# Third Degree AV Block



## paccookie (Jan 22, 2010)

Your patient is a 48 year old male who presented to his primary care physician this morning with weakness.  He has a history of hypertension, high cholesterol and stents x 6.  He is currently taking Zocor, Lisinopril and Plavix.  No drug allergies.  The physician did a 12 lead which shows a third degree AV block with a ventricular rate of 30 and an atrial rate of 60, QRS complexes are narrow.  The patient's skin is pink, warm and dry, lungs are clear and equal, trachea is midline, no JVD is noted.  Vitals signs are BP 148/62, pulse 30 and regular, respirations 16 and non-labored, O2 saturation 97% on room air.  The physician would like the patient transported to the hospital 20 minutes away, which has a large cardiac center complete with a 24 hr cath lab, EP lab, open heart surgery capability, etc.  Upon your arrival, your patient is sitting in a chair.  What next?


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## NomadicMedic (Jan 22, 2010)

The down and dirty: IV, O2, monitor, sedation with a benzo, TCP and transport... to the closest appropriate facility.


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## paccookie (Jan 22, 2010)

n7lxi said:


> The down and dirty: IV, O2, monitor, sedation with a benzo, TCP and transport... to the closest appropriate facility.



So you would pace even though he is compensating well at this point and is very much alert, meaning he knows exactly what you're doing?  You wouldn't try medications first?  Maybe an epi drip or dopamine?

I'm also wondering if anyone would treat for the potential MI that the pt may be having.


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## Shishkabob (Jan 22, 2010)

O2 NC 2-4lpm
IV saline lock
12-lead of my own, and stay on the monitor, preferably have the pads on.
Transport.



Already well compensated, even with a pulse of 30, so there is no need to do the drugs or TCP unless he starts to go down.  Just monitor and transport, with an IV ready just in case.  



He's obviously had cardiac problems before, so if all he's complaining about is weakness and not stating that this is like previous cardiac episode, I'm not too worried.  If he says this is like he previous episodes, then yes, I'd start getting a bit more cautious with a suspected MI and dealing with the drugs, but the weakness can be a multitude of things, not all cardiac related.




Is the pt compliant with his meds?


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## Melclin (Jan 22, 2010)

Don't really see what the zebra might be here.

Seems a pretty simple management to me. Stability of these types of pts shouldn't necessarily be based on HR/BP as I understand it, but it doesn't matter terribly because its all going to work similarly for us over here. We don't use pacing. 

Aspirin, O2, cannulate, monitor, accurate but expedient history, minimize scene time as much as possible, L/S to the cardiac hospital with notice of arrival for appropriate activation of cardiac services and preparation for pacing.


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## testpilot (Jan 22, 2010)

In my opinion he is stable and basic treatment should carry on until he becomes unstable (decreased LOC secondary to the low rate)

Give him O2, Monitor, IV and txp to the facility.  If you feel uncomfortable then go ahead and apply the pads and be ready for demand TCP.

Good scenario


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## terrible one (Jan 22, 2010)

n7lxi said:


> The down and dirty: IV, O2, monitor, sedation with a benzo, TCP and transport... to the closest appropriate facility.



I'm curious to hear your thought process behind this, why such aggressive tx for a pt that seems to be compensating fairly well (BP, LOC, skin signs, etc.)

O2, IV, Monitor, 12 lead seem to be sufficient to me? could be missing something though?


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## testpilot (Jan 22, 2010)

Also, I wouldn't feel comfortable going with Epi or Dopamine unless there was some refractory hypotension that TCP couldn't fix.  Any other thoughts on this?  
I would treat chest pain as normal and try to get several 12 leads if possible.


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## Melclin (Jan 22, 2010)

paccookie said:


> Maybe an epi drip or dopamine?
> 
> 
> 
> I'm also wondering if anyone would treat for the potential MI that the pt may be having.



