Afib vs Afib ala WPW

[pinipig523]

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So... I had another afibber tonight. No drama - just the usual cocktail of dilt 20 iv then dilt 30 po. Went to ICU stepdown after.

But I got to thinking, what about WPW that spurred an afib. You can't really give dilt or any nodal blocking agents.... and I know you're supposed to stick with something along procainamide (not sure about amio even).

So my question is - when you get a guy in afib, is there something you look for that makes you do a double take and really see if the guy is in wpw and give something other than the usual dilt cocktail?

My understanding is that WPW afib is usually VERY fast because of the accessory pathway - like afib with rvr in the near 200s. But what about QRS widening - do you guys go by this?

Thanks!

 

[Khaos]

I actually just saw a guy come in with afib with WPW 2 nights ago. Was a recent dx for him 6 months ago. Came in with wide QRS and a.fib at 240's. He was asymptomatic other than palpitations and said he felt lightheaded when he got up. Gave procainamide 1gm over 1 hr and at about 40 minutes he converted to sinus rhythm at 80. Worked like a charm. Admitted to cards, crit care time, and done. This was my first WPW at that rate. I've seen plenty of SVT but this was my first. Second first for me in 2 days...I just dx acute angle closure glaucoma the day before.

 

[Rendar5]

I see a lot of afib w/ RVR at my shop but I've only seen 2 patients with wpw afib. The wpw looked wide at first glance, like a vtach but irregular, but when you looked at the actual QRS complex, it only appeared wide because of the Delta wave.

The only reason I carry calipers in my bag at work. I'm not great at visually recognizing mild irregularity when it's so fast.

 

[WilcoWorld]

I had to read about this in at least 4 different texts before getting my head around it, but here's an attempt at a summary
-Orthodromic WPW can/should be treated like run of the mill tachyarhythmias without excessive worry. It looks different, but not ugly.
-Antidromic WPW-associated AVNRT is what we're all taught to worry about. Fortunately, this rhythm is ugly, and not something you're likely to be inclined to simply rate control.

Because a) It's always a good idea to shock unstable tachyarhythmias b) Procainamide works for stable v tach, antidromic WPW and a fib with RVR c) even the cardiologists perform pretty poorly when trying to use criteria to distinguish aberrant conduction from v tach...

-When in doubt treat as v tach.

Another pearl I learned was that your antidromic WPW patient is going to be the 28 year old who is talking to you about the fluttering in his chest, but the v tach is going to be the 50 yo who is diaphoretic and clutching his chest.

Hope that helps.

 

[docB]

I had to read about this in at least 4 different texts before getting my head around it, but here's an attempt at a summary
-Orthodromic WPW can/should be treated like run of the mill tachyarhythmias without excessive worry. It looks different, but not ugly.
-Antidromic WPW-associated AVNRT is what we're all taught to worry about. Fortunately, this rhythm is ugly, and not something you're likely to be inclined to simply rate control.

Because a) It's always a good idea to shock unstable tachyarhythmias b) Procainamide works for stable v tach, antidromic WPW and a fib with RVR c) even the cardiologists perform pretty poorly when trying to use criteria to distinguish aberrant conduction from v tach...

-When in doubt treat as v tach.

Another pearl I learned was that your antidromic WPW patient is going to be the 28 year old who is talking to you about the fluttering in his chest, but the v tach is going to be the 50 yo who is diaphoretic and clutching his chest.

Hope that helps.

👍This. For me it really boils down to wide vs. narrow. If it's narrow if it is WPW it's orthodromic so you can use the AV node to slow it down.

 

[turkeyjerky]

I had to read about this in at least 4 different texts before getting my head around it, but here's an attempt at a summary
-Orthodromic WPW can/should be treated like run of the mill tachyarhythmias without excessive worry. It looks different, but not ugly.
-Antidromic WPW-associated AVNRT is what we're all taught to worry about. Fortunately, this rhythm is ugly, and not something you're likely to be inclined to simply rate control.

Because a) It's always a good idea to shock unstable tachyarhythmias b) Procainamide works for stable v tach, antidromic WPW and a fib with RVR c) even the cardiologists perform pretty poorly when trying to use criteria to distinguish aberrant conduction from v tach...

-When in doubt treat as v tach.

Another pearl I learned was that your antidromic WPW patient is going to be the 28 year old who is talking to you about the fluttering in his chest, but the v tach is going to be the 50 yo who is diaphoretic and clutching his chest.

Hope that helps.

So my understanding was that no matter if it's orthodromic or antidromic, the conductance pattern is dependent on the AV node and you can use adenosine or a CCB to break it. The issue is only w/ Afib associated w/ WPW, where blocking the AV node could be disastrous and you need to either use procainamide or electricity. Stephan Smith has covered this in his blog.

