Hi, this is Eric Prostowski and welcome to another segment of EP on AP. What a delight it is for me to have a friend for many years and an outstanding member of our EP community, Dr. Andrea Russo, who is currently the professor of medicine at the Cooper Medical School of Rowan University and also past president of our society of HRS. Andrea, welcome to the show. Great. Thanks, Eric, for having me here. It's always a pleasure. We've done this before and it's great to have you back. Today, we're going to talk about a topic that you're very familiar with and I think really needs to get out there, which are arrhythmias that occur in pregnancy. So I hope you're okay with that. Sounds great. Okay. Well, let's start with the good old PSVTs. Let's take a situation where somebody maybe had a history or didn't know they had a history of some PSVT, now they're pregnant and you're called in to take care of them. What's your game plan? What kind of drugs do you use? How do you go about that? Yeah. So women, sometimes the first time they're actually presenting with symptoms, they're talking to their OB or they're reporting palpitations and then present with SVT, which can increase during pregnancy, even if it's been preexisting. So one of the things we do, we try some vagal maneuvers early in pregnancy, that's certainly fine. And we treat actually SVT during pregnancy, similar to what we treat in non-pregnant individuals. So you can give some adenosine, very short half-life and safe in that regard, minimal risk of fetal bradycardia, that would be very transient. And then we use for ongoing therapy or even acute therapy, beta blockers, the mainstay of therapy. And typically we'll use metoprolol is one of the more common beta blockers or propranolol. Again, sticking to drugs that we've had the most experience over time with, often very effective for treating acute treatment of SVT, as well as preventing recurrences or minimizing recurrences. So let's say, well, that sounds very reasonable. Let's say it just isn't working in a patient. And they're coming back and this is like their second or third episode, and they've been having to be terminated of the tachycardia each time. What's the next line of therapy you'll consider? Yes, I think is the next line of verapamil can be utilized. And then in some instances, and again, you may not know, is this AV node re-entry? Is it a concealed bypass track? Sometimes for concealed bypass tracks, you may want to use a drug that works directly on the accessory pathway. So you might pick something like flecainide, lots of experience with flecainide during pregnancy. So in terms of drugs, that would be the next step. And when you treat with these, I know in certain circumstances, the OB people don't like you to have certain drugs on board when they're getting close to delivering the baby. Are there any guidelines you want to give us on that? I mean, do you tend to just take them straight through or do you sort of back off on some of the drugs around the period where they're getting ready to deliver? Yeah, that's a good question. It depends on the individual, how much arrhythmia they've been having. Certainly the obstetricians would prefer they not have SVT that can cause hypotension, and that can be more of an issue. But it can cause fetal bradycardia, and particularly during the labor delivery and during that period of time. If they're on high doses, I may back off a little bit if they haven't had any arrhythmias for quite some time. If they're still actively having arrhythmias up until the point of delivery, you may be more hesitant to do so, and you want to monitor very closely for fetal bradycardia. That's great. Well, I've never personally taken a pregnant woman and done an ablation. I know some others have. Do you have any guidance on that? Let's say the drugs just aren't working and you're getting concerned and you want to consider, let's say it's a venal reentry or something like that. What are your guidance points for that? Yeah, so there is experience, and some people do probably use it a little bit earlier than others in terms of ablation for refractory SVT. There's certainly data that zero flora. Now we can do these procedures without the use of fluoroscopy by using different tools, electroanatomic mapping, that you can do this safely in pregnant women. I personally actually have not done it. I've been relatively conservative in that approach, but if I did find someone who really was refractory, and I'm worried about other side effects of more and more medicines, hypotension that could be induced by the arrhythmia, I do think it's a very reasonable thing to do. Again, it's one of those areas too. Pregnant women, there's not a lot of randomized, controlled trials. You're not going to see randomized trials in a lot of these areas that involve pregnancy, but you can do it safely with zero fluoroscopy. That's great. Well, let's move on. Thank you for that. That's a wonderful encapsulation of how to treat that particular rhythm. Let's move on to atrial fib. I don't normally think of atrial fib in pregnancy, although I have seen it just a couple times, but fill us in on what the current data are. It sounds like there may be more common, at least than I remember. Yeah. In fact, that was, I remember too, because I remember giving talks about this years and years ago, earlier during, shortly after finishing training. It was really, I mean, that was a while ago now, but it was- You don't want to go there, right? I won't go there, but it was less common. Now we're seeing more and more arrhythmias, more and more atrial arrhythmias during pregnancy. I think that there's several reasons for that. We certainly have an increased maternal age. In the 40 and older group, we just know overall in the population, the prevalence of atrial fibrillation is increasing. We know that the incidence also increases. It's been increasing as time goes on, increases with age, even in people who don't have a lot of structural heart disease. We also have those with congenital heart disease who are actually living to older ages, so they can actually get pregnant and have children. We start to see a lot of these, more of these arrhythmias, atrial arrhythmias in that group too, but it is much more common than it used to be. We have to kind of think of how we're going to deal with atrial fibrillation and come up with a plan. Drug treatment then, let's say you're trying to, I mean, I guess since you've already discussed drugs, I mean, same kind of drugs that you would use in general to treat AFib if it requires suppression? Yeah, so there are certain drugs I definitely wouldn't use, but there are drugs that we have a lot of experience during pregnancy in general, and I have to, you know, flecainide for a structurally normal heart. Now, I'm not talking about someone who has structural heart disease, but someone who has a structurally normal heart, flecainide is a very safe drug to use during pregnancy. That would be my first line treatment. In addition to some rate control, with all