Only if he was poorly perfused. Pale, low bp, reduced conscious state. He's none of these things. 

And yeah re the possible AMI, I went with ASA. Nothing more I can do.


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## Tincanfireman (Jan 23, 2010)

testpilot said:


> Also, I wouldn't feel comfortable going with Epi or Dopamine unless there was some refractory hypotension that TCP couldn't fix. Any other thoughts on this?
> I would treat chest pain as normal and try to get several 12 leads if possible.


 
Admittedly, I'm a little out of my -I realm here, but I always understood that 12 leads are best administered while stationary to reduce the amount of artifact. Would it be advisable to stop the unit several times with an unstable patient simply to gather data on heart that is already known to be failing?


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## MrBrown (Jan 23, 2010)

n7lxi said:


> The down and dirty: IV, O2, monitor, sedation with a benzo, TCP and transport... to the closest appropriate facility.



Cookbook medicine strikes again!

Put patient on stretcher, take to hospital.


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## paccookie (Jan 23, 2010)

Linuss said:


> O2 NC 2-4lpm
> IV saline lock
> 12-lead of my own, and stay on the monitor, preferably have the pads on.
> Transport.
> ...



This is what I did with this patient.  O2, INT, monitor, 12 lead, pacing pads standing by.  We did go L&S due to distance.  The ER physician gave atropine when we arrived, which didn't have much of a response.  Pt ended up getting a pacemaker and went home the next day.  

I was wondering how other people would treat this pt as it seems that we are taught that high level heart blocks = pacing.  But no one ever mentions the patients that have high level heart blocks and are compensating well.  I didn't see the need to sedate the poor man just so I could pace him.  I explained all of the options to him and he agreed with my conservative treatment.  I thought about atropine, but I've always heard that atropine isn't effective on high level blocks.  And his BP was great, even a little high, so I didn't see the point of adding catecholamines.  I kept thinking that I might be missing something though.  Thanks for the feedback from everyone!


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## grich242 (Jan 23, 2010)

Just because we can do something dosent mean we should for instance if the pt tolerates his hr which it looks like he does why pace right now? I would start with iv, o2,asa, and monitor, iv because if he does begin to go down the line is already there and may be more difficult later, also if you have ever tried to apply pacing patches to a pt already on the stretcher in the back of a cramped ambulance it can also be tricky, so you may want to apply those prior to leaving. As for the drugs what good are they going to do? in a 3rd degree you have a conduction problem (which is why he got a pacemaker) so how does epi or atropine fix that problem? it dosent thats why pacing is indicated. as for pulling over to do repeat 12 leads again what for? if they are on the monitor you can see the rhythm... what are you going to gain from 2 or 3 more 12 leads? provided the first one is a good one.As for the mi he might be having again bottom line he needs a pacemaker, he is currently compensating well do you want to keep messing with the bp? ie ntg ms etc..for what you think maybe happening? Transporting to the approiate er is key no point if they cant do a pacemaker in that facility.taking a few minutes to prepare before leaving the scene dr office whatever, and discussing the transport and why the iv, and the pacing patches will be better for your pt, we don't have to treat everything we see in most cases our treatments are temporary anyway.


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## Shishkabob (Jan 23, 2010)

paccookie said:


> .  I thought about atropine, but I've always heard that atropine isn't effective on high level blocks.





The reason why Atropine isn't indicated for high degree blocks is because it wouldn't help. As you know, the Vagus nerve innervates the atria and not the ventricles.  With Atropine being a parasympatholytic, it would inhibit the Vagus nerve in the atria, raising the atrial heartrate. But since the vagus isn't in the vents, it has no effect in the His/Purkinje system, so it won't raise the vent rate. 

Atropine won't hurt in a high degree block, but it really does no good to speed the atria up if the ventricles will still be doing their own rate, hence pacing for capture and Dopamine as a last resort.