 

[WilcoWorld]

So my understanding was that no matter if it's orthodromic or antidromic, the conductance pattern is dependent on the AV node and you can use adenosine or a CCB to break it. The issue is only w/ Afib associated w/ WPW, where blocking the AV node could be disastrous and you need to either use procainamide or electricity. Stephan Smith has covered this in his blog.

It looks like he's advocating for adenosine, but not CCB's. I agree that adenosine is safe in both anti and orthodromic cases, but that's for the same reason that it's "safe" in v tach - it's incredibly short acting. I also agree that a fib with antidromic conduction is the most concerning stable tachyarhythmia (and fortunately, the ugliest on ECG). However, I wont give CCB's to any of the antidromics (a fib or AVNRT), because both procainamide and electricity are options, and electricity is one of the safest drugs out there.

In short - don't worry about the slightly wide-QRS tachyarhythmias, because you can just do your usual stuff. And when in doubt, treating a WCT like v tach will be a safe choice.

 

[UnderwaterDoc]

So my understanding was that no matter if it's orthodromic or antidromic, the conductance pattern is dependent on the AV node and you can use adenosine or a CCB to break it. The issue is only w/ Afib associated w/ WPW, where blocking the AV node could be disastrous and you need to either use procainamide or electricity. Stephan Smith has covered this in his blog.

Yup, that's what I have been taught too. I just had a guy like this not too long ago, and had an extensive discussion with one of our cardiologists.

There is a small risk of making it faster with the Adenosine if it's antidromic, but since it is so short acting is not clinically significant. The guy I had we hit with the Adenosine and saw the delta waves. Started Procainamide and admitted.

 

[Groove]

I had to read about this in at least 4 different texts before getting my head around it, but here's an attempt at a summary
-Orthodromic WPW can/should be treated like run of the mill tachyarhythmias without excessive worry. It looks different, but not ugly.
-Antidromic WPW-associated AVNRT is what we're all taught to worry about. Fortunately, this rhythm is ugly, and not something you're likely to be inclined to simply rate control.

Because a) It's always a good idea to shock unstable tachyarhythmias b) Procainamide works for stable v tach, antidromic WPW and a fib with RVR c) even the cardiologists perform pretty poorly when trying to use criteria to distinguish aberrant conduction from v tach...

-When in doubt treat as v tach.

Another pearl I learned was that your antidromic WPW patient is going to be the 28 year old who is talking to you about the fluttering in his chest, but the v tach is going to be the 50 yo who is diaphoretic and clutching his chest.

Hope that helps.

👍 Nice, Wilco.

 

[fiznat]

-Orthodromic WPW can/should be treated like run of the mill tachyarhythmias without excessive worry. It looks different, but not ugly.
-Antidromic WPW-associated AVNRT is what we're all taught to worry about. Fortunately, this rhythm is ugly, and not something you're likely to be inclined to simply rate control.

Man, the pre-excitation in your orthodromic example is barely perceptible. I'm not sure I would have even noticed it if it weren't posted as such, and even then...

When I was working on the ambulance, our standard protocol was that calcium channel blockers were contraindicated in wide complex rhythms-- which seemed like a decent catch-all for paramedics. We were supposed to use Amio or Procanimide as an alternative.

Sneaky WPW is scary stuff...

 

[Zanegray]

I had to read about this in at least 4 different texts before getting my head around it, but here's an attempt at a summary
-Orthodromic WPW can/should be treated like run of the mill tachyarhythmias without excessive worry. It looks different, but not ugly.
-Antidromic WPW-associated AVNRT is what we're all taught to worry about. Fortunately, this rhythm is ugly, and not something you're likely to be inclined to simply rate control.

Because a) It's always a good idea to shock unstable tachyarhythmias b) Procainamide works for stable v tach, antidromic WPW and a fib with RVR c) even the cardiologists perform pretty poorly when trying to use criteria to distinguish aberrant conduction from v tach...

-When in doubt treat as v tach.

Another pearl I learned was that your antidromic WPW patient is going to be the 28 year old who is talking to you about the fluttering in his chest, but the v tach is going to be the 50 yo who is diaphoretic and clutching his chest.

Hope that helps.

And... its something like orthodromic = 98% antidromic 2%
so for the most part you could treat WPW like other narrow complex tachyarrythmias and get away with it. Just be alert for that wide complex is what I learned.

 

[kat82]

Steve Smith summarizes this issue best in his blog:

"4) Atrial fib with WPW is very recognizable: there are bizarre QRS with multiple morphologies, and very fast rhythms with short R-R intervals. If you can find any R-R interval shorter than 240 ms, then AV nodal blockers are definitely dangerous."

http://hqmeded-ecg.blogspot.com/2011/05/wide-complex-tachycardias-2-cases-what.html