Good morning. My name is Eugene Chung from Mass General, and I'm delighted to co-chair this session on Sports EP, Caring for Athletes with Arrhythmias with Dr. Rachel Lampert from Yale. Just some brief housekeeping items. If you haven't downloaded already the HRS 2025 mobile app, please do so. That'll allow you to not only do surveys, but also to enter Q&A questions, which we'll definitely try to get to during the session. It's a case-based session, and we have four excellent speakers to cover interesting topics in Sports EP. Our first speaker is Dr. Anna Rosenblatt from the University of Texas Southwest, who is discussing what is Sports EP and why do we need it. Good morning. Yes, I'm Anna Roosevelt from UT Southwestern and I'm going to be discussing on what is Sports EP and why do we need it. I have no disclosures. So sudden cardiac death in athletes is rare, but kind of the feared complication of in athletes. An electrophysiologist consultation is appropriate in multiple of the etiologies of sudden cardiac death in this patient population, including hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy and ARVC and some of the inherited arrhythmia syndromes like long QT, brugada and CPVT. Physical and structural causes of death are more predominant in the youth and then ischemic heart disease becomes the most common cause of sudden cardiac death as patients age. So I have three cases to kind of think about through this presentation. One is a 24-year-old female with hypertrophic cardiomyopathy with a beta myosin heavy chain gene mutation and a significant family history of sudden cardiac death in her father and a primary prevention ICD that was placed in her teens who presented with ICD shocks after she had VF while exercising on her Peloton bike, an 18-year-old male with asymptomatic long QT2 who plays in a recreation soccer league and then a 33-year-old male with syncope and an avid runner who was found to have WPW and pre-excited atrial fibrillation. So the RRCP has multiple facets that could take a much longer presentation than 10 minutes but so I'm going to focus on just the identification of cardiac disease. So this involves a pre-participation screening, the evaluation of survivors of sudden cardiac death and then the treatment and management of common cardiac arrhythmias such as atrial fibrillation, SVT but also the management of cardiomyopathies and inherited arrhythmias syndromes. This includes risk factor modification, decision of an ICD as indicated and the risk of continuing to participate in sports as well as the management of patients with ICDs and pacemakers who already have ICDs and pacemakers. In the past year there are two consensus statements that have been published. One by Dr. Lampert here, the HRS Expert Consensus Statement on Arrhythmia in the Athlete, Evaluation Treatment and Return to Play as well as the AHA ACC Scientific Statement of Clinical Considerations for Competitive Sports Participation for Athletes with Cardiovascular Abnormalities. Both of these documents emphasize the transition of paternalistic care and management of patients to share decision making and the risk of continuing to play and how to manage their cardiac disease. The role of the ECG and pre-participation screening has, there's much controversy around this and the addition of the EKG to the 14-point focus history and physical exam increases sensitivity to potentially greater than 90% to identify cardiovascular abnormalities. This increase in sensitivity is due to the fact that there's probably, there's abnormalities in the EKG in over 80% of patients with cardiomyopathies, WPW, channelopathies and this accounts for two-thirds of the death in athletes. As I said, there's limited data for the EKG, there's multiple false positives, inappropriate disqualifications and unnecessary extensive diagnostic workups that can lead to stress in a young athlete. Also there's the ethical dilemma of making, if a patient or athlete doesn't have appropriate access to care to complete the appropriate workup, then maybe the EKG poses more risks. The data that supports ECG screening comes from Veneto, Italy when a pre-participant ECG screening was implemented in the 1980s and over the 20 years there's been a decrease in sudden death that was associated, that was, hypothetically associated with early diagnosis of cardiac disease. It's important that a trained professional is involved in the evaluation of an EKG in an athlete because there can be normal findings and it's important to distinguish the normal findings from the abnormal findings and who warrants further evaluation. Some of these EKG changes come from normal cardiac remodeling in an athlete with increasing isometric exercises and strength training that leads to concentric left ventricular hypertrophy and increasing, or increasing isotonic exercises and endurance exercises that can lead to eccentric LV remodeling and RV dilatation. Some of the normal findings you see in an athlete can be LVH or RVH, incomplete right bundle branch block, early repolarization, Mobitz 1, sinus bradycardia, junctional bradycardia. Abnormalities that warrant further evaluation include left bundle branch block, right bundle branch block with other EKG findings, high grade AV block, ventricular arrhythmias, atrial arrhythmias, as well as brugada type pattern and epsilon wave. Electrophysiology consultations involved in the management of patients who have a sudden cardiac arrest as far as evaluating the etiology of the arrest. Is there a treatment and reversible cause and then is a defibrillator indicated and can they continue competing in sports? I'm not so sure why this keeps flipping. So I'd like to go over just a few diagnoses and how electrophysiology's evaluation of the prior data with exercise and how that affects our management. So for patients with hypertrophic cardiomyopathy, there has been evidence that exercise can increase the VO2 max in a moderate intensity of exercise training program in these patients. And in patients