Chapters Transcript Video Irregular Heartbeats and Rhythms Manju Pai, MD, discusses the wiring of the heart and what happens when there is an irregular heartbeat. Welcome to cardiovascular conversations with Minneapolis Heart Institute. Your podcast for the best in cardiovascular content. Cardiovascular Conversations is a new, creative and engaging content source for the latest and greatest in cardiology topics and innovation. We are your hosts, Fred, Um, use and I'm Jason Hicks. Enjoy the podcast. Yeah, wear interviewing electro physiologist Dr Manju Pie from the Minneapolis Heart Institute. The topic of discussion is irregular heartbeats or rhythms and why they're so important. Doctor Pie will be examining the normal physiology of the heart's electrical system. In addition, he'll touch in the various irregular rhythms such as SPT Atrial fibrillation, P A, C S and P. V. C S. So, in the famous words of John Travolta in Greece, let's get this electrifying podcast underway. We don't need the really complex description, but maybe just walk us through the wiring of the heart, right? So in the most general sense, the way I explained, at least to my patients is just like a building or a house. There's electrical wiring that runs from top to bottom, and so you have an electrical impulse that starts the top of the heart 60 70 times per minute and that electricity shoots down and causes the heart to squeeze and to contract. And if there's any kind of faulty nissen that electrical wiring, whether we have some kind of short circuiting or extra electrical wires, it can lead to irregular, abnormal heart rhythms or palpitations. And we could get into the specifics in terms of what those different wires or called. But that's kind of the basics of it. And in general, most of this faulty wiring happens over time. The electrical, whatever just becomes faulty, or do you find that a good amount of the time? This is something that someone's always had. This is something that's genetic. Yeah, good question. I think it's a little bit of boat. So for most common bread and butter garden variety S V. T. S, it's actually probably something that we were born with. We were born with extra electrical wiring, and it's it's kind of a curiosity is toe why someone can manifest symptoms when they're five years old versus 50 versus 90 years old, but it's typically something we're born with. On the other hand, over time, there could be changes to our heart remodeling, um, changes from stretch or pressure over years, and that can lead Thio abnormal, faulty wiring as well. But I think it's a little bit of half and half. But you know, if if you have an otherwise healthy 20 year old female, it's probably some something that she was born with rather than something that developed because of some type of condition. So getting into some of the actual diagnoses here, Andi, thank you for sharing your presentation with us because I think that helps us sort of break this interview down a little bit. So can you discuss S V t with us? What's actually happening there? Are there subsets? What's the most common type on then? Ultimately, how do you How do you deal with it once you have these patients in your in your office? The way that I generally describe an S V t is that it's any type of fast heart rhythm that's coming from the top chamber of the heart or the atria. And there's ah, few different mechanisms that can cause s VTs. But most commonly it's because we have a second or extra electrical wire. So if you take a quote unquote normal heart, you have one electrical wire and electricity is moving from top to bottom. And if we have a second electrical wire, we can get into the situation where the electricity takes, Ah, left turn or a right turn, and it finds a different way to go or a different loop or circuit. And it goes into this fast heart room, and that's the most prevalent or popular mechanism. Sometimes instead of the Sinus node, which just a normal pacemaker of your heart instead of the Sinus node firing, there could be another area that decides to fire another spark. And that could be another reason for an SBT what we call in atrial tachycardia. Eso those air the two most prevalent mechanisms. And if you have ah, younger person, the most prevalent mechanism just by statistics is that they have a second electrical wire. And as you get older, if you have a history of prior ablation zor prior surgeries or you have a history of atrial fibrillation in, uh, you may have a higher chance of having an atrial tachycardia Later in life. I promised myself that I won't get granular, but I don't know if we're going to see you again. So I want to ask this question more for myself and a drama for this Ortho drama. Can you give me a little snap it on that, right? Yeah. When I talked about most of these S V t is happening because there's a second electrical wire. There's two different areas of the heart that can happen in the most