Pacing PEA/Asystole

[TrueNorthMedic]

So I had an interesting pt the other day.

We were transferring a 68 y/o male from a small regional hospital to a large university hospital for cardiology. He had been having near syncopal episodes over the last day and went in to the hospital to get "checked out". Lo and behold he is in a 3rd degree block at about 38 bpm. So we get called to take him to the big hospital.

On the transfer he is quite stable and comfortable with minimal complaints, just feeling "a little off", cx and alert with a blood pressure of 108/76. Still at a rate of 38 but nicely perfused. I have dopamine ready as per cardiologist orders and pacing pads on....just in case.

Then, as I'm watching the moniter and having a nice conversation with the pt, he converts to a normal sinus rythym at about 90bpm for about 10-15 seconds. And then........nothing but p-waves on the moniter for about 6 seconds. (This felt like an eternity.) During the p-waves the Spo2 waveform goes flat, and the pt goes very pale and moans "Oh, it's happening again". Then, suddenly he's back in his 3rd degree block at 38 bpm. His color returns and he states he is feeling normal again. He said during the episode that he felt everything going "grey". This happens 3 times during the hour and 20 min transfer. The longest episode was 7 seconds.
So clearly, this gentleman is in need of a pacemaker.

But I was thinking during the transfer, what if he does not convert back into his 3rd degree block and he just continues on staying in his PEA with only p waves on the moniter? Technically he is now a pulseless arrest and I should just start CPR, and maybe give some Epi, by the book.
But I would have tried pacing him first. I think it would have worked, since I watched him go from a perfusing ryrhym to a PEA. Thankfully we made it through the trip just fine and his rythym converted back each time.

Would it be wrong to pace PEA in this case?
I don't think so, but what does everyone else think?

 

[VFlutter]

He was going into what is called Ventricular Standstill which is the truest form of a complete heart block. Sometimes they will regain a spontaneous rhythm with stimulation like a Sternal Rub but other times it progresses into a prolonged cardiac arrest. This patient should have had the transcutanous pacemaker on demand mode with the rate set 5-10 bpm below what he was asymptomatic at and absolutely be paced if in Standstill or PEA. This is an AV conduction issue and easily fixed with ventricular pacing. Dopamine really isn't that great, Epinephrine is better, and Isuprel is best.

 

[E tank]

Would it be wrong to pace PEA in this case?
I don't think so, but what does everyone else think?

Non conducting p waves is not "PEA". You wouldn't expect a pulse with just p waves and if you could see his heart, the atria would be contracting.

If his permanent pacemaker (that he has by now) would pace him in that rhythm, why wouldn't you?

 

[TrueNorthMedic]

This patient should have had the transcutanous pacemaker on demand mode with the rate set 5-10 bpm below what he was asymptomatic at and absolutely be paced if in Standstill or PEA.

So I should set my pacer to 30-35 bpm, and when he went goes into a ventricular standstill, the pacer will start for a few seconds, and then stop when he converts back to the 3rd degree block at 38bpm? I was thinking start the pacer only if his ventricular standstill became prolonged, say 10-15 seconds or more. I felt that his episodes were short enough that pacing for such a short time would not be a good idea. But what your saying makes sense; avoid the ventricular standstill altogether.
Also, I did wonder when the cardiologist wanted Dopamine instead of Epi. I don't have access to Isuprel.

Non conducting p waves is not "PEA". You wouldn't expect a pulse with just p waves and if you could see his heart, the atria would be contracting.

I got my terminology wrong. I know there would be no pulse with just p-waves and only the atria contracting, so since there is electrical activity and he was pulseless for those few seconds, I considered it to be a PEA. Non conducting p waves is the correct term (or ventricular standstill).

 

[CALEMT]

Would it be wrong to pace PEA in this case?

I can hear my cardiology teacher in my head right now. Technically PEA (due to there being no corresponding pulse with the electrical activity) but also technically not PEA. It's ventricular standstill, like VFlutter the truest form of a complete heart block. In this case pacing is the best route. The electrical system is there, it just needs help conducting throughout the heart. Maybe the cardiologist want dop for the alpha and beta response? Again, like VFlutter, epi would be best for the pre-hospital *ground* setting.

 

[E tank]

Dopamine, IMHO, should be abandoned. Isuprel would be a great choice if it weren't so expensive and therefore forbidden for use by the bean counters. When they ask me if I know how much Isuprel costs I ask them if they know how much a full arrest costs.

