# Cardizem Vs. Adenosine in SVT



## Rialaigh (Feb 26, 2013)

To preface I did to a forum search and then a google search and was not satisfied with the answers I found there.

As the title states. 

What I was told by an EM Dr. is that he would always prefer to give Cardizem SIVP for SVT over Adenosine as long as the patients BP is stable, and by stable he was saying anything over 90 systolic for most patients. He says Adenosine in his experience causes more problems and is just flat out more uncomfortable for the patient and he has had good experience with Cardizem. 

There must be more to this...if Cardizem could be used for most SVT in stable patients with much much more comfort than why is Adenosine so prevalent within the EMS and Emergency Room communities. 



This stemmed from 
a patient that came into the ER. 

Female in her 60's, HR 220-230 SVT, BP 110/70ish (don't remember exactly). Pain a 4/10 more "discomfort". Pack a day smoker but satting 95%+ on room air. History of SVT X 3 times, last one was several months ago, PT has never seen a cardiologist

 Doc said grab an IV and away we went with Cardizem right after we got her vitals and a line. He didn't even flinch or think about Adenosine. 5 minutes after the first dose of Cardizem she converted to normal sinus rhythm, we kept her for an hour in the ED and let her go home. No problems, everything else stayed completely stable. She said the last time she was in the ED she was given Adenosine and it took 3 pushes to get her to convert and hurt like hell (I know it hurts like hell) 


Anyways, whats the dealio people ?


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## 46Young (Feb 26, 2013)

Did the MD have the benefit of labs before going with Cardizem?

Also, in pre-hospital EMS, the educational levels vary greatly. Perhaps the reduced contractility that comes with Cardizem was deemed too great of a risk. If you negatively affect contractility, you may need to push CaCl, and all of this is being done with no labs. Or, you may drop their BP, then have the need to cardiovert them, which is most definitely more painful then the Cx discomfort experienced with Adenosine.

It's not always the best to play games without the benefit of blood work. It's like an aggressive medic wanting to push Bicarb on the pt in DKA or the hypermetabolic, altered drug abuser.

Edit: using a 16G in the AC definitely helps with our success rate when using Adenosine.


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## Smash (Feb 26, 2013)

Calcium channel blockers (we use verapamil) and adenosine are equally effective in reverting AVNRT.  Calcium channel blockers have a greater side effect profile (primarily hypotension).  Adenosine is generally "safer" but it does make the patient feel appalling.  If the patient has had adenosine before and it took 3 doses then it seems absolutely humane to give her something a bit kinder and equally effective given that her BP should tolerate any drops.  The other option would be a little dose of benzo before hand, but I'd probably go with calcium channel blocker as well.


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## VFlutter (Feb 27, 2013)

Anectodal experience: I have only seen Adenosine used a handful of times in the hospital, almost exclusively in the ER or cath lab. We almost always use cardizem for any tachyarrythmia from A fib to SVT. Most patients convert fairly quickly with a bolus and drip. Some patients can get pretty hypotensive with it. Besides that I do not see much reason to pick adenosine.


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## systemet (Feb 27, 2013)

The conversion rate for SVT with adenosine is pretty high, but there are some concerns about its use in pt.s with a hx of asthma or COPD, or on certain meds, e.g. carbmazepine.

Fortunately the duration of action is  pretty short, limiting the severity of most of the effects- although there are case reports of some pretty horrible status asthmaticus.

Personally I like the drug.


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## ExpatMedic0 (Feb 27, 2013)

46Young said:


> Edit: using a 16G in the AC definitely helps with our success rate when using Adenosine.



I have done it successfully on the first dose of 6 in a hand vein with a 22G. What do I win?


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## medicsb (Feb 27, 2013)

I've never had 6 of adenosine not work.  I suppose a potential benefit of CCB (or even a beta blocker) would prevention of recurrence of AVNRT, but that's be short lived if not followed by an infusion or PO dosing.  Before adenosine become common practice, verapamil or levophed were used.


