A-Fib in WPW

[Craig Alan Evans]

What is everyone doing for rapid A-Fib in WPW?

 

[KellyBracket]

Hassling my pharmacy to dust off the about-to-expire procainamide.
(With the caveat about electricity for unstable, of course)

 

[DrankTheKoolaid]

re

Never actually seen it in the field. We carry Verapamil for Afib which is contraindicated with WPW. Procainamide as I understand it can be used which we do carry. But if presented with a symptomatic patient with Afib/RVR + WPW in the field, they are being cardioverted.

 

[MasterIntubator]

The ones I have had, most were stable enough they could wait until the ED. Amiodarone is what they get in the ED, cardioversion is about all we can do in the field for unstable pt. Our diltiazem, metoprolol and adenosine are drugs we carry - but none we can give for WPW

 

[Handsome Robb]

Cardioversion is my our only option in the field but they would have to be pretty symptomatic to justify it unless we were way out on the fringes of our coverage area but even then I'd probably just put the pads on them and watch them closely for signs of deterioration. I supposed we could call for orders for amiodarone. The issue with calling for orders here is usually by the time we get a doc on the phone and get the orders we are at the hospital, could throw a rock at the hospital or could have been at the hospital if we hadn't doinked around on scene.

No procainamide here.

 

[KellyBracket]

Some new guidelines out there. Check out the 2011 AHA recommendations for A fib. Amio was relegated to a class IIb recommendation, while procainamide is a class I .

Some folks have gone so far as to describe the use of amiodarone in WPW/AF patients to be a "potentially dangerous myth!"

 

[MasterIntubator]

I noticed that from AHA... seems like it is not being used as much as it used to be. Depending on what ER doc you talk to, is what answer you will recieve. Such inconsistancy.....:glare:

 

[dmiracco]

wow, you sill carry calan on the truck? procanamide is the best choice currently, however we actually cangive diltiazem for it based on our medical director.

 

[DrankTheKoolaid]

re

Yeah currently here in California Cardizem is not in the Paramedic Scope. But word from my Medical Director is that it is coming in with the new Scope Changes here in California. We will be dropping Calan and replacing it. Though in defense of Verapamil It has always worked when I have given it, with no ill effects. Pretreatment with CA++ on the other hand scares the hell out of me, as I have had a patient react poorly to put it mildy to it.

 

[dmiracco]

Cardizem is an awesome medication that works well with afib with rvr, the major effect is hypotension which responds well to bolus.
Truth of it is that if you have an afib with rvr at a high rate you cant really tell if its wpw untik you get good reduction in the rate

 

[TomB]

Cardizem is an awesome medication that works well with afib with rvr, the major effect is hypotension which responds well to bolus.
Truth of it is that if you have an afib with rvr at a high rate you cant really tell if its wpw untik you get good reduction in the rate

That's not true. AF with RVR should not be in the 250-300 range and if it is you should strongly suspect an accessory pathway, particularly when the shortest R-R interval is 240 ms or less. In that case you could harm the patient with antiarrhythmics (including amiodarone). The only "safe" drug (note the scare quotes) is procainamide as others have mentioned, which is not a particularly easy drug to administer. In the prehospital setting? Leave it alone! If it's unambiguously hemodynamically unstable shock it.

Tom

 

[dmiracco]

I have seen wpw from 150-300 that wasnt seen until it was slowed down. remember rate alone does not justify the rhythm. I also disagree with "Leaving it Alone" as I have treated many patients that were pretty symptomatic due to the rate, due to preload, who discontinued all of the s/s post reduction. The advancement in modern day medicine as well as paramedicine has taken us to assess better and treat more than the way we used to just leave things alone. Now grant it that being to aggressive when it is not needed can cause harm but Im talking about patients that are symptomatic and will benefit treatment. Risk vs benefit, thats pretty much the question.

 

[Craig Alan Evans]

Cardizem is an awesome medication that works well with afib with rvr, the major effect is hypotension which responds well to bolus.
Truth of it is that if you have an afib with rvr at a high rate you cant really tell if its wpw untik you get good reduction in the rate

I disagree, afib with WPW has a distinct pattern and giving these patients a Ca blocker can cause VF.

 

[TomB]

I disagree, afib with WPW has a distinct pattern and giving these patients a Ca blocker can cause VF.

Exactly. It's contraindicated.

 

[Christopher]

...along with B-blockers and amiodarone and well pretty much anything but procainamide

Probably should be cardioverting these patients anyways.

 

[Doczilla]

IMHO, there's no "leaving it alone" when it comes to A-Fib/WPW. Other A-Fib circumstances, sure. You'll get 5 cardiologists saying 5 different things about how to manage A-fib, even stable RVR by itself. But add WPW to the mix, and they WILL decompensate if you don't cardiovert them.

Remember, the atrial rate in A-fib can be well above 250, and that bundle of kent can conduct almost all of that to the ventricles --- without the protective conduction-slowing effects of the AV-node.

And yeah, I agree with you guys, procanimide would be the only pharmacological option--- it's the only class I antiarrythmic that has calcium channel-blocking properties

 

[CCNRMedic1982]

Where I work we only have cardizem and lidocaine so if unstable cardio version is our best option. I would like to add a question. Per my protocols adenosine is contraindicated for wide complex a-fib and WPW. I was under the impression that adenosine was beneficial in pts with WPW? Is that just when assoc. with SVTs? Any thought would be appreciated.

 

[Christopher]

Where I work we only have cardizem and lidocaine so if unstable cardio version is our best option. I would like to add a question. Per my protocols adenosine is contraindicated for wide complex a-fib and WPW. I was under the impression that adenosine was beneficial in pts with WPW? Is that just when assoc. with SVTs? Any thought would be appreciated.

If it is irregularly irregular, adenosine is not going to be helpful and can be harmful. If it is regular, adenosine can be helpful.

In atrial fibrillation you have irregular chaotic impulses coming from all over the atria bombarding the AVN and accessory pathway. The AVN provides a buffer of sorts, slowing down the 400-800 impulses per second in atrial fibrillation from reaching the ventricles. However, without the AVN, atrial fibrillation will not get slowed down and can very likely lead to VF and cardiac arrest. Basically, the tachycardia is not dependent on the AVN.

In SVT and WPW, you have a circuit formed that is dependent on the AVN. There is not an automatic focus like in AF. Automatic foci need to be slowed down with antiarrhythmics or stopped with cardioversion, whereas circuits just need to be interrupted! So with adenosine, you interrupt the circuit in a regular rhythm like SVT with WPW (whether wide or narrow). Once you interrupt the circuit the tachycardia stops because it is dependent on the AVN.

I hope this helps!

 

[CCNRMedic1982]

Never heard it explained that way. It does help thanks.

 

[Fox800]

Amiodarone.