common type of SPT is something called a V nodal reenter in tech cardia or a V and R T. There's a second pathway sitting in the A V notes on that small little section in the septum of the heart. There's a second pathway, and it's kind of just spinning around there and causing these fast heart rhythms. And again, I'm being a little general. But if that pathway is anywhere outside the A V node, meaning it's on the lateral wallets outside of the septum, that's what the's anteed romick or or third romick, Um, tech cardio czar anteed romick. Or don't draw Mick just means which way is the tech cardio spinning. So you need a road down from the atrium to the ventricle and you need a road back up from the ventricle to the atrium, so it needs to spin both ways. I mean, think about when you're commuting and you're going from your house toe work. You need one way to get there in one way to get back there, so you need to roads. And so when you say anti drone, make an Ortho draw make it just means which roads are you taking? Ortho drama Tachycardia means that you're going from the atria to the ventricle down the a V node. And what that means for the E k. G is since you're going down the A V node. It's a narrow, complex tachycardia. A V note is your highway so it doesn't take it. Doesn't take a long period of time to get from your atria to your ventricle. So you're curious is narrow, and then you're going back up the pathway. Um, when you go back from the ventricle to the atria, you don't see that portion on the E. K. G. An anti drama tech cardia is when you're taking the pathway down from the Patriots, you're not taking your taking the accessory pathway. And so because you're taking up the pathway, it doesn't have the high velocity properties of the A V note. So it takes longer. And so you see a wide cure s So that's W p w. That's Ah, manifest. You can see it on the e k g manifest pre excitation. And to drum attack Cardia is your typical wide complex tachycardia that's due to W p. W or an accessory path. Okay, so we've we've made our diagnosis. Is SBT one of the most common diagnoses that you take care of our bread and butter is atrial fib relation. I'd say over 50% is atrial fib relation. And the reason for that is a disease of life. The older we are, the higher the chance will have atrial fib relation. And we can't cure it. And, you know, we treated and we manage it as opposed to SBT, which we can cure with an ablation. You did mention, though, that the majority of the time you can take care of the problem in the E. P lab with respect SPT. What percentage is that cure rate? I should. It depends on the type of SPT but generally for a V and r t I. Usually the success rate by the literature is probably more than 95%. I tell patients that the chance of recurrence is probably about 5%. Maybe a little lower meaning. What's the chance that we think? We we got it. But sometimes people need a second ablation, maybe about 5% or a little lower. But generally its success rate is more than 95% moving forward. Then I think, into the bread and butter a fib. When do they need to go see the doc? My opinion is that anyone with atrial fibrillation in should see cardiology at some point to at least discuss their options. There are many people who can be treated with a blood thinner alone and don't need some kind of rhythm therapy, whether it's an anti arrhythmic or ablation. But you don't necessarily know who that is. For example, I see Ah lot of people let me back up and say that with atrial fib relation. The question is, should we manage this with rate control or rhythm control? Meaning we see someone who is in atrial fib relation and, um, their heart rates are in the eighties, meaning they're not too high, and they feel okay we think they feel okay. Is it okay just to put them on a blood thinner and and let them roll? Or should we try to make our efforts to get them back into a regular rhythm? And and that's the question There is data from a couple of decades ago where show there there was no real benefit to either approach, whether it's rate, control, rhythm control. And obviously I'm not talking about people with poorly controlled heart rates and not talking about people who are obviously very symptomatic. But I think I think a fault with some of that data was that are anti arrhythmic, aren't very good and they're very toxic. Success rate for ablation procedures and the risks of them were different than than they are now, so I think it's a different question. But I do think that there's some people who still treat a za rhythm control or a rate control method instead of instead of pursuing a rhythm control method. And I see a lot of people who have a fib who have normal heart rates and are feeling okay, but we decide to cardioverter them to see how they do, and they feel markedly better. And you see this with all types of diseases, with aortic stenosis, whatever, where our bodies have an amazing