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## Christopher (Feb 27, 2013)

Rialaigh said:


> To preface I did to a forum search and then a google search and was not satisfied with the answers I found there.
> 
> As the title states.
> 
> ...



Adenosine is prevalent because the more common regular narrow complex tachyarrhythmias are reentrant rhythms. Adenosine has a pretty narrow side effect profile for the termination of suspected reentrant NCT.

Cardizem has a huge side effect profile when compared to adenosine, especially for simply reentrant rhythms.

I'm not sure where your MD got that experience that diltiazem was somehow less likely to cause an adverse effect, but perhaps they're one of the few that gives dilt really slow. I do sympathize with the notion that adenosine is extremely unnerving for patients.



Rialaigh said:


> This stemmed from a patient that came into the ER. Female in her 60's, HR 220-230 SVT, BP 110/70ish (don't remember exactly). Pain a 4/10 more "discomfort". Pack a day smoker but satting 95%+ on room air. History of SVT X 3 times, last one was several months ago, PT has never seen a cardiologist.
> 
> Doc said grab an IV and away we went with Cardizem right after we got her vitals and a line. He didn't even flinch or think about Adenosine. 5 minutes after the first dose of Cardizem she converted to normal sinus rhythm, we kept her for an hour in the ED and let her go home. No problems, everything else stayed completely stable. She said the last time she was in the ED she was given Adenosine and it took 3 pushes to get her to convert and hurt like hell (I know it hurts like hell)
> 
> Anyways, whats the dealio people ?



SVT at 220-230 is getting pretty quick for my liking to give a CCB to. Perhaps they should just start with 18mg or 24mg of adenosine for her and be done with it.

Long and short of it is if you suspect a reentrant rhythm, adenosine is the better choice. If you suspect an automatic rhythm, a CCB or B-blocker is the better choice.


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## Veneficus (Feb 27, 2013)

Oh yea?

My doctor can beat up your doctor...



Christopher said:


> I'm not sure where your MD got that experience that diltiazem was somehow less likely to cause an adverse effect, but perhaps they're one of the few that gives dilt really slow. I do sympathize with the notion that adenosine is extremely unnerving for patients.



I wish I had $1 for every doctor that experience a n=1 bad outcome and stopped using said intervention thinkiing that was normal or even likely.

Having said that though, sometimes the side effect or perception of the treatment of a given med is beneficial over the statistical "X drug is indicated for Y condition" for various patients.

Some of it is personal preference. (doctors get to do that)

An example of the former is caugh caused by ACE inhibitors. Sure it may control the BP really well, but the undesired effect is greater than the unappreciated BP reduction for some patients. "suffer with it, it is good for you" is not the proper response. 

In the later, here are a few of my personal choices:

I like promethazine over diphenhydramine and second generation H blockers. Mostly because of the sedation effect. Is it the best drug for a given condtion? I guess it depends on what you consider the best. (people getting it for nausea why anxiously waiting in the hospital don't seem to mind the sedative effect either and then I don't have to give them a banzo on top of it.)

I like dual ab therapy over single. (amox w/clav with azith in particular.) I probably should get some stock in those companies. (don't worry, I can't afford stock, so it won't present an ethical issue)

I love bupivicaine over lidocaine. In my mind it is not even a choice. It lasts longer, usually well after the pt goes home, has a better biochem and pharm profile, makes people happy. That makes me happy. 

I also really like silk suture. It is just more pleasant to work with than the synthetics.

Are these things "better?" I think it is just a different way. I don't get very many complaints. 



Christopher said:


> SVT at 220-230 is getting pretty quick for my liking to give a CCB to. Perhaps they should just start with 18mg or 24mg of adenosine for her and be done with it.



It is a comfort zone thing. When there are lots of staff and tools, you can push the limits a little more. 

