Atenolol, pregnancy, and SVT

I'm 35 y.o. and am 5 months pregnant. I had a first-ever episode of SVT (reentrant pathway) a few weeks ago. (HR 200bpm for about 3 hours before cardioversion with IV Adenosine.) I was prescribed Atenolol (25mg/day), and also given Metoprolol tablets (25mg) to take if there is another episode. A few questions:

1) I'm very concerned about continuing on the Atenolol, since it's Category D and linked to slowed fetal growth, low birthweight and smaller placentas. I'd like to taper off (under my OB's supervision).  If I go off the Atenolol and have another episode (and take Metoprolol to stop it), is that worse for the fetus than taking Atenolol daily? What is the risk to the fetus of another SVT episode?

2) My blood pressure is normally on the low side (around 101/63 average). Is this at all relevant, either to the importance/harm of taking the beta blocker or to the likelihood of having another SVT episode?

3) If I go off Atenolol, is there any reason that my prenatal care would otherwise be especially complicated by the SVT? (Assuming a cardiologist is available for consultation when necessary.)

4) If I stay on the Atenolol, isn't there a risk to the baby during labor/delivery? Are pregnant women usually told to taper off near their due date? Since I'm planning to breastfeed, I don't want to take Atenolol after the birth.

Sorry this was long. Thanks very much for your help.

[Cleveland Clinic]

mj, thanks for the post.


1) The risk of beta blockers with each preganancy is specific to the condition being treated.  Common sense says the overall
risk of taking a daily medication versus one on an intermittant basis is lower.  Generally in young healthy people, SVT is tolerated hemodynamically, meaning perfusion to organs
such as the uterus should not be markedly impaired. I would discuss this risk with your cardiologist and try to coordinate this question between your OB and

2) Not unless you get significant hypotension from either. That would jeopardize the blood flow to the placenta.

3) Not unless you have recurrent episodes off the beta blocker casuing the above problems.

4) Not specific to the delivery and birth. The risks are as you mentioned above. I think you should discuss this birth plan with your cardiologist and OB with your specific concerns and hopes for your pregnancy. Im sure they will be able to further allay your fears and work to accomodate your wishes.

good luck with everything

[dodgybeats]

Hi,
I just wanted to say good luck with your pregnancy! I am about to have a caesarean section in a few days for my first baby and am pretty nervous about it.  I had my first prolonged episode of SVT a couple of weeks ago - it only lasted a couple of minutes but wow was it scary, I can imagine that 3 hours must have been hell.  I went to the hospital and they did an ecg but of course it was normal by then.  I am worried about having a reaction to the epidural during the c-section (I get LOTS of pvcs and they have gotten worse during my pregnancy) but i don't have a choice.
All the best to you.

[razrifrah]

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