Chemical or Electrical Cardioversion?

[E tank]

I suppose you ask about SVT and WPW as to whether or not adenosine would work? I guess it would depend on whether or not the aberrant pathways are susceptible.

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No, I ask because of missing that diagnosis and giving a CCB (or really anything that inhibits A-V node conduction) risks inducing a non-perfusing ventricular rhythm. That's what the science says and I was wondering if there was any real world experience with that here.

 

[Eden]

This brings up an interesting point...anyone have any actual experience with an SVT with a diagnosed or undiagnosed WPW? Maybe one that you picked up on?

I didn't run into one yet. Definitely something you want to make sure before administering a ccb.

 

[Carlos Danger]

No, I ask because of missing that diagnosis and giving a CCB (or really anything that inhibits A-V node conduction) risks inducing a non-perfusing ventricular rhythm. That's what the science says and I was wondering if there was any real world experience with that here.

Isn't that only in WPW with AF? I think normal WPW with retrograde conduction, node blockers are safe and effective.

 

[E tank]

Isn't that only in WPW with AF? I think normal WPW with retrograde conduction, node blockers are safe and effective.

Yep... you're right. A fast irregular rhythm sometimes takes a closer look to be sure. Just looking for folks' experience.

 

[Carlos Danger]

Yep... you're right. A fast irregular rhythm sometimes takes a closer look to be sure. Just looking for folks' experience.

Certainly not something I have experience with, just recalling what I've read.

 

[MackTheKnife]

No, I ask because of missing that diagnosis and giving a CCB (or really anything that inhibits A-V node conduction) risks inducing a non-perfusing ventricular rhythm. That's what the science says and I was wondering if there was any real world experience with that here.

With an SVT that is actually WPW, how would you know? You wouldn't see a Delta wave with the tachycardia. Adenosine blocks AV node conduction temporarily. I ask whether or not it has an effect on the aberrant pathways associated with WPW.

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[E tank]

With an SVT that is actually WPW, how would you know?

Right. Even with a "wide complex" tachycardia. Thats the question. I'm asking for folks' experience with it. Doesn't sound like the question is too common in day to day practice. One of those things you read about more than seeing.

 

[Tigger]

Right. Even with a "wide complex" tachycardia. Thats the question. I'm asking for folks' experience with it. Doesn't sound like the question is too common in day to day practice. One of those things you read about more than seeing.

I think it is still worth looking for delta waves in tachycardia. There is also some question as to whether or not adenosine is safe in WPW either. Most of the research I've found seems to indicate that it is safe however one of the medical directors is staunchly against. Not to mention a patient that we induced V-tach with. She was in a narrow complex SVT at 180 and in retrospect the delta waves were more than visible though I am not sure I would not do the same thing again.

 

[VFlutter]

I have seen A fib w/ WPW go into VF after verapamil. Also have seen 1:1 A flutter eventually degrade into VF.

 

[E tank]

I think it is still worth looking for delta waves in tachycardia. There is also some question as to whether or not adenosine is safe in WPW either. Most of the research I've found seems to indicate that it is safe however one of the medical directors is staunchly against. Not to mention a patient that we induced V-tach with. She was in a narrow complex SVT at 180 and in retrospect the delta waves were more than visible though I am not sure I would not do the same thing again.

I agree. Presumably, the delta wave contributes to the wider qrs. but depending on the morphology, like someone noted, it may not be really apparent without a closer look.

 

[E tank]

I have seen A fib w/ WPW go into VF after verapamil..

Wow...could you share the details?

 

[Eden]

I have seen A fib w/ WPW go into VF after verapamil. Also have seen 1:1 A flutter eventually degrade into VF.

I've had a patient go to vt and self cardiovert to sinus in 2-3 minutes. She didnt feel it at all. But she didnt have a known accesory pathway.

 

[Tigger]

I have seen A fib w/ WPW go into VF after verapamil. Also have seen 1:1 A flutter eventually degrade into VF.

I think CCBs are pretty big no no in Afib WPW. If you block or slow AV nodal conduction, the accessory pathway is going to receive all those impulses and block none of them, which will (as stated) induce VF. Or at least that's how I came to figure it.

 

[TomB]

I wrote a 2-part series on WPW. Part 1 looks at delta waves and Part 2 looks at the arrhythmias of WPW.

Part 1: https://www.ecgmedicaltraining.com/wolff-parkinson-white-wpw-syndrome-part-1/
Part 1: https://www.ecgmedicaltraining.com/wolff-parkinson-white-syndrome-part-2/

Realistically, orthodromic AVRT looks like SVT and antidromic AVRT looks like VT.

Tom

 

[VFlutter]

Wow...could you share the details?

It was a patient being flown in from an outside hospital. A fib RVR with bursts into the 200s. Polymorphic irregular beats with clear pre-excitation. Flight crew decided to give verapamil. Apparently sustained 250+ for a short time then went into VF and resuscitated. Strips were pretty impressive. Patient ended up on procanimide then ablation.