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## boingo (Jan 23, 2010)

Linuss said:


> The reason why Atropine isn't indicated for high degree blocks is because it wouldn't help. As you know, the Vagus nerve innervates the atria and not the ventricles.  With Atropine being a parasympatholytic, it would inhibit the Vagus nerve in the atria, raising the atrial heartrate. But since the vagus isn't in the vents, it has no effect in the His/Purkinje system, so it won't raise the vent rate.
> 
> Atropine won't hurt in a high degree block, but it really does no good to speed the atria up if the ventricles will still be doing their own rate, hence pacing for capture and Dopamine as a last resort.



The OP describes a narrow complex escape, I would give atropine a try if I felt an increase in HR was needed.


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## Akulahawk (Jan 23, 2010)

paccookie said:


> Your patient is a 48 year old male who presented to his primary care physician this morning with weakness.  He has a history of hypertension, high cholesterol and stents x 6.  He is currently taking Zocor, Lisinopril and Plavix.  No drug allergies.  The physician did a 12 lead which shows a third degree AV block with a ventricular rate of 30 and an atrial rate of 60, QRS complexes are narrow.  The patient's skin is pink, warm and dry, lungs are clear and equal, trachea is midline, no JVD is noted.  Vitals signs are BP 148/62, pulse 30 and regular, respirations 16 and non-labored, O2 saturation 97% on room air.  The physician would like the patient transported to the hospital 20 minutes away, which has a large cardiac center complete with a 24 hr cath lab, EP lab, open heart surgery capability, etc.  Upon your arrival, your patient is sitting in a chair.  What next?


My Tx: VOMIT. However, I _must _qualify that... O2? Yep... but 2 lpm/NC. Good SpO2., no SOB. Monitor: 12-lead of my own, pacer ready to go. IV: at this point, an 18ga, NS TKO (med access), Transport: code 2. 

Now, why? Simple. While this patient has a 3rd Degree AVB, possibly with a junctional escape rhythm, he appears to be basically stable at this point. The pacer and med access is just in case he decompensates. Code 2 transport because he's stable, at this point, not necessary, even being 20 min away, and I can always upgrade if need be. Oh, and conversate with him... if his mental status starts to go, I'll know it pretty darned quickly. I consider this to be pretty simple...


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## 18G (Jan 23, 2010)

Overall, the patient seemed asymptomatic of the low HR. No dyspnea, CP, nausea, etc. I would O2 by N/C, another 12-lead, IV, and transport. The patient is hemodynamically stable with great B/P and SpO2. At this point during the pre-hospital phase, nothing needed treated, just observe closely and be prepared to intervene. But definitely have the pacer pads ready. 

I would not give ASA as the patient is not having any S/S of ACS. Granted, an MI could be causing the block in conduction but with this patients presentation, I would hold off. 

What was his baseline EKG? Did he always have a block that perhaps deteriorated into the 3rd dgree? Doesn't sound like he was on any meds that would have caused a block. 

Did you consider using EtCO2 to monitor during the transport? With a HR of 30 if the patient started to decompensate you would be able to note the reduction in cardiac output through the decrease in EtCO2. 

Sounds like you did the right thing!


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## Melclin (Jan 24, 2010)

18G said:


> I would not give ASA as the patient is not having any S/S of ACS. Granted, an MI could be causing the block in conduction but with this patients presentation, I would hold off.



Why? Are you worried about a AAA? Seems like the block has a fair chance of being associated with a throbus/thromboembolus and ASA is relatively safe.


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## Smash (Jan 24, 2010)

I'd be watching this patient very carefully for either a fall in BP or a rise in BP.

I agree with boingo, atropine would probably be worth trying if rate needed to be increased.

I also agree with MelClin, there is a risk/benefit to be considered with aspirin, and in this case the risk is far outweighed by the potential benefit.


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## 18G (Jan 24, 2010)

My thought for withholding the ASA is the patient is asymptomatic and not displaying anything suggestive of ACS. Yes, the block could be a result of ischemia to a part of the conduction system. 

