# Atropine...for PSVT?



## bladerunner (Feb 25, 2012)

I recently heard about someone who stopped a medic from pushing atropine on a person who was in PSVT (luckily). I've been wondering what would have happened if the error had actually been committed...and I can't find it anywhere. Everything I found was for using it when it's supposed to be. 

What do you guys think would happen?


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## Medic Tim (Feb 25, 2012)

atropine works on the SA node. It can increase atrial rate and increase O2 consumption.
these kind of med errors happen. you just need to be calm and really make sure you know what you are giving your pt. I am sure someone else can go into much more detail on this


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## Aprz (Feb 25, 2012)

I believe the parasympathetic nervous system (PNS) has minimal or no effect on the ventricles of the heart. I recall in Dubin's Rapid Interpretation of EKGs, he mentioned this when he was talking about sinus rhythms, junctional rhythms, and ventricular rhythms, and asking the readers "How could we go from sinus rhythms -> ventricular rhythms?" and he talked about how a lot of drugs stimulates the PNS or the vagus (X) nerve being stimulated, but the PNS doesn't affect the ventricles of the heart.

Then I believe Atropine antagonizes acetylcholine (ACh) blocking the receptors for it.

Perhaps he was thinking that over stimulation of the PNS was an issue, but since it's a trachycardic arrhythmia instead of a bradycardic arrhythmia, in my mind, the issue wouldn't be too much PNS stimulation, which I think we'd expect to see a bradycardic arrhythmia (ventricular escape focus), but rather the ventricular cardiocytes are excited from an issue like hypoxia.


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## Medic Tim (Feb 25, 2012)

was it a case of the medic mixing up atropine and amioardone? or he thought atropine would help in some way?


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## Handsome Robb (Feb 25, 2012)

It certainly wouldn't have been good for the guy. Would it have killed him? Probably not but you never know. That's going to depend on his history, age, ability to compensate, comorbidities, the whole nine yards.

To put what Aprz said simpler, you have the sympathetic (SNS) and parasympathetic (PNS) nervous systems. For ease of explanation lets call the SNS the gas pedal and the PNS the brake pedal.  If this doesn't make sense take a couple minutes and read up on their functions but again this is a pretty simple explanation.

Atropine blocks acetylcholine at it's receptor sites (muscarinic sites in the PNS along with a few in the SNS but forget about those for this) you essentially "remove the brake pedal" when it comes to the heart which allows the HR to accelerate. 

So theoretically if this guy had given atropine the patient would have a "motor" (heart) pumping away at a rapid rate with no "brakes" to slow it down. 

Does that make sense at all?


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## 46Young (Feb 25, 2012)

Medic Tim said:


> was it a case of the medic mixing up atropine and amioardone? or he thought atropine would help in some way?



Atropine instead of adenosine perhaps? Probably not, since they're packaged differently, and the dosages are different as well. But then again, so is amio, and you have to run it as a drip, which doesn't exist for atropine or adenosine as far as I know.


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## Medic Tim (Feb 25, 2012)

46Young said:


> Atropine instead of adenosine perhaps? Probably not, since they're packaged differently, and the dosages are different as well. But then again, so is amio, and you have to run it as a drip, which doesn't exist for atropine or adenosine as far as I know.



yeah i intended to put all 3, atropine, adenosine and amioardone. I have heard of some medics coming close to pushing the wrong "A" drug.


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## Feuerwehrmann (Feb 26, 2012)

There was a recent incident near me which involved a medic pushing adenosine instead of atropine during a pediatric arrest..woops..I don't think that it had much of an effect due to adenosine's short half-life, but it's still a mistake that shouldn't be made


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