 

[VFlutter]

So I should set my pacer to 30-35 bpm, and when he went goes into a ventricular standstill, the pacer will start for a few seconds, and then stop when he converts back to the 3rd degree block at 38bpm? I was thinking start the pacer only if his ventricular standstill became prolonged, say 10-15 seconds or more. I felt that his episodes were short enough that pacing for such a short time would not be a good idea. But what your saying makes sense; avoid the ventricular standstill altogether.
Also, I did wonder when the cardiologist wanted Dopamine instead of Epi. I don't have access to Isuprel.

That is how I personally would handle the situation, others may approach it differently. Not saying what you did was wrong necessarily. The pacer would pace them if they drop below 30 and stop if their intrinsic rate increased back above 30.

We commonly had these patients in the unit while they await their pacemaker. The episodes of standstill are very upsetting to the patient (And staff), can cause them to vomit or seize, and occasionally they will arrest. The few uncomfortable TQ paced beats every now and then is usually the better option than waiting for them to code or vomit and aspirate.

https://emj.bmj.com/content/19/1/86

 

[Tigger]

My medical director "requires" us to pace 3rd degree blocks regardless of symptoms because of the risk (which by his own admission is not backed by evidence) of the patient developing ventricular standstill. I am not sure why we cannot use demand pacing for this, we aren't supposed to use demand pacing for anything.

It hasn't happened to me yet, but you can imagine the last patient in a 3rd degree who was basically asymptomatic was none to pleased with the crew for being "subjected" to pacing on the way in.

 

[Peak]

My medical director "requires" us to pace 3rd degree blocks regardless of symptoms because of the risk (which by his own admission is not backed by evidence) of the patient developing ventricular standstill. I am not sure why we cannot use demand pacing for this, we aren't supposed to use demand pacing for anything.

It hasn't happened to me yet, but you can imagine the last patient in a 3rd degree who was basically asymptomatic was none to pleased with the crew for being "subjected" to pacing on the way in.

He wants you to fixed pace someone who has ventricular activity?

 

[Tigger]

He wants you to fixed pace someone who has ventricular activity?

For whatever reason every agency I work for wants fixed pacing no matter what. And yes. Spoken repeatedly in both school and M&Ms, pace every 3rd degree. Be interesting to hear how we got to this point. He is a young, very pro-EMS, former paramedic regional medical director, so it isn't like we're stuck with some dinosaur.

 

[VFlutter]

For whatever reason every agency I work for wants fixed pacing no matter what. And yes. Spoken repeatedly in both school and M&Ms, pace every 3rd degree. Be interesting to hear how we got to this point. He is a young, very pro-EMS, former paramedic regional medical director, so it isn't like we're stuck with some dinosaur.

Pacing can be a somewhat difficult skill if not done frequently. Many people confuse pacing types, sensitivity settings, etc. Also it is easy to misinterpret fusion / pseudofusion as capture or not recognize lack of mechanical capture. Asynchronous pacing, although not ideal, is probably the safest bet. It is not cool to see someone brady down to asystole on demand mode with inappropriate settings. For example, we had a patient go into Ventricular Standstill on a Demand pacer because the sensitivity was set as such that the P waves inhibited the pacer. Always check your capture threshold and sensitivity if you are going to use demand.

 

[E tank]

Asynchronous pacing, although not ideal, is probably the safest bet.

Chance for R on T just a managed risk?

 

[VFlutter]

Chance for R on T just a managed risk?

Assuming you are setting the pacer rate appropriately above the intrinsic rate I wouldn't think that R on T causing VF from a Transcutanous pacer is very likely. Even in perfect conditions, a transvenous or epicardial in VOO, it is not all that common. And relatively speaking it's easily treatable.

But there are plenty of cases of it happening intra/post op and with malfunctioning pacers.

 

[E tank]

Assuming you are setting the pacer rate appropriately above the intrinsic rate I wouldn't think that R on T causing VF from a Transcutanous pacer is very likely. Even in perfect conditions, a transvenous or epicardial in VOO, it is not all that common. And relatively speaking it's easily treatable.

But there are plenty of cases of it happening intra/post op and with malfunctioning pacers.

Assuming that the native rate stays below the set rate, R on T won't happen. But if someone is sitting there watching it, that wouldn't be a problem. FWIW, in my world, as far as malfunctioning TV or TT pacing malfunction, I think those are more of a matter of capture failure (or operator error) more than dangerously timed pacing. I've never seen an R on T event from pacing.