The block could also be from a natural degenerative etiology, and we don't know if the patient had a block before that has possibly worsened.  

A valid argument can definitely be made to give ASA. It is pretty harmless and can only help. 

The impression jumping out at me from this scenerio does not ring MI or ACS related. The OP said the patient got a pacemaker and went home the next day. So, does not sound like MI related so I would have been right to withhold the ASA.


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## EMTinNEPA (Jan 25, 2010)

The usual... HPI, OPQRST, SAMPLE, initial vitals, all that happy stuff...

Rx = oxygen, IV NSS KVO, apply the pacer pads just in case the patient decompensates, serial 12-leads, repeat vitals every 5 minutes, continuous reassessment, obtain blood samples if the system permits, treat additonal complaints as they arise, and transport.  I'd also probably get out the versed and the atropine and have the unopened meds sitting on the bench seat next to me and at least unzip the compartment that the airway kit is in... no such thing as too prepared.


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## johnrsemt (Jan 25, 2010)

I would do 12 leads,  1 sitting still, the rest enroute(you can do multiple while transporting,  try to do it on smooth parts of the roads, and if you have transported to that hospital, you know where it is smooth); 2 IV's,  Cath Labs need 2 and if the patient crashes, it is great to have 2.  O2, 4 l/m NC, transport non emergent.
   Atropine doesn't help on 3rd deg blocks,  I would have pace pads out, and ready to connect, but not open or on the patient.


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## EMTinNEPA (Jan 25, 2010)

http://www.americanheart.org/presenter.jhtml?identifier=564

The American Heart Association includes atropine in their treatments for third degree AV block.

http://emedicine.medscape.com/article/758454-treatment

According to this document by Drs. Levine and Brown, atropine is likely to be ineffective in _wide complex_ third degree AV blocks.  Paccookie described a narrow complex third degree AV block.


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## Akulahawk (Jan 25, 2010)

With a heart block as described, while atropine would be on my mind, I'd still prefer to go to TCP over atropine. Out here, atropine @ 0.5mg is protocol for all bradycardias, and this would "qualify" under that protocol... the guy is otherwise asymptomatic, so Sacramento County would have the medics wait and watch.

Sacramento County doesn't break down the rhythms. It's a functional result: Bradycardia, narrow complex tach or wide complex tach w/ pulses...


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## EMTinNEPA (Jan 25, 2010)

Akulahawk said:


> With a heart block as described, while atropine would be on my mind, I'd still prefer to go to TCP over atropine.



Same here, which is why the pacer pads would be on but the atropine, while out of the bag, would still be in the box.  I'm still figuring out whether I like electricity or I like chemicals, though.


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## paccookie (Jan 26, 2010)

I actually talked this over with the medical director and he agreed with my course of action.  He said in a case like this that he would have basically done exactly as I did but he would have given 0.5 mg of Atropine, especially with it being a narrow complex rhythm.  

As I said, the receiving ER physician did try Atropine without any success.  This patient did ultimately get a pacemaker and went home the next day.  I only know what the newspapers reported as he was the mayor of one of the three towns in our county.  He conversed just fine during transport.  Only thing that changed was that he began to complain of slight difficulty breathing (difficulty taking a deep breath) upon arrival and that his BP rose a bit during transport, I think it went up to around 160/70ish.  That surprised me because I kept waiting for it to fall.


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## FDWhitey (Jan 31, 2010)

*Great resources*

Thanks for the articles! Our protocols tell us not to give atropine in 2 degree type II or 3rd degree blocks - yet when we get to the ER the MD asks why we didn't give it, but never explains why we should. Now I understand!

Whitey





EMTinNEPA said:


> http://www.americanheart.org/presenter.jhtml?identifier=564
> 
> The American Heart Association includes atropine in their treatments for third degree AV block.
> 
> ...


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