious for VT, there's even negative precordial concordance.

* VT can have any axis.  A VT originating low in the RV (and probably a few other places) is going to have a leftward axis.



firetender said:


> My primary question is what's the deal with that monitor/defibrillator?



It's oversensing.  It has an algorithm that's designed to enable it to mark the R waves.  This probably relies on seeing where the ECG complex makes an acute change in direction.  This monitor is sensing 3 R waves for each complex, inappropriately.

This may be a maintenance problem / defective unit, or it may be a fundamental limitation of the algorithm.

The machine displays where it's sensing with triangles, so that the medic can visually confirm that it's sensing appropriately.  In this case, the medic either chose not to do this, or did it carelessly, and assumed the machine had sensed correctly.

The appropriate action, had they determined that the sensing was inappropriate would be to select another lead, and see if that improved matters.




> Are the machines designed to work off of Lead II and provide a multiplicity of choices? Does the medic have to choose which one to "go for"?



The medic can choose.  The machine is usually fairly reliable, but as illustrated here, has its moments.



> Is that a defective machine? (the monitor, not the medic!)



Maybe, maybe not.  It would be interesting to know.



> What do other users of that make and model need to know so this doesn't happen again.



Assuming that the machine is working correctly, they need to be more diligent in checking that the machine is correctly labelling the R waves.

This "oversensing" can sometimes be a problem in implanted pacemakers, or AICDs.


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## Aidey (Aug 8, 2012)

Just because it is suspicious for V Tach doesn't mean it is V Tach. When you look at the rhythm present right after the v-fib it is obvious that the QRS is still wide, the T waves are still peaked and there is still discordance.


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## systemet (Aug 8, 2012)

Aidey said:


> Just because it is suspicious for V Tach doesn't mean it is V Tach.



Agreed. I can appreciate the argument that there may be F waves in aVR.  But VT seems a strong possibility, and I don't think that the 3 lead or the pre-12-lead really paint a picture where treating this as VT is wildly inappropriate.




> When you look at the rhythm present right after the v-fib it is obvious that the QRS is still wide, the T waves are still peaked and there is still discordance.



True, but we're also looking in paddles at 0.5-30 Hz, probably at lead II, in a stunned heart.  

When I referred to negative precordial concordance, what I meant was that, in V1-V6, the complexes were all negatively deflected.


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## Aidey (Aug 8, 2012)

Its ST with a LBBB. Most likely with elevated potassium. 

You've got RS complex present in V5 and V6 - Favors an SVT over VT.
The QRS complexes in V1-V6 appear to all be under 100msc - Favors an SVT over VT.
There is no evidence of ectopy or fusion beats - Favors an SVT over VT.
There is no slurred or notched S wave in V1 or V2 - Favors an SVT over VT.
No Q waves in V6 - Favors an SVT over VT.


Also concordance and discordance refer to the direction of the QRS vs the direction of the T wave. Concordance means they are both going in the same direction. Discordance means they are going in opposite direction. The term you are looking for is "deflection". The percordial leads have a negative deflection.


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## Christopher (Aug 8, 2012)

Aidey said:


> Also concordance and discordance refer to the direction of the QRS vs the direction of the T wave. Concordance means they are both going in the same direction. Discordance means they are going in opposite direction. The term you are looking for is "deflection". The percordial leads have a negative deflection.



In the case of SVT versus VT, the phrase "positive concordance" and "negative concordance" is referring to the polarity/deflection of the complexes, not the QRS/T-wave axis relationship.


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## Aidey (Aug 8, 2012)

Interesting. I have never in any EKG lecture heard it different than what I posted. It may be that our Doc is just simplifying it to avoid confusion.


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## Christopher (Aug 8, 2012)

Aidey said:


> Interesting. I have never in any EKG lecture heard it different than what I posted. It may be that our Doc is just simplifying it to avoid confusion.



This use/abuse of the term is limited to the discussion of VT versus SVT, but I understand your confusion. It is a relatively specific finding for VT which I've covered in a blog post detailing why its absence does not rule-out VT (not the case here).


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## systemet (Aug 8, 2012)

Christopher said:


> In the case of SVT versus VT, the phrase "positive concordance" and "negative concordance" is referring to the polarity/deflection of the complexes, not the QRS/T-wave axis relationship.



Although it looks like I'm in error here, and we don't have negative precordial concordance, As this would require the presence of QS complexes throughout the precordial leads.  The rS complexes in at least V5-V6 (and possibly V3, V4) make this impossible.

Somehow I'd turned QS waves throughout the precordium into "predominantly negative complexes across the precordium" in my head.  My fault.

Were we to have negative precordial concordance it would be highly specific for VT.


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## systemet (Aug 8, 2012)

Aidey said:


> You've got RS complex present in V5 and V6 - Favors an SVT over VT.



Yes.



> The QRS complexes in V1-V6 appear to all be under 100msc - Favors an SVT over VT.



Maybe.  Depends on where you put the J point.



> There is no evidence of ectopy or fusion beats - Favors an SVT over VT.



True, but very insensitive, especially off a 10 second strip.



> There is no slurred or notched S wave in V1 or V2 - Favors an SVT over VT.



Well, V2 looks notched to me, but I agree that there's a rapid downstroke to the nadir of the S wave, and no classic Josephson's sign.



> No Q waves in V6 - Favors an SVT over VT.



Yep.

You make a good case, and you're probably right, and I'm probably wrong.  But I think I'd still be reluctant to give metoprolol or diltiazem here.  These are difficult judgments to make in the field.


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## TomB (Aug 9, 2012)

Who says it requires QS complexes across the precordium?



systemet said:


> Although it looks like I'm in error here, and we don't have negative precordial concordance, As this would require the presence of QS complexes throughout the precordial leads.  The rS complexes in at least V5-V6 (and possibly V3, V4) make this impossible.
> 
> Somehow I'd turned QS waves throughout the precordium into "predominantly negative complexes across the precordium" in my head.  My fault.
> 
> Were we to have negative precordial concordance it would be highly specific for VT.


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## Aidey (Aug 9, 2012)

I don't think anyone is arguing for advanced pharmaceutical intervention at this point. As someone mentioned a fluid bolus would be one place to start. Since this is a dialysis pt we have the potential for some very whacky electrolyte levels contributing to this.


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## systemet (Aug 9, 2012)

TomB said:


> Who says it requires QS complexes across the precordium?



Perhaps a better way for me to have put it is "the absence of RS complexes across the precordium".

(Kusumoto, ECG Interpretation: From pathophysiology to clinical application, googlebooks: http://books.google.ca/books?id=wQ6...Bw#v=onepage&q=precordial concordance&f=false)

For what it's worth, I've read other sources that seem to contradict this.  Most of my books are in a storage container waiting to be shipped right now.

Also descibed on p.455, Irwin & Rippe's Intensive Care Manual, here:  http://books.google.ca/books?id=ooH...v=onepage&q=precordial concordance RS&f=false


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