Dr. Bob Underwood (Host): Have you ever felt like your heart was fluttering or pounding against your chest? If your heart has been racing or even skips a beat, and the feeling lasts for more than a few minutes, you could have a condition called atrial fibrillation. Atrial fibrillation numbers are rising in the United States, and this could mean a greater number of people having strokes or heart failure.

Understanding the diagnosis of AFib and how patients carry on with their lives is what we'll learn today from our talk with electrophysiologist Dr. George Grant Heberton on the medical staff at Baylor Scott & White Heart and Vascular Hospital in Dallas.

Dr. George Heberton: Thank you so much for having me.

Host: You bet. Welcome to HeartSpeak, the podcast for Baylor Scott & White Heart and Vascular Hospital in Dallas, Fort Worth, and Waxahachie. I'm your host, Dr. Bob Underwood. Now, Dr. Heberton, welcome to HeartSpeak. You go by Grant, not by George, right?

Dr. George Heberton: Yeah, I go by Grant, that's my nickname, so that's what everybody calls me.

Host: That's awesome. So, can we just start by saying what is atrial fibrillation? I mean, we talked about the symptoms, but what's really going on?

Dr. George Heberton: So, before we talk about AFib, it's probably best to talk about how the heart functions normally. So, the heart, like any motor that we encounter in the world, is actually powered by electricity. And there are a group of cells in the heart that are responsible for setting the tempo or the pace of the heart. the medical term for this is the sinoatrial node, but most commonly we just call it our natural pacemaker. And it fires off about once per second and keeps us in slow, regular tempo.

And people, for various reasons, they can go on to progress to this condition called atrial fibrillation. And what that is, is it's sort of a derangement or an alteration in how the electricity flows across the heart. So instead of a single unified beat once per second, there's chaotic, erratic activity flowing all over the upper chambers of the heart throughout the cardiac cycle. And what that can do is it can make those top chambers instead of beating normally, they can quiver. And it can also make the heart rate go very fast, which can cause not only symptoms, but also more significant medical issues.

Host: So, that quivering activity is actually what we mean when we say the word fibrillation, right?

Dr. George Heberton: Right. It's just a fancy medical term for quivering.

Host: So, what would be the signs and symptoms that a patient might have?

Dr. George Heberton: So there are a number of symptoms that people can have. The most classic one is the symptoms of palpitations or racing heart. But not everybody experiences that. Some people can have more subtle symptoms. They may just feel a little bit tired. Some people tell me that when they exercise, they can't go as long or push themselves as hard. I've had some people that tell me that when they mow their backyard, they notice that they have to stop halfway through and take a break before they start up again. People can have other symptoms like shortness of breath, dizziness, lightheadedness, so it can come in a number of different forms.

Host: Sure. Could it also even be asymptomatic?

Dr. George Heberton: Yeah. So, there are some people that we've made the diagnosis on AFib, and I question them about the symptoms and they really tell me they feel fine. They don't have the fatigue, they don't have the palpitations, and yet we can see clear as day they are having atrial fibrillation. It's probably less common that people are totally asymptomatic. More commonly, it's just sort of kind of subtle symptoms, but we do have some people that truly have none.

Host: Yeah. And that can be determined, once you have an opportunity to really look at the pathway. So, what is a typical route that a patient ends up being referred to you, an electrophysiologist? Would it be from their primary care physician? Would it be from another cardiologist? I'm an emergency physician. Where would they get that referral?

Dr. George Heberton: Yeah. So, there are a lot of ways that it can kind of come to our attention, based most commonly on how the patient is feeling. So, typically, for patients with more severe symptoms, they'll end up seeing either their primary care doctor, or if very bad, they may end up going to the emergency room. And those doctors will obtain an EKG, which may show the atrial fibrillation, and then refer them to us. I do have some patients that have less symptoms where it's just sort of an incidental finding. Some patients show up for a routine physical or they're getting a preoperative evaluation and somebody puts an EKG on them. And unbeknownst to them, they were in AFib and we find it that way.

One other way that we're finding it more and more often now is a lot of these wearable devices like the Fitbit or the Apple watch, people have these and they're wearing them on their routine days. And these devices can pick up that there's something abnormal. And then, the patient either goes to see their primary doctor or sometimes we'll even come straight to a cardiologist, and we'll address the issue starting from there.

Host: Yeah, that's fascinating to think about it in this day and age of technology. Like you said, Fitbit, Apple Watches, there's a number of different things that can monitor that didn't used to be available to the general public, but now is. And, you know, as an emergency physician, I have a number of people that have come in, been put on the monitor and I would ask them if they realized that their heartbeat was irregular and they were in fact in AFib and they didn't even realize it. And they'd never been told that.

Dr. George Heberton: Yeah, absolutely.

Host: So, how would you go about the full diagnosis once the patient comes in to see you? And we talked about the EKG, but what else might be involved?

Dr. George Heberton: So, the EKG is the most important thing to make the diagnosis of atrial fibrillation. We're often usually able to establish it based on that. Now I do have some people that are in and out of AFib. So, when they walk into the office, they may not have it, but they tell me they're having occasional palpitations. And in that case we may get something like we call it a Holter monitor, which is a wearable heart monitor that a patient can wear from anywhere from one to 30 days. And so, that way, if they're having it only on occasion, we can catch the more rare episodes and know that that's what's going on. And then, once we have the diagnosis based either on the formal EKG or the monitor, then there are several other things we can do to kind of do some background checks and make sure that there's nothing else amiss. So, sometimes we'll check labs to make sure the blood counts are okay, the thyroid levels are okay. Some patients will get an echocardiogram to make sure the heart structurally looks all right. So, there are kind of a number of other checks we do, just to make sure there's nothing kind of else of concern going on.

