Synchronized Cardioversion - What happened?

[NYMedic828]

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.

 

[VFlutter]

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.

 

[Anjel]

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.

 

[Christopher]

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.

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.

 

[Christopher]

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).

 

[Anjel]

Thank you!

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

 

[NYMedic828]

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.



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.

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.

 

[Christopher]

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.

 

[VirginiaEMT]

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?

 

[Sublime]

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.

 

[DrankTheKoolaid]

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

 

[Christopher]

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.

 

[NYMedic828]

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?

 

[Christopher]

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

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).

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?

 

[NYMedic828]

: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?

 

[Aidey]

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.

 

[Christopher]

: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.

 

[NYMedic828]

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?

 

[Christopher]

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.

 

[Aidey]

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