Perfect example is permissive hypotension. It actually makes me laugh when I see 90 or 100 systolic as a goal. 



Christopher said:


> Long and short of it is if you suspect a reentrant rhythm, adenosine is the better choice. If you suspect an automatic rhythm, a CCB or B-blocker is the better choice.



Better is subjective.


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## Christopher (Feb 27, 2013)

Veneficus said:


> Oh yea?
> 
> My doctor can beat up your doctor...



Probably. The only MD I see is a pulmonologist (PA referral)...who I recently saw in our trauma room botch 3 A-lines before asking for help, so perhaps I should find a new pulmonologist.



Veneficus said:


> I wish I had $1 for every doctor that experience a n=1 bad outcome and stopped using said intervention thinking that was normal or even likely.
> 
> Having said that though, sometimes the side effect or perception of the treatment of a given med is beneficial over the statistical "X drug is indicated for Y condition" for various patients.
> 
> Some of it is personal preference. (doctors get to do that)



EMS in my area is no different, it seems to be most prevalent with narcotics and benzo's. We've got a pretty wide latitude in Rx choices for many complaints (I have 3 antiarrhythmics for WCT and 3 for NCT), so we too get to benefit/suffer from personal preference; so yeah, providers tend to stick within their comfort zone.



Veneficus said:


> In the later, here are a few of my personal choices:
> 
> ...<snip>...
> 
> Are these things "better?" I think it is just a different way. I don't get very many complaints.



I think all of these are reasonable choices between treatments. Sometimes you have reasonable choices between treatments, other times it is a little more cut and dry.



Veneficus said:


> It is a comfort zone thing. When there are lots of staff and tools, you can push the limits a little more.



Re: CCB's to patients taching above 220...I view this as _The House Always Wins_ sort of thing. At some point you're going to lose the bet that you won't hit the side effect profile (or won't hit it that hard).



Veneficus said:


> Better is subjective.



I think in the case of CCB's for NCT, the phrase "better" has some objective criteria around it.


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## Sublime (Feb 27, 2013)

Chase said:


> Anectodal experience: I have only seen Adenosine used a handful of times in the hospital, almost exclusively in the ER or cath lab. We almost always use cardizem for any tachyarrythmia from A fib to SVT. Most patients convert fairly quickly with a bolus and drip. Some patients can get pretty hypotensive with it. Besides that I do not see much reason to pick adenosine.



On another note the ED I worked in we grabbed adenosine every time and it never failed. Some docs preferred to skip the 6mg dose and jump straight to 12 every time. 

Besides the pain from having to push it really hard and the bad feeling the patient gets from that short conduction pause.. I have never seen any ill side effects and don't see a reason to not use it over cardizem.


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## Rialaigh (Feb 27, 2013)

have any of you had issues with heart pauses that...don't restart..with adeonsine. I know its standard procedure to have the crash cart right next to the patient when pushing adenosine. I am not sure how prevalent it is for the patient to require a shock after pushing adenosine. I would think this would be considered a fairly detrimental side effect if it happens even infrequently.


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## Sublime (Feb 27, 2013)

Rialaigh said:


> have any of you had issues with heart pauses that...don't restart..with adeonsine. I know its standard procedure to have the crash cart right next to the patient when pushing adenosine. I am not sure how prevalent it is for the patient to require a shock after pushing adenosine. I would think this would be considered a fairly detrimental side effect if it happens even infrequently.



Never heard of it ''not restarting''.  Adenosine has an extremely short half life,  so it's not uncommon for the opposite to happen and it not have an affect at all.  That's why it's recommended to be pushed through the AC or higher.  

Also,  if the patient remained asystolic after an adenosine push,  a shock is not going to help.  You don't shock asystole


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## medicsb (Feb 27, 2013)

Rialaigh said:


> have any of you had issues with heart pauses that...don't restart..with adeonsine. I know its standard procedure to have the crash cart right next to the patient when pushing adenosine. I am not sure how prevalent it is for the patient to require a shock after pushing adenosine. I would think this would be considered a fairly detrimental side effect if it happens even infrequently.