ability to compensate or we minimize ourselves, and we think we're doing okay. But we don't realize that are functional. Capacity has dropped over the last one year or two years, etcetera. So I I think that for those reasons, it's very reasonable toe have at least initial consultation with cardiology at some point toe to discuss some of this. And what are some of the complications of a fib? Untreated? The two major complications that I talk to patients about are, of course, the risk of stroke, and that's a difficult question. And there's there's, uh, there are a lot of variables behind that. We obviously all know about the Chad Chad's vast risk calculators, where they assign a certain amount of risk compared to whether you have high blood pressure, diabetes, etcetera and so that's Ah, that's, I think, in depth conversation between you and the patient, about the pros and cons of roll into coagulation. There's a lot of factors behind that. Obviously, you know, it's it's kind of slam dunk if you've got a 85 year old female with diabetes and a weak heart. But it's a little harder when you have, ah, 60 year old gentleman, maybe no other risk factors and maybe just high blood pressure, and you've got to talk about it to the other major complication is, um, what we call a tech cardio induced cardiomyopathy. And so people who have atrial fibrillation and maybe they're not really feeling it. They're not aware of it. But behind the scenes, their hearts, they're going at 120 beats per minute, 130 beats per minute. Most of the time, it's not an unusual situation. After a couple months or three months, they start feeling a little more short of breath, start accumulating some fluid, and they come in with an ejection fraction of 30% 40%. Because of this, that is kind of scary, and I don't think we recognize that particular. I think we all recognize stroke risk Azaz the big one. But I don't think we we think often enough about the the whole tachycardia induced or the if have induced cardiomyopathy. If you're able, Thio, get them out of a fib. Is that something that can be reversed or is it permanent? Short answer is yes. It's generally reversible. It's generally reversible. Obviously, there's caveats that, but I think the vast majority of people, if it's truly and a fib induced cardiomyopathy and you get your get the rate under control, so not necessarily out of a fib. But get the rate under control, their ejection fractions will typically normalize. I want to follow up question on that one. Done, too, for like, long term consequences for this. These cardiomyopathy is. How long does it take for remodeling to occur where it's you're like, Okay, where there's really no advantage to getting them out of a fib? Or they've already had remodeling so that their ejection fractions gonna probably gonna be baseline low to begin or their new baseline. I think that it's always the right thing to do to attempt to get them back to a regular rate, no matter the time period, because there is always a very reasonable chance that you can normalize, if not significantly, improve, the ejection fraction. We do wonder how well these patients will do after they go to the lab, and they are pulled out of a fib. How long? What's the eso you mentioned? 95% roughly with SPT. Maybe, maybe a little give or take. What about a fib? Success rates range anywhere from about 50 to 80%. About a quarter to a third of people will will require more than one ablation. If you look at people who have had to, ablation is the success rate can probably go into the mid to high eighties, so it's a little bit better. And a lot of that success rate depends on one the type of atrial fibrillation they have, whether it's paroxysmal or persistent, so people with paroxysmal or less a fib tend to have a better success rate. Their other risk factors. You may have a lower success rate if you have a cardio myopathy. If you have diabetes, if you're older. If you have renal failure, etcetera, there's probably some creates the fact that you might have ah better success rate. If you're a higher volume center, so can you briefly walk us through? What an ablation from start to finish kind of looks like, uh, experience. E want the e p experience. You're in ablation procedures, a procedure that takes about 2 to 3 hours. It's not a surgery. It's a procedure that's done with catheters and I. V s in atrial fibrillation. Procedure is generally done under general anesthesia. It's just more comfortable for the patient. S V. T procedures are usually done under conscious sedation where you're you're you're nicely asleep, but you're breathing on your own. We put Ivy s into the groins, typically about 2 to 4, depending on the procedure and the right and left groins. It's typically not always typically of Venus procedure. So most of the most of the Ivies air in the veins, and we put tools up into the heart, and we cauterized the areas where these abnormal impulses