Diastolic pressure in V-Tach with pulses.

[Handsome Robb]

So had a call today during my internship.

VT with pulses, pt was A&O, walking, talking, joking around, not really complaining of anything other than mild SOB and a "knot" in his throat.


Not really relevant though. My question is why is it that the diastolic pressure stays high while the systolic drops causing a very narrow pulse pressure.

The last pressure I saw before they sedated and cardioverted him in the ED was 121/106. Original pressure on scene was 178/90.

My undereducated and sleep deprived guess is that vascular tone is still intact therefore keeping a relatively constant diastolic pressure? Whereas the cardiac output is compromised due to the fast ventricular rhythm, inadequate ventricular filling along with the loss of atrial kick. The drop in CO causes the changes in systolic blood pressure, correct?

Sorry if this doesn't make any sense, I'm beat from today.

 

[Aprz]

I wonder if it's similar to heart failure: decreased filling for the reasons you mentioned therefor decreased output, and eventually backing up.

 

[Arovetli]

Yes. The inherent pressure in the system is represented by the DBP with the SBP giving you the pressure the heart is able to create. The vasculature is in good shape and compensating keeping the DBP up but you have a serious and rapidly worsening problem with the heart.

Any PP less than 25% of SBP is cause for concern and any PP less than 25mmHg is indicative of critically low stroke volume.

From onscene to ED your PP has decreased from 88mmHg to 15mmHg. Quite significant. Also note the MAP value. It has only decreased from ~119 to ~110 so the body has compensated thus far to maintain CPP. This is why your patient is still able to joke around.

 

[Brandon O]

All the explanations above make sense to me. I will say, though, that I have often found that trying to divine physiological whys and wherefores from diastolic vs. systolic comparisons is not always prima facie obvious by working from general principles, and you can end up with equally plausible explanations for totally opposite relationships. There's a lot of bouncing between external forces and internal equilibration and it's not always clear what comes out on top.

 

[Arovetli]

Just wondering, was an antiarrythmic trialed either in the field or in the ED prior to cardioversion? From what you described I wouldn't but I know alot of medics would be headed straight for amiodarone-ville.

 

[Handsome Robb]

Just wondering, was an antiarrythmic trialed either in the field or in the ED prior to cardioversion? From what you described I wouldn't but I know alot of medics would be headed straight for amiodarone-ville.

I was pretty quick to hang an amiodarone drip. We also popped the pads on him just for peace of mind, did a 12-lead to confirm although it was pretty obvious from the 4-lead h34r: and drove the the ER. He had a pretty decent history. AMI x 5 although no stents, CVA x3, HTN, hyperlipidemia, A-Fib, VT and was prescribed amiodarone along with diltiazem, lisinopril and a statin. We found out he had conveniently run out of the amiodarone the day before.

We were pretty close to the ER, about 7 minutes driving routine, which we did. My preceptor and I had been talking about the decline in SBP and how we were getting closer to the point of possibly needing to sedate him and cardioverting if we had been farther away. The physician at the ER said they would have tried amio before jumping to cardioversion even if we hadn't started it in the field. They waited for our total dose to go in before deciding to use the electricity.

Just wondering your reasoning behing why you say you wouldn't have hung an antiarrythmic? It's always been my understanding that even if the are "stable" in VT that you want to fix it quickly because they can deteriorate pretty rapidly when they hit that point.

Thanks for the explanations, that's what I thought but I wasn't sure. As far as the MAP goes I understand that, it just amazed me how calm he was and mostly without any complaint. Should have done a better job of explaining that.

Edit: Note to self and all other new medic interns, don't ask to see a different lead when they are in V-tach, it gives your preceptor ammo to poke at you with later :lol: It amazed me how much it looked like a rhythm coming from a rhythm generator. Almost "too perfect" if that makes sense.

 

[Arovetli]

Just wondering your reasoning behing why you say you wouldn't have hung an antiarrythmic? It's always been my understanding that even if the are "stable" in VT that you want to fix it quickly because they can deteriorate pretty rapidly when they hit that point.

Thanks for the explanations, that's what I thought but I wasn't sure. As far as the MAP goes I understand that, it just amazed me how calm he was and mostly without any complaint. Should have done a better job of explaining that.

Edit: Note to self and all other new medic interns, don't ask to see a different lead when they are in V-tach, it gives your preceptor ammo to poke at you with later

Sorry I should have been more clear in the other post. For one EMS here only has the option of bolus dose amio. Two, the literature isn't exactly favorable
on it.

http://www.ncbi.nlm.nih.gov/pubmed/18156531
http://www.ncbi.nlm.nih.gov/pubmed/20370763
http://www.ncbi.nlm.nih.gov/pubmed/16492484

I wasn't meaning to suggest your care was inappropriate sorry if it sounded that way. I think you did a good job.

Isn't it interesting how the truly sick patients usually aren't complaining whereas the one's BS'ing are complaining about their 1,000,000 on a 1-10 scale pain.

And you should want to see more than lead 2 in a wide complex tach.

 

[Handsome Robb]

Sorry I should have been more clear in the other post. For one EMS here only has the option of bolus dose amio. Two, the literature isn't exactly favorable
on it.

http://www.ncbi.nlm.nih.gov/pubmed/18156531
http://www.ncbi.nlm.nih.gov/pubmed/20370763
http://www.ncbi.nlm.nih.gov/pubmed/16492484

I wasn't meaning to suggest your care was inappropriate sorry if it sounded that way. I think you did a good job.

Isn't it interesting how the truly sick patients usually aren't complaining whereas the one's BS'ing are complaining about their 1,000,000 on a 1-10 scale pain.

And you should want to see more than lead 2 in a wide complex tach.

Sweet thank you, I'll take a peek when I get home, I'm at work right now.

That's why I did the 12-lead right away. My preceptor was more joking with me because I asked him to change it on the monitor before the intermediate had finished placing the 12-lead.

I'll admit that I still don't fully understand what I'm looking for on a 12-lead when it comes to VT other than confirming that it truly is VT rather than a fast supraventricular rhythm with WPW or something of the sort and even at that I feel like I still am incorrect in what I just described. I've been working on 12-leads and slowly improving but there's so much to learn!

I've gotten some fantastic help from some users on here as well, they know who they are.