OB case

[Noyac]

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THere has been a lack of clinical caes lately thanks to the trolls. But here's my OB case for tomorrow.

31 yo G1P0 for c/s. New onset ventricular tachycardia intermittently. Has dizzyness, SOB, near syncope with VT. No other PMH. Now on metoprolol. Any questions?

 

[BISof60]

What is causing her VT (of course)?

Any outpatient/inpatient workup?

Preop BMP? perhaps preop Mg?

 

[OB1🤙]

Any evidence of Brugada on EKG? Family hx of early-age sudden death?

Make sure she's not a crack/cokehead, though someone going in for elective c/s probably isn't going to be. Also assuming no psych hx or psych drugs on board that would prolong the QT. Lytes look OK?

 

[Noyac]

Mg was just a little on the low side. Its been replaced.

Outpt workup: Holter monitor revealing VT
Echo completely normal
lytes normal

No Brugada. No family history. No drugs.

 

[Noyac]

What is causing her VT (of course)?

That is the question. You tell me.

Here's a hint, check out pregnancy induced arrythmias.

 

[OB1🤙]

What is she doing when these episodes occur? Stressing herself in any way? Do they ever occur at rest?

Is this catecholamine-sensitive V-Tach?

Am Heart J. 1992 Apr;123(4 Pt 1):933-41.Links
New-onset ventricular tachycardia during pregnancy.
Brodsky M, Doria R, Allen B, Sato D, Thomas G, Sada M.

Department of Medicine, University of California Irvine Medical Center, Orange 92668.

During evaluation for palpitations, presyncope, or syncope, seven pregnant women had documented ventricular tachycardia. Before pregnancy none had a history of significant cardiac disease or symptomatic arrhythmia. The tachycardia rate ranged from 117 to 250 beats/min and lasted up to 65 seconds. Arrhythmia evaluation in five of the patients suggested catecholamine-sensitive ventricular tachycardia. This diagnosis was supported by either a positive relation to exercise or isoproterenol infusion, suppression of arrhythmia by beta-blockade or sleep, and lack of induction of arrhythmia by programmed electrical stimulation of the heart. The arrhythmias resolved in one patient soon after evaluation and in one other patient after 2 months of controlling therapy. Five other patients continued to receive therapy throughout pregnancy. Delivery was accomplished in all patients without significant maternal or neonatal complications.

http://www.ncbi.nlm.nih.gov/sites/entrez?Db=PubMed&Cmd=ShowDetailView&TermToSearch=1550003&ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVMedline

 

[VentdependenT]

Hey, what the hell happens to the fetus if you shock the mom if she's in unstable VT? Does it go into a funky rythm? Does it get brady? A-systole?

 

[Noyac]

If unstable, you shock at 50-100 j. If mom is unstable then fetus is unstable. But there are plenty of case reports that document no adverse events in the fetus after cardioversion.

Here's some articles:
http://www.ncbi.nlm.nih.gov/sites/e...med.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus

http://www.ncbi.nlm.nih.gov/sites/e...med.Pubmed_ResultsPanel.Pubmed_RVAbstractPlus

 

[Noyac]

What is she doing when these episodes occur? Stressing herself in any way? Do they ever occur at rest?

Is this catecholamine-sensitive V-Tach?

I'm not sure what she was doing at the time of the arrhythmia. But it is assumed to be catecholamine-sensitive.

The pregnancy state may be pro-arrhythmic. The mechanisms are likely related to the hormonal, hemodynamic, and autonomic changes that occur during pregnancy. Levels of estrogen and human chorionic gonadotropin dramatically increase.
Hemodynamic changes include an increase in the circulating volume that doubles the cardiac output. This results in myocardial stretch and an increase in cardiac end diastolic volumes. High plasma catecholamine concentrations and adrenergic receptor sensitivity increases sympathetic tone. All of these changes in pregnant women can create an environment conducive
to arrhythmogenesis.

So now, how are you going to proceed. Remember, this is an elective c/s

 

[Planktonmd]

I'm not sure what she was doing at the time of the arrhythmia. But it is assumed to be catecholamine-sensitive.

The pregnancy state may be pro-arrhythmic. The mechanisms are likely related to the hormonal, hemodynamic, and autonomic changes that occur during pregnancy. Levels of estrogen and human chorionic gonadotropin dramatically increase.
Hemodynamic changes include an increase in the circulating volume that doubles the cardiac output. This results in myocardial stretch and an increase in cardiac end diastolic volumes. High plasma catecholamine concentrations and adrenergic receptor sensitivity increases sympathetic tone. All of these changes in pregnant women can create an environment conducive
to arrhythmogenesis.

So now, how are you going to proceed. Remember, this is an elective c/s

First,
Thanks for going back to a clinical discussion.

Obviously they have ruled out everything bad with the myocardium like pregnancy induced cardiomyopathy and vavulopathy, they also ruled out re-entery type tachtcardia, long QT syndrome and drug induced arrythmia.
So, we are left with pregnanacy induced ventricular tachycardia that is catecholamine dependent and being treated with beta blockers.
The fact they decided to wait to term tells you that the epissodes are well controled and the betablocker is effective at least partially.
Intra-op management for me would be:
Epidural anesthesia just to avoid suuden hemodynamic changes that would require pressors, if I need pressors I would stick with Neo versus Ephedrine.
Put the defib pads on the patient and proceed as usual.