Is the crash cart their because of the adenosine or is it there because the patient is experiencing an arrhythmia?

I believe there are a number of case reports about prolonged asystole from adenosine necessitating CPR, but I doubt it is anywhere near a common occurrence.  It is also not unheard of for patient to go in to v-fib in cases of accessory pathway conduction.  

There have been studies on the prehospital use of adenosine.  After a very cursory review, I didn't see an mention of cardiac arrest s/p adenosine.  Feel free to do a more exhaustive search:  www.pubmed.com


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## Veneficus (Feb 27, 2013)

medicsb said:


> I believe there are a number of case reports about prolonged asystole from adenosine necessitating CPR, but I doubt it is anywhere near a common occurrence.  It is also not unheard of for patient to go in to v-fib in cases of accessory pathway conduction.
> 
> There have been studies on the prehospital use of adenosine.  After a very cursory review, I didn't see an mention of cardiac arrest s/p adenosine.  Feel free to do a more exhaustive search:  www.pubmed.com



While this is more than reasonable, I have never even heard of anyone or anyone's cousin's sister's uncle's grandfather who have actually seen this.

Usually if something goes wrong I at least hear about it.


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## Rialaigh (Feb 27, 2013)

So, given the option of adenosine or cardizem in a patient with SVT that is seemingly stable SVT 180-220, BP 110/75, o2% is fine and PT looks okay, what do you go with with on the rig? does transport time factor into your decision? Does your decision change in the ER setting?


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## Veneficus (Feb 27, 2013)

Rialaigh said:


> So, given the option of adenosine or cardizem in a patient with SVT that is seemingly stable SVT 180-220, BP 110/75, o2% is fine and PT looks okay, what do you go with with on the rig? does transport time factor into your decision? Does your decision change in the ER setting?



I think my decision would be based on whether that person was likely to be admitted for more than 12 hours or not.

If I expected a short turnaround, probably adenosine.

If I expected them to be a overnight or longer guest, probably cardizem.


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## Rialaigh (Feb 27, 2013)

Veneficus said:


> I think my decision would be based on whether that person was likely to be admitted for more than 12 hours or not.
> 
> If I expected a short turnaround, probably adenosine.
> 
> If I expected them to be a overnight or longer guest, probably cardizem.



So basically overall health of the patient with a focus on cardiac and pulmonary condition?


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## 46Young (Feb 27, 2013)

schulz said:


> I have done it successfully on the first dose of 6 in a hand vein with a 22G. What do I win?



Did you chase it with a pressure bag or something? That's pretty impressive! 

You win a cookie

J/K


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## Veneficus (Feb 28, 2013)

Rialaigh said:


> So basically overall health of the patient with a focus on cardiac and pulmonary condition?



Basically that or age.


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## ExpatMedic0 (Feb 28, 2013)

46Young said:


> Did you chase it with a pressure bag or something? That's pretty impressive!
> 
> You win a cookie
> 
> J/K



I arrived second on scene. EMT's where already there, one was an Intermediate who had started this 22G on the hand and the lady was a hard stick. I had one of the EMT's hold a pre-filled saline syringe while I slammed the Adenosine as hard and fast as I could then grabbed the saline and slammed it with all my might, immediately lifting the patients arm in the air afterward and hoped gravity would lend a hand also.
It took a couple seconds longer than usual (it seemed like) but it worked. I captured a beautiful before, during, and after rythem strip. I was showing it off all day.


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## Christopher (Feb 28, 2013)

Rialaigh said:


> have any of you had issues with heart pauses that...don't restart..with adeonsine. I know its standard procedure to have the crash cart right next to the patient when pushing adenosine. I am not sure how prevalent it is for the patient to require a shock after pushing adenosine. I would think this would be considered a fairly detrimental side effect if it happens even infrequently.