originate from People stay overnight and go home first thing next morning. But there are some centers that discharged the same day. You don't generally have the same post surgical experience, meaning there's no pain, etcetera, SPT. Procedures people feel pretty good later that day. Atrial fibrillation. It's a little more of a complex procedure in terms of more colorization or ablation, and people can feel what I I just say, kind of crummy for a couple days, kind of like you got over a bad cold there got beat up a little bit, but nothing like like surgery. And typically, how are you eliciting these dysfunction to occur so that you can map out the areas where you're able to oblate eso for so for a super ventricular tachycardia? Let's say we're dealing with a pathway. Let's say we're dealing with a V and R T. We have to prove it to ourselves What the mechanism is Is this a V and R T? Is this a natural tachycardia? Which means we have to get the patient to go into the fast heart rhythm to know exactly what we're dealing with. And we have ways to do that. There's different types of pacing maneuvers, meaning if we instill a p A C at the right time, If we use the medication like adrenaline, we can typically induce it. I make it a point to talk to my patients and say the biggest downside of an SBT procedure is if we can't do sometimes we can't take care of it. What's the risk of? That's probably about 5%. It's low. But for me, that's one of the worst parts of my job is someone comes in. They put a lot of emotional resource into this procedure, and I have to tell them we couldn't do much. It's rare, but it can happen. And sometimes people come back in two months later and all the stars align and we take care of it. But it can. It sounds like there are two different kinds of ablation, or two different ways in which you can apply radio frequency and cry. Or are there more than that? And which one do you use? Is there a preferred approach for civilian use, meaning outside of research protocols? Those were the two types. If you look at the data right now, it looks like their non inferior meaning. It's an either or approach. When my patients ask me about it, I I kind of say it's like asking a tennis player to choose their racket. It's really what you feel comfortable with. I wouldn't say that one type radio frequency versus cryotherapy delivers better results right now where we are right now and there's there's other modalities under research and under under study right now, but nothing that's prime time. What do we need to know about complications with this procedure. What should the primary care folks know about it? Let me just get back toe one, you're saying just in terms of how we approach and a fib ablation. I talked about how we approach SPT ablation the A fib. Ablation is just a little different. The major limitation for a fib and the reason we can't cure it, is we still don't have a good understanding of where a fib originates from and where we need to cauterize it. We know that the majority of a fib signals originate from areas around the pulmonary veins in the left atrium of the heart, and that's where we cauterize. The reason paroxysmal, if it does better, is its earlier in the disease process, presumably, and so it's still localized the pulmonary veins. And so we're burning there. We think we get most of it, but as the disease progresses, it tends to remodel left atrium so there's other areas or triggers, which cause atrial fib relation. And that's really where all the money is right now behind a fib. And every year when you go to a conference for the last years upon years, you're trying to find other areas in the left atrium to cauterize. Invariably, they've been met with varying degrees of success. But that's the problem. That's why people need repeat ablation. Is you're looking for other areas that could trigger atrial fibrillation. So at a baseline, you're going after the pulmonary veins. But big question is, where do you go after that? To springboard off that a little bit and I'm not. I won't have you digress too much, but some of these conferences that you've gone to what are some of the newer, uh, latest and greatest technologies that have been out there for looking at different ways to solve the A fib dilemma? It can be broken down into the durability of the equipment. So let's say you deliver an ablation lesion. What's the chance that you actually killed the myocardial rather than just caused the Medina? And it's gonna It's gonna springboard a couple months later when you're done with the procedure. So different types, energy delivery that ensure that you've actually delivered a good lesion to There's different types of mapping software. So when we're doing the procedure, we're putting tools with little electrodes that tell us what the voltages or like and where we think the atrial fibrillation may be coming from. And so the quality of this mapping equipment are we