 

[urgewrx]

Being an elective case, I would not assume anything. I would talk to the cardiologist and ask him for recommendations. I would place pt in telemetry bed pre and post op. Continue metoprolol. Avoid ephedrine/epi. Probably avoid zofran and droperidol. Defib in room. Probably do an epidermal for same reasons Plankton mentioned.

 

[Noyac]

Very good.

YEs Plankrton, all other causes were ruled out and then the metoprolol was started. By the way females have a naturally longer QT interval than males just for additional info not related to this case but nonetheless interesting.

Urge, how long would you continue the metoprolol?

I did not talk to the cardiologist since he is notoriously poor at giving information and always says that there is nothing to be concerned about. He is the one that said to proceed with the kyphoplasty in a 90 yo female with SOB CP and increasing troponins a few weeks back. So my faith in him is nil. Still not a good way to go about it but I did have the holter results and the echo. Plus I had the pt present in front of me the day before the c/s so I was confident in my assessment.

 

[SleepIsGood]

Being an elective case, I would not assume anything. I would talk to the cardiologist and ask him for recommendations. I would place pt in telemetry bed pre and post op. Continue metoprolol. Avoid ephedrine/epi. Probably avoid zofran and droperidol. Defib in room. Probably do an epidermal for same reasons Plankton mentioned.

Why no zofran? Is it pro arrthymiogenic?

 

[Noyac]

Why no zofran? Is it pro arrthymiogenic?

He's refering to the prolonged QT interval. I wouldn't worry that much with zofran in this scenario b/c it is not a QT interval type problem. I tis a catachol issue. But it is worth discussing. And I never give zofran to c/s anyway. Yes I said never. I give neo or ephedrine. Sure there is probably a scenario were I may give it.

 

[Noyac]

There is more teaching here if any of you are interested.

I asked Urge how long he would continue the metoprolol. No answer. How about the rest of you?

Her HR was 105 pre-op. Whats your plan?

You need a pressor of some sort. Whats your choice? Ephedrine, Neo, Other?

 

[VentdependenT]

There is more teaching here if any of you are interested.

I asked Urge how long he would continue the metoprolol. No answer. How about the rest of you?

Her HR was 105 pre-op. Whats your plan?

You need a pressor of some sort. Whats your choice? Ephedrine, Neo, Other?

Direct acting pressor, non beta adrenergic agonist, would be my choice: Neosynephrine. Ephedrine will cause endogenous release of catechol's.

Metoprolol continuation? Hell if I know. I'd ask a cardiologist. In house I'd titrate it to HR of 60's ONCE SHE IS FLUID RESUCITATED. Sounds like CLONIDINE would be a better choice though.

 

[Noyac]

Direct acting pressor, non beta adrenergic agonist, would be my choice: Neosynephrine. Ephedrine will cause endogenous release of catechol's.

Metoprolol continuation? Hell if I know. I'd ask a cardiologist. In house I'd titrate it to HR of 60's ONCE SHE IS FLUID RESUCITATED. Sounds like CLONIDINE would be a better choice though.

Well the metoproplol will be secreted in the breast milk. Does this change your approach?

And HR of 60 is probably unnecessary since she is not a CAD pt. But some rate control is desired.

I held the metoprolol the morning of surgery b/c mom wanted to breast feed. I felt like I could give it IV if needed and would tell her to wait about 6-8 hrs b/4 breast feeding if I gave any intraop. I didn't give any and I used neo to slow her rate some while increasing her BP after the spinal sympathectomy.

Clonidine was shown to accumulate in the breast milk as well but not to cause significant hypotension in the infant.

 

[Planktonmd]

Direct acting pressor, non beta adrenergic agonist, would be my choice: Neosynephrine. Ephedrine will cause endogenous release of catechol's.

Metoprolol continuation? Hell if I know. I'd ask a cardiologist. In house I'd titrate it to HR of 60's ONCE SHE IS FLUID RESUCITATED. Sounds like CLONIDINE would be a better choice though.

You don't want to go crazy with Beta Blockers preop because you might cause severe fetal brdaycardia.
My target pulse rate would be around 80 and using short acting beta blockers
(Esmolol).
Phenylephrine has very little beta activity and in my opinion is your pressor of choice in this case.
Post op I would titrate Beta Blockers down over a period of 1 month and do another Holter later.

 

[VentdependenT]

Well the metoproplol will be secreted in the breast milk. Does this change your approach?

And HR of 60 is probably unnecessary since she is not a CAD pt. But some rate control is desired.

I held the metoprolol the morning of surgery b/c mom wanted to breast feed. I felt like I could give it IV if needed and would tell her to wait about 6-8 hrs b/4 breast feeding if I gave any intraop. I didn't give any and I used neo to slow her rate some while increasing her BP after the spinal sympathectomy.

Clonidine was shown to accumulate in the breast milk as well but not to cause significant hypotension in the infant.

I was thinking immediately post op.

Preop I could titrate in esmolol (a drip don't sound to bad. Flip it off and yer done in 10 minutes) or metoprolol. I totally forgot the breast milk stuff.

Fetal bradycardia is a bad idea. Thanks plank.

 

[Noyac]

We always need to remember that in OB we are treating more than one pt.