the data coming out with rhythm control, we don't have that data in the population that we're talking about here, pregnant women per se, but, you know, rate control alone, people remain symptomatic, especially if you're pregnant and your resting heart rate's higher to begin with, your rates in AFib are going to be higher. It might be a little more challenging to rate control alone, but I would, you know, probably give them a little bit of a beta block or something like metoprolol or propranolol plus flecainide for rhythm control, and it could do the usual workup, make sure that there's not, you know, thyroid disease, something you're missing, structural heart disease, maybe they have some myopathy that was undiagnosed or something you don't know about yet, but do the usual workup and echo, things like that. So you wouldn't counsel a patient then who's had AFib prior to pregnancy to avoid pregnancy. It sounds like you can manage straight through. Yes, exactly. I would not, definitely would manage throughout pregnancy. If they have known AFib before pregnancy, you can plan ahead, and that's the ideal situation, but I definitely would not, you know, tell them not to get pregnant. I think there's very few things that we warn people not to get pregnant at all, you know, with heart disease now. What if a patient, you know, they get pregnant, they've been on fine, and suddenly you find out they have either myopathy, let's say they're probably not going to have ischemic myopathy, and they have sustained BT. Now you've got to deal with that. Let's talk about, forgetting the drugs for the moment, what are your thoughts on device therapy? You know, I mean, the wearable defibrillator versus even an implantable, what are your thoughts for that group? Yeah, so my overall, you know, recommendation is you treat the patient that you, the way you would treat a patient, you know, to be, to give life-saving therapy, and whether that be, so if they have sustained ventricular tachycardia with it, you know, structurally normal heart, it's easier, you know, obviously they can often respond, if it's an outflow tract tachycardia can often respond to beta blockade or, you know, verapamil or something like that, but, you know, in terms of those with structural heart disease, we start to think of, you know, we want to prevent sudden death, and we certainly, you know, we're worried about the unborn child, right, but we're also concerned about the mother, and we don't want sudden death to occur. So I think there's two different options. One is you could, if they don't already have a device in from pre-existing cardiomyopathy, you can implant a defibrillator during pregnancy, and you can do it safely with minimal, or, you know, some people do it floralist too, but you can't, you can do that. The other option is to use a wearable, you know, defibrillator vest, and have them wear it, you know, all day long, except when they shower, and, you know, maybe not the most comfortable thing to do, but it is something that would keep them safe, and you can implant an ICD, you know, postpartum in that kind of situation. Yeah, I haven't had this come up too much, but in the couple cases I've had, you know, I'm a huge fan of CMR, so you can't do that during pregnancy, right, so I've chosen both times to go with a wearable, only because I knew I wanted to get a good quality CMR before, you know, going forward to just see what I'm dealing with as a substrate, so that's sort of been my approach, but I've only had two or three patients where that's come up. Yeah, fortunately, it's not a real common occurrence, and I think we're starting to see a little bit more patients with pre-existing devices, you know, that we're, again, getting in the age of the 40s, because women can, you know, deliver in their mid-40s, and, you know, have children that are probably even older than that, but so we are seeing people have pre-existing structural heart disease. I'm just going to add, I don't usually do this, but we just published this, and you and I were chatting about it. Anka Shaw from our group just put together a series of 11 patients with IST in pregnancy, just so people know about it. It's not actually well known, and they respond very nicely to metoprolol succinate, and usually it starts around the end of the first trimester into the second trimester, when there's a marked increase in sympathetic tone, and the remarkable thing I found out, even though I had people on 200 milligrams a day, within three, five days of delivery, they could go right back down to, like, nothing or 25 milligrams, so just as an FYI, I know that this is your interview, but I just, since it's not well known that you can get this, this is not so much for the EPs, but for other people who may be watching, especially, hopefully, OBs, that this is something that occurs, and it's often missed. No, that's really important, because people are, you know, people are concerned with sinus tachycardia, sinus tachycardia is common during pregnancy in general, but to the degree of inappropriate sinus tachycardia, and I'm, you know, not aware of, you know, any information out there on that, so that's, that's really important, and that you can treat it and resolve, and even some of these other arrhythmias, I've seen some of these atrial tachycardias, they kind of disappear postpartum, or even some of the outflow tachycardias don't seem to be, you think you're going to ablate them when they deliver, and all of a sudden it's gone, so. Yeah, no, no, I think you're absolutely right, Andrea, and the thing, when I was putting this together with my, my, my fellow, who, Dr. Shaw, started to review the OB literature, and there is this surge of sympathetic tone, sort of towards the end of the first trimester, and as you and I both know, arrhythmias that are prone to be exacerbated with increased sympathetic tone are going to be a problem, right, and then postpartum, it goes that away, and like you just mentioned, the arrhythmia may melt away, so you don't have to worry about it at that point. Right, there's all these physiologic changes that go on during pregnancy, I mean, just the increased blood volume, increased stretch on the atrium, things like increased PVCs, and remember, that was actually a fellow at the time, we did halter monitors on pregnant women, and there are a lot of arrhythmias in there we wouldn't know about, you know, but that we'd get worried about, but they don't go away after they deliver, so it's, yeah, no, I think it's an important, you know, it's an important group to study, we, you know, really have had, you know, fewer arrhythmia studies in, in pregnant women, but I'm glad we're starting to learn more about this. Well, Andrea, wonderful discussion, really, literally top to bottom on arrhythmias in pregnancy, you're always a pleasure to have on this show, thank you so much for adding to our education in this area. Thank you, Eric, thank you for inviting me. Thank you.

arrhythmias

pregnancy

supraventricular tachycardia

atrial fibrillation

treatment options