seeing interesting electrical signals in this portion of the heart, which may be indicative of where the atrial fib relation may be coming from. And then, like you were talking about earlier, different types of energy delivery, whether it's cryo or versus radio frequency. And so what are some of the complications that we can expect with ablation procedures, complication rates? I'll break it down again into S V T vs atrial fibrillation just because S V T is a smaller procedure. E think the complication rates overall maybe about 5%. Severe complications, 1%. You can think about any type of growing access. Complication. You're putting tools in, what our worst case scenarios. We have tools in the heart. There's always a risk of perforation. People needing immediate open heart surgery. Uh, the risk, I always tell people is the most common type of SPT Again is a V and R T, which means that pathway is right next to the A V node. So often times we're cauterizing about five millimeters away from the A V nodes. So if you cauterize Davey node, leave it dependent on a pacemaker, that risk is incredibly low. I don't know what the recent data suggest, but my guess it's is that it's much less than 1%. With our current technology and our mapping tools and software, it's it's a very low risk. It's not zero. I think it was probably higher 15 years ago, 20 years ago than it is now. And then for the purposes of time. Because we're trying to be very mindful of your time. We're gonna move on P A, C S and P V C s. Is that OK? Yeah, I think the ventricular e. I think we could talk to you about e could. I know I could I would love to, but we're not going to. So p. A. C s. PVCs something. We see a lot. We have people coming in with palpitation complaints. More often than not, I would say we see PVCs on the rhythm strip and there we all know that they're very common. Is there a point in time, However where? Okay, there are a lot of these and we need to probably do something about it. They are generally asymptomatic generally not always, but generally asymptomatic p A. C s especially many times they're like, you said, an incidental finding. Many times we don't necessarily have to intervene. PVCs, however, can sometimes be problematic. PVCs tend to be more symptomatic than P. A, C S and P V. C s can be harmful. So if people are having a lot of PVCs, they can sometimes lead to an associated cardio myopathy. If you look at the studies, typically the percentage has to be more than 10 to 20%. It would be very unlikely with someone with the PVC percentage of 5% to have unassociated cardio myopathy, and you see it more frequently with someone with a burden greater than 20% as opposed to atrial fibrillation. Cardiomyopathy. Cardiomyopathy is not always reversible, so sometimes you see an improvement, but not a normalization. But on the flip side, what I tell people is, if you're having symptoms or you're having a high burden, we think it's probably leading to a cardiomyopathy. Those are two good reasons to take care of it, but I have some patients who have a burden of 50% meaning they're in a by Germany and they have no symptoms whatsoever. And for some of those, we decided to just watch it. So maybe every year I'll get an echocardiogram, maybe a Holter monitor and watch them. Okay, fair enough. So it doesn't sound like there's really any need for medications or that that whole, that whole thing hasn't changed too much, is it? Is there something else that we should be advising our patients to do about their frequent PVCs before they go see the electro physiologist? Well, I guess the question for me would be is like, When do they need to see the electro physiologist, right? And I'm like, Is it? I guess if it's maybe I'm assuming that they're probably gonna be seeing you if their burdens more than 20% they're going Jesus. Something that's all the time. Yeah, I think it's really based upon the burden. So if the burdens more than 5 10% I think it's very reasonable toe. At least get an opinion about it. You know, if the burdens 1% or 2% I think it's reasonable, not tow, not toe, do anything or just to watch it. Can you talk to us a little bit about ventricular tachycardia? How you approach those in the lab and why one would go to the E. P lab versus just getting some other treatment modality, whether it's anti arrhythmic, ventricular tech, cardio ablation, eyes, a little bit of a different beast, and it could be a little more challenging. Oftentimes it arises because someone has had a prior heart attack and with it unassociated scheme it cardiomyopathy. So they have large areas of scar around healthy muscle. And so what we're trying to do is find Theo areas in the scar that could be setting up this this electrical circuit. It could be challenging. Oftentimes, by the time they get to the lab, you're not able to get them to go into the ventricular tachycardia. Maybe because of anesthesia, whatever reasons, or if we