who have a diagnosis of hypertrophic cardiomyopathy, there has been found no difference in death, sudden cardiac arrest, arrhythmogenic syncope and ICD shocks in patients who have non-vigorous exercise compared to vigorous exercise. And so this has led to kind of a change in the guidelines, which may be discussed later in this session, that there's no contraindication for sports for patients with hypertrophic cardiomyopathy as well as those with genotype positive, phenotype negative patients. Sports participation should not change if a patient should receive an ICD or not. It's based on the underlying clinical and genetic risk factors and not on the decision of if they're going to participate in sports. For patients with arrhythmogenic cardiomyopathies in exercise, on the other hand, exercise has found to be associated with increased risk of ventricular arrhythmias, VT and VF, and potentially progression of disease. And the genotype specifically may play a role in the risk stratification and the risk of exercise with sudden death in these patients. And even patients that are genotype positive and phenotype negative, they may also be at increased risk of progression of disease with exercise. So that said, still sports participation should not change the indication for ICDs and is based on clinical risk factors if a defibrillator is indicated. So the return to play guidance from the HRS consensus statement for these patients with arrhythmogenic cardiomyopathy do warn against vigorous endurance sports for athletes with arrhythmogenic cardiomyopathy, especially in those with the high-risk genotypes. For patients with Long QT, we know that Long QT 1 is associated with the lethal events with exercise. With that said, patients who have a diagnosis of Long QT who participate in vigorous exercise, there has not been found to be an increased risk of death, sudden cardiac arrest, ICD shock, or arrhythmogenic syncope. So the treatment of these patients really is based on their diagnosis with beta blockers, ICD when indicated, potentially sympathetic denervation. And with this treatment and avoiding triggers such as medications that can prolong the QT, with treatment, then it's safe for these athletes to return to play. And then lastly, for patients with Wolf-Parkinson-White, there's a low risk of sudden cardiac death. And the management of these patients, if they're asymptomatic, they can continue participating in the sports and their athletic training. And those who are symptomatic should undergo evaluation prior to participation and EP study looking for inducible AVRT, an evaluation of the accessory pathway, and catheter ablation when indicated. So going back to the three cases in our 24-year-old, mid-24-year-old female with hypertrophic cardiomyopathy, she continues to exercise. She monitors her heart rates, and she follows up in device clinic to ensure that her defibrillator is working since there's no strong contraindication for her to continue to participate in sports. And for the patient with long QT2, he was started on Natalol and continues to play soccer. And in our 33-year-old male with syncope and WPW, he underwent an EP study and successful ablation and has returned back to running. So sports to me has multiple facets, but the important part is evaluation of abnormalities in the pre-participation screening so patients can be educated on their risk and treated appropriately to reduce, if there's any risk factor modification that can be pursued. As well as management and evaluation of survivors of cardiac arrest and management of participants with symptomatic and asymptomatic cardiomyopathies with inherited arrhythmia syndromes. And then also, which I didn't cover, management of common arrhythmias in an athlete, including anticoagulation and atrial fibrillation treatment. Thank you. Thank you. Do you want to do one question now or just move on? This is set up to do questions at the end, so we'll move on to the next speaker. So I'd like to welcome our next speaker, Dr. Jim Daubert from Duke University, and he's going to discuss form factor and programming considerations in athletes dealing pacemakers and or ICDs. Well, thank you very much, Eugene, Rachel. It's a pleasure to speak with you today on this interesting topic. Okay. So form factor and programming considerations. So we'll talk about nuances of device programming and device type and things like that in athletes who need a CIED. And much of the focus on athletes and arrhythmias and devices has centered on defibrillators for good reason, but pacemakers are relevant. And there's interesting data on an increased incidence of bradycardia in endurance athletes. So this is data that's been looked at before in this large cross-country ski race in, I think it's in Finland, could be Norway. And in this data, the athletes who had participated in multiple races had an increasing incidence of sinus node dysfunction and need for pacing. And also, if they were faster, if their performance was greater in these races, they had a progressively increasing a dose response relationship with needing a pacemaker. And that applied to men. So it's a bit of a tortoise and a hare situation. So the slower racers, the tortoises eventually caught up with those racers who passed them out on the course since they didn't need pacemakers as much. Interestingly, among women, there was not such a relationship. The bradycardia in athletes has often been attributed to high vagal tone, but there's elegant work showing that downregulation of HCN genes and the current, the funny current that regulates sinus node function is probably more responsible for this. Turning to other indications for pacing. This is a 67-year-old prior elite runner who still is very active running in 5K races, et cetera. This is a case from one of my colleagues at Duke, Al Sun, who shared with me. And you can notice at rest, this patient had a winky-block block on his ECG, but was asymptomatic, had a normal EF negative ischemia evaluation. On treadmill, his