If by "don't restart" you mean asystole, then yes, there are numerous case reports of prolonged asystolic pauses after adenosine administration. Most of these happen to be when given through a central line and they forget to halve the dose. I've not seen pauses greater than 2-3 seconds in the field or ED with adenosine.

Longest pause I've seen was actually post-cardioversion of symptomatic atrial flutter in the ID with ~8 second pause. The cardiologist was unimpressed while our heart rates doubled to compensate for our patient's asystole.

If by "don't restart" you mean ventricular fibrillation, then yes, there are also cases of adenosine's proarrhythmic nature causing VF. Although, often these have an aspect of polypharmacy or inappropriate administration (e.g. Afib+WPW receiving adenosine).

Verapamil has a ton of case reports of both bradyarrhythmias, hypotensive events, and ventricular proarrhythmias. Diltiazem has less, but they're still present.

Our ED brings the crash cart on any patient receiving a bolus antiarrhythmic, conscious sedation, or cardioversion. Proper preparation prevents piss poor performance.


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## Christopher (Feb 28, 2013)

Rialaigh said:


> So, given the option of adenosine or cardizem in a patient with SVT that is seemingly stable SVT 180-220, BP 110/75, o2% is fine and PT looks okay, what do you go with with on the rig?



My decision is partially patient presentation and partially rhythm interpretation. Our area is unforgiving to paramedics who defer Rx when they're more than capable and equipped to do it, unless the situation truly requires you to take it slow.

Basically, stable SVT of suspected reentry will get adenosine from me.

Stable SVT of suspected automatic focus will get cardizem or procainamide, or metoprolol, depending again on my rhythm interpretation and DDx. As I use a more traditional definition of SVT, SVT with automatic focus includes AF, AT/Aflut, EAT w/ block, and JT.

I'm more likely to let a patient "ride" with EAT (we have a kid in our first due with EAT, multiple ablations w/o help) or a more controlled AF/AFlut.



Rialaigh said:


> does transport time factor into your decision?



Not really, unless I'm close to the hospital and feel the patient needs more "eyes" or we need more capability; I'll probably treat in the field. Usually where I find them.



Rialaigh said:


> Does your decision change in the ER setting?



I've never worked more than extra-hands shifts in the ED, so I would imagine my options would be dictated by the ED MD or a cardiology consult. However, I only see cards in the house when its pacemaker related or going to be a electrical cardioversion.


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## FLdoc2011 (Feb 28, 2013)

Just had a recent case here.... guy previously in NSR went into an irregular wide complex tachycardia.   Hemodynamically stable, felt a little "funny" and uncomfortable but otherwise stable.  HR sustained at least 160-180's with couple bursts up to low 200's.    

We knew his detailed history which guided our therapy but would have happened in a prehospital setting with this gentlemen with an irreg wide complex tachyarrhythmia?


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## Christopher (Feb 28, 2013)

FLdoc2011 said:


> Just had a recent case here.... guy previously in NSR went into an irregular wide complex tachycardia.   Hemodynamically stable, felt a little "funny" and uncomfortable but otherwise stable.  HR sustained at least 160-180's with couple bursts up to low 200's.
> 
> We knew his detailed history which guided our therapy but would have happened in a prehospital setting with this gentlemen with an irreg wide complex tachyarrhythmia?



Procainamide is purpose built for that exact situation (and elective cardioversion). Depending on the shortest R-R I've been comfortable with cardizem in AF w/ RVR and wide complexes, but I generally steer pretty clear without a convincing history of AF w/ RVR episodes.


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## FLdoc2011 (Feb 28, 2013)

Thought process change any if the patient has a known bypass tract/WPW?


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## Christopher (Feb 28, 2013)

FLdoc2011 said:


> Thought process change any if the patient has a known bypass tract/WPW?



Procainamide is your "safe" choice, but in known bypass tract I'm inclined to cardiovert.


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