A. Fib question

[EMperson]

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Hello all,
If you have a hemodynamically stable patient in A.fib with RVR and IV Calcium Channel Blockers do not work, can you also use IV B-bockers as well?
I think I was taught long time ago that this was a no-no, because you can completely shut down the AV node, leading to some type of ventricular dysrhythmia.
But our cardiology fellows always seem to say "give em Metoprolol" after we tell them that 60mg of Cardizem IV has not worked. The one time that I saw it, it worked without a problem.
Am I mistaken in my thinking that two IV nodal agents should not be used?

 

[NateintheED]

There is no absolute contraindication to giving IV B-blockers if your IV CCB's don't work. If you think about it, your IV CCB's are pretty short-acting anyway - remember, you can titrate a dilt drip, so it must be pretty fast on/off. And sometimes you just need a little more push than dilt alone.

Are you at greater risk of overshooting it? Probably. Ventricular arrhythmia isn't necessarily what you're going to get, though. More likely you'll get a temporary high-degree AV block, since you're shutting down the node.

Also, keep magnesium in the back of your mind to use in a-fib. In my experience, it doesn't work that often, but a couple grams over 15 minutes or so can be worth a try.

 

[bartleby]

It depends on the patient. If it is a relatively robust person who simply needs rate control and is normotensive after all that diltiazem, that's
one thing. But your 50kg frail old lady will likely start manifesting some hypotension for you when you start adding a beta blocker in after diltiazem, especially if it's afib plus an active source of infection. Judicious fluids can mitigate this and giving some calcium gluconate can reverse the peripherally-acting effects of the diltiazem, but if the patient's BP isn't tolerating these agents you can consider loading them on digoxin (positive inotrope). It is not going to work quickly, but by this point, your patient is probably going to wind up admitted anyway.

 

[southerndoc]

People always forget digoxin. I've had good success with it when diltiazem doesn't work.

 

[BADMD]

Am I mistaken in my thinking that two IV nodal agents should not be used?

Not necessarily, but you have to do it with care. I've used esmolol after a calcium blocker without a problem. I've also see the patient, fortunately not mine, who developed a high grade AV block then arrested (resuscitated without neuro-impairment) after fairly normal doses.

You may want to use smaller doses or shorter acting agents. I'm not a fan of digoxin in general, but it works.

 

[GeneralVeers]

I've never had Cardizem not work. Sometimes I've had to give up to 40 mg in a refractory patient.

 

[suckstobeme]

Ditto on dig. I've also gone to esmolol without any problems.

 

[DoctorMedic]

but can't you always give glucagon if the b-blocker causes an AV block? not saying always go straight to a B-blocker if CCB don't work but I would think that would make me not as likely to be afraid to use it

 

[Jeff698]

While I've used dig + beta blockers, my current practice is up to 40-60 of dilt. If that doesn't work, I start a dilt drip and admit.

Take care,
Jeff

 

[southerndoc]

While I've used dig + beta blockers, my current practice is up to 40-60 of dilt. If that doesn't work, I start a dilt drip and admit.

Take care,
Jeff

... and if the dilt drip doesn't control it?

 

[BADMD]

but can't you always give glucagon if the b-blocker causes an AV block? not saying always go straight to a B-blocker if CCB don't work but I would think that would make me not as likely to be afraid to use it

If only glucagon actually worked that well. And you need to give huge doses of it. And calcium doesn't actually work that well for too much CCB.

 

[Jeff698]

... and if the dilt drip doesn't control it?

Once I put them on the drip, I've decided to admit them so they go upstairs.

Honestly, though, I don't have many dilt failures.

Take care,
Jeff

 

[southerndoc]

Once I put them on the drip, I've decided to admit them so they go upstairs.

Honestly, though, I don't have many dilt failures.

Take care,
Jeff

What I'm saying is I hope you don't put them on a dilt drip and send them upstairs with their HR still in the 140's.

I've seen some people do that, and starting a dilt drip on someone that isn't responding is a waste of effort.

I primarily use dilt, and if it fails, I use dig. I rarely have anyone that fails this.

To me, putting someone on a dilt drip while their HR is 140 and never responds to that is the same thing as putting someone on a naloxone drip who doesn't respond to a naloxone bolus. Yes, it's acceptable if their HR comes down while on the drip, but if it's not coming down within 20-30 mins, then you have a dilt failure as our cardiologists put it.