do get him go into the tech cardia. It's not stable, so you can't keep them in the rhythm long enough to try to figure out what's coming from. And so you often empirically cauterize or a blade areas of scar where you think this is coming from? What makes it more challenging is that our tools are on the inside of the heart and a cardio, and many times the circuit involves the middle of the heart or the outside of the heart. We've been evolving to doing procedures, EPA, cardio as well. So we're just like when we do a pair of cardio synthesis and we're sticking a needle into that. Bacardi, um, we use that same type of procedure protocol to put catheters on the outside of the heart. But those have risks. It's it's not low risk, and it's not always successful. So that's part of the reason why it makes it more challenging. It's hard to figure out exactly where it's coming from, and even if we do, we can't always access that territory. And it makes it even more challenging for people who don't have prior heart attacks. So a non ischemic cardiomyopathy, it's often difficult to find those areas of scars. Well, there's right now if you with the literature, there's not good evidence to support ablation versus medications, and there's a lot of factors behind that. To me. Personally, my decision tree is based upon. If I want to keep a person on Ami odor own long term. It's one thing if there 90 years old, but if it's a 60 year old guy, I'm trying not to keep them on Ami odor on for 10, 15, 20 years. So I may be quicker to move towards an ablation rather than the older person. But there's a lot of variables, but this is kind of there's just a quick how do I approach it? So we're gonna summarize Thank you so much for your time today. Sorry, we were a little bit over here, but I wanted you to summarize for the front line. Clinicians Thio, let them know things take home points for pearls that you might have for them prior to some of these patients getting referred to you. Or maybe the referral process. In general, you can't differentiate the type of heart rhythm based on symptoms alone. So if if you're hearing about palpitations and you really think it's ah, heart rhythm issue, you can't necessarily tell if it's an SPT versus atrial fibrillation based upon symptoms alone. And, um, some type of monitor really helps toe capture the arrhythmia, too. It does help to capture the arrhythmia in regards to whether this is atrial fibrillation or not. Again, SP ts in general can be harmless aside from the symptoms that they cause and the distress to the quality of life. But they're generally not gonna hurt people or kill people. But atrial fibrillation can, um, And so it's important if Thio to think about atrial fibrillation. Obviously, you know, if you have a 25 year old female, you're probably not thinking about atrial fibrillation. But in general, it's important to capture the type of arrhythmia. It's very helpful to capture the arrhythmia before sending him to cardiology. But there are caveats like we talked about, and it's always reasonable. If you have a high suspicion, it's it's reasonable. Um, it's always helpful. Tow us one to try toe attempt, some type of monitor as well as obtain an echocardiogram. Those two pieces of information are very helpful for us, good to know and again, generally for S VTs. They're not harmful, and it's really about how much it's affecting the quality of their life. And at the end of the day, no matter the type of heart rhythm there's, there's a there could be hiccups and difficulties, but I think well, more than 90% of people were able to get back to their normal quality of life. Dr. Monju Pie electro Physiologist, Minneapolis Heart Institute Thank you so much for your time today. We really appreciate it. Yeah, thanks for listening to cardiovascular conversations with Minneapolis Heart Institute. If you haven't already done so, be sure to subscribe to the podcast. And for lots of excellent clinical tools, be sure to check out the APP for Minneapolis Heart. For more information, please also visit Minneapolis Heart Institute at Minneapolis heart dot com. That's mpls heart dot com and don't forget to review us a swell. This is Jason Hicks, and I'm Fred Meuse signing off until next time. See you soon. Mm, your mother use or reproduction of cardiovascular conversations is forbidden without the Express written consent of Minneapolis Heart Institute or Align a Health. Cardiovascular conversations should not be used for legal purposes, and it does not take advertising money. The content is informational only and is not to be used as a substitute for medical decision making or as medical advice. Some of the opinions of the hosts and guests are their own and not those of Minneapolis Heart Institute or align a health Created by Related Presenters Manjunath Pai, MD My specialties: Cardiovascular disease Clinical cardiac electrophysiology Internal medicine View full profile