Host: You talked about the irregular beating going on in the top of the heart. Now, sometimes that can be transferred down to the bottom of the heart, into the ventricles, to where it becomes very rapid. And we call that AFib with rapid ventricular response. Can you differentiate between an AFib with a normal ventricular response and a rapid ventricular response?

Dr. George Heberton: When the heart is in AFib, those top chambers are going very, very fast, so they're sometimes going over 300 beats a minute. And if we think about it, a normal rate is 60 to 100. So, the body usually has a system to try to keep the lower chambers, which are the main pumping chambers, from getting too fast, but sometimes even that doesn't work perfectly. So, those lower chambers can start getting 110, 120, 130. And what we do find is that as the rate in the lower chambers gets faster, often patients will get more symptomatic, and it can actually cause other problems. So, it can put stress on other organ systems and stress on the heart itself just from running so fast over an extended period of time. And that's something that we can fairly easily establish is going on based on the EKG or the Holter monitor. And it just lets us know that we have to kind of target additional treatments to get that under better control.

Host: Once AFib is diagnosed, as an electrophysiologist, what might you do to be able to intervene? What is it that you can do to help people who have atrial fibrillation?

Dr. George Heberton: I tell people there are three aims that we look at when we're trying to manage people with AFib. So, the first and most important is preventing serious complications. And one of the most serious possible complications from AFib is forming a blood clot that can cause a stroke. So, what we'll first do is look at the person's risk factors, and we have a sort of scoring system to figure out what is the likelihood that that the AFib could cause a stroke.

And if your likelihood is more than about one in a hundred, we do recommend that we do something to get that risk down. Strokes, while rare, can be very devastating to people, and we want to do everything possible to prevent that. And usually, that is with some sort of a blood thinner to prevent clot formation and prevent clots from breaking off and blocking up arteries in the brain.

Now, moving beyond, just controlling for stroke risk, the other things we want to control, like you said, are making sure the heart rate is not going too fast. Because if we're consistently over 100 to 110, that does put a lot of stress on the heart and other organ systems.

And then, the final thing I want to talk with the patient about is, do we need to try to be more aggressive about getting you back into normal rhythm? And that really depends from patient to patient. So for some patients that truly have no symptoms whatsoever, we don't have to do a lot of aggressive things. Some people are perfectly happy to go through their whole lives and be in AFib, but that's probably the minority of people. Most people do have some symptoms, and they want to feel better. And so for those patients, there are a number of therapies, including medications to get people back in normal rhythm or even a procedure called an ablation.

Host: That's phenomenal that we have these things available now for patients. And so, you hinted at, or actually talked about, some of the risks that are involved, but that kind of alluded to why is it important to get on this early before the patient has been in these symptoms for a while?

Dr. George Heberton: So, one question I think we often get asked is, you know, "I feel fine, so does it matter? Is it okay to just leave it alone?" And the reason we care is that even if you don't have symptoms, the fact that those upper heart chambers are quivering and not beating normally does put you at increased risk for having blood clots and elevated risk for stroke. And in studies, what we see is that the risk of having a stroke with AFib is about five times higher than the risk without AFib. So, it is a pretty large increase for people. We're looking at it the other way, about one in five of all strokes that happen in the United States are attributable to AFib. So, it's definitely something that we don't want to ignore, because anything we can do to prevent people from having this devastating consequence and living longer, healthier lives is something we definitely want to do.

Host: Right. And you could see the blood clot on the wall of the heart with an echo, right? With an echocardiography.

Dr. George Heberton: Yeah. So, fortunately, for people on blood thinner, it's very rare to form those blood clots, but we do see it in people that have not been on medication. Some people will come in and they'll get echocardiograms, and we can actually see areas in the heart where those blood clots are forming. And it's very important when we see that to treat it, because if that blood clot breaks off and goes somewhere, it can cause very serious problems.

Host: Which comes back to why it's so important to treat AFib early.

Dr. George Heberton: Yes.

Host: Yeah, absolutely. So, any closing comments that you'd like share with our audience before we break up today?

Dr. George Heberton: I think probably one of the biggest comments I would make is that, sort of as time has gone on, the treatments have gotten better and better for AFib. Twenty to thirty years ago, if people had fatigue or shortness of breath, we just told them, you know, "I'm sorry, that's just the way it's going to be. You just have to deal with it." And as medications have gotten better and as some of these procedures have gotten better, it's really opened a new avenue for patients to really get back to normal. We always want to sit down and kind of go over the pros and cons of everything with people, but there are measures that we can do to get people back in normal rhythm and keep them in normal rhythm and help them feeling like their regular selves.

Host: Thank you, Dr. Heberton. I think this has been very, very informative.

Dr. George Heberton: Absolutely. Thank you so much for having me.

Host: Yeah, absolutely. Thanks for checking out this episode of HeartSpeak. To find a specialist on the medical staff who treats atrial fibrillation, please call the Heart Rhythm Center in Dallas at 214-820-5306. That's 214-820-5306. And if you found this podcast helpful, please share it on your social channels, and be sure to check out the entire podcast library for topics of interest to you. Thanks, and we'll talk next time.

Baylor Scott & White Heart and Vascular Hospital, Dallas, Fort Worth, and Waxahachie, joint ownership with physicians.