 

[EMperson]

So for the guys that use Digoxin, how long does it take to work in your practice? I've heard that it can take up to 8-10 hours? Do you observe them in the ED until they're slower? Is it as effective as CCBs in reducing HR? Let's say that you've already given a ton of Diltiazem, its not working, their BP holds, and then you decide to load them with Digoxin, what do you while the Digoxin is taking its time to work?

Thanks

 

[Arcan57]

So for the guys that use Digoxin, how long does it take to work in your practice? I've heard that it can take up to 8-10 hours? Do you observe them in the ED until they're slower? Is it as effective as CCBs in reducing HR? Let's say that you've already given a ton of Diltiazem, its not working, their BP holds, and then you decide to load them with Digoxin, what do you while the Digoxin is taking its time to work?

Thanks

Most of our cardiologists say just send them to the floor and wait for the dig to take effect. It feels strange letting someone in the 130s go upstairs, but you usually are looking at hours for the dig to work.

 

[Jeff698]

What I'm saying is I hope you don't put them on a dilt drip and send them upstairs with their HR still in the 140's.

Just to be clear, I cover the obvious things long before the drip. What is the inciting event? Are they septic, thyroid storm, etc? Is that what pushed them into a-fib? Have they stopped their rate-control medications?

If they're unstable, I'll cardiovert them. Not much choice there. For that matter, I've been known to cardiovert stable new-onset a-fib (when I'm sure its new) right off the bat. I've also used procainamide, flecanide or amiodarone.

For awhile I'd give them dig when they came in at the same time I'd start with beta blockers. The dig takes a while to kick in. In my experience, the combination would control their rate within about an hour or so. Since I wasn't using only dig, I can't say which was the causative agent, though.

And, if the patient is really stable, I've given lots of IV diltiazem and started them on a drip but their HR is still in the 130s, yes, I'll send them to the floor. I'm single coverage and have other patients who need my attention and that room. We almost always have room upstairs and our hospitalists are good (I trust them), available and have the time to closely work with that patient. More time and attention, in fact, than I can provide.

I've worked in other hospitals where sending the patient upstairs meant no other physician would see them for another 24-48 hours. In those places, no body leaves the ED until they're essentially done. Fortunately, I don't work in those places anymore.

Take care,
Jeff

Oh, BTW, for the OP, I'll mix BB and CCB. I don't do it as a often because I don't have to but, given the right circumstances, I will.

 

[Ryan]

People always forget digoxin. I've had good success with it when diltiazem doesn't work.

Ditto

 

[southerndoc]

Our cardiologists aren't in house and dilt drips require an ICU admission at my hospital.

 

[xaelia]

Once I put them on the drip, I've decided to admit them so they go upstairs.

Default answer to any useless pimping question I didn't know on my inpatient cards month during EM-I:
"I think they need to be admitted."

 

[Apollyon]

Default answer to any useless pimping question I didn't know on my inpatient cards month during EM-I:
"I think they need to be admitted."

That's just like the answer to ANY question regarding O2 sat while in the PICU - it's either normal (>= 96%) or 85%. I was never wrong using that formula. (If they're blue, go with 85% - I am COMPLETELY serious.)

 

[bartleby]

Dig takes a long time to work. But once you're using dig, it typically means that a) you have exhausted your other options, and b) are resigned to waiting hours for it to work. If they are stable, you should leave them be in the meantime. If you start throwing too much CCB or other AV nodal blocking agents while dig loading somebody, you can precipitate complete heart block. Too much much med can be worse than none at all.

If you have a patient who needs rate control NOW, as in they're still in the 180's and are having signs of ischemia or you think they're hypotensive due to the reduced filling times associated with such a rate, they need electrical cardioversion. This risk of this is not "zero" in patients of unclear duration who are not anticoagulated, but sometimes you "just gotta do what you gotta do".

 

[AvocadoLover]

I'd never heard of this precaution of not using beta blockers and ca channel blockers together until recently. Pt w/coarse a fib did not respond to metoprolol x2 and the ED MD was worried about starting a dilt drip. I told him I've never heard of it causing heart block. Later that day I ran into our electrophysiologist and he said it's more theoretical and he would never hesitate to use CCB and BB together.