conduction improved to from second to first degree, but notice he has a dramatically long first degree AV block with the P wave shown here, QRS, P wave, QRS. So very long first degree AV block. What to do with him? Does he need a pacemaker? Will he benefit? Will we pace his ventricle and worsen his conduction? Al had an elegant solution for this. He implanted a His bundle pacing lead shown here. You can see the lead pointing backwards, posteriorly going into the septum, right atrial lead here, very narrow paced QRS, non-selective His bundle capture. And you can see that his 5K times, which had gone up from 21 to 32, were back down to about 22 minutes. And the patient was very happy. Chronotropic incompetence can be another reason for pacing. I have a patient who is a jogger, avid distance walker with sinus node dysfunction. And chronotropic incompetence, he received an AAI pacemaker and still felt poorly, describing multiple symptoms about especially the onset of exercise. And despite reprogramming his device multiple times, he eventually persuaded his physicians to change his generator to a minute ventilation device. And this also required a number of adjustments, but eventually he's doing very well with his walking and jogging. Of note, he has a first degree AV block, so he may need future upgrades to come, but so far he's doing well. And just to remind you, there are multiple different rate response sensors available. And while a dozen or more have been investigated, there are several that are still available, accelerometers, piezoelectric crystals, minute ventilation, and closed loop stimulation. So in patients who may mainly have sinus node dysfunction, it's important to recognize that exercise-related AV block could occur. And if they're in an AEI to DDD mode and they develop block, while they may not have asystole, they may become very symptomatic with exercise and a sudden drop in rate. These modes are different in different manufacturers and in different scenarios, and some programming is available, different programming, but it's important to attend to those things. To get more complicated, Ben Levine's done some interesting work that the cadence of timing the foot strike with diastole can improve cardiac output stroke volume in patients with CRT devices, something called cardiolocomotor coupling. What about leadless pacing as a solution for athletes so they may not get their pocket device and leads injured with contact? Well, there are some advantages like that and upper extremity movements being problems, but there are disadvantages as well in that the AV synchrony is far from ideal so far and there may be battery longevity problem in a young patient, what to do with the next device and so on, and AV synchrony really falling off at advanced rates. So low burden pacing, it might still be a solution. Turning to defibrillators, ICD programming has been looked at in Dr. Lampert's study and in others. We've seen an important role of inappropriate shocks and programming trials like MATED-RIT have pushed the boundaries of programming to longer detection times, higher detection rates, and seen favorable results. Study in France by Clementi looked at programming VF at 220 with generally favorable results. So these are data that have helped foster programming solutions for athletes who need obviously high heart rates and avoiding shocks at the same time. So this is data on the demographics of athletes in the ICD Athlete Registry and the sports they participated in. The bottom line was that there were no primary endpoints consisting of sudden death or need for external shock in this study. And the finding that programming the detection at high versus very high, higher very high, 240 beats a minute versus below 200 beats a minute did reduce the chance of probability of a shock in these athletes and longer detection times had the same effect as well. Skip over that. So what about the leads? This was looked at as a sub study by Dr. Link in this study. And interestingly, lead survival was similar, 95% at five years in these patients. In general, leads perform more poorly in younger active patients, but at least within the confines of the follow-up in this study. In general, leads did well. Weightlifting, though, fell out as significantly related. If it was significant participation in weightlifting, there was a higher instance of lead failure. Do we need to restrict upper extremities after a device? May be a myth. There's some data that shows no difference when this has not been restricted in patients after device implant. A trial is underway presently. Obviously, there may be differences in athletes doing very extreme movements of their upper extremities, so it probably needs to be individualized. But in general, we may have created more frozen shoulders and problems like that by unnecessarily restricting our patients. And while there's not very much evidence that protecting the device can be done, there are some garments available that have been studied and interestingly reduced anxiety and worry about injury to patients' devices when using these wearable devices. What about swimming? There are issues with swimming in long QT1, and here is a recreational swimmer who has a CRTD device, and we saw this on her recordings. She was in her swimming pool at the time, and swimming pool EMI has been attributed to underwater lights, chlorination systems, underwater pumps, and also pool slide pumps, so an important niche thing to be aware of. There are hazards in golf. These are known as water or bunker sand traps where a player may take relief without penalty, but there are other hazards for device patients involving specific upper extremity movements that trigger lead noise in this patient that was only reproduced by simulating a golf swing. Here's a patient we took care of who presented with syncope while playing college basketball practice. His EKG was remarkably abnormal with deep T-wave inversion. He had apical hypertrophic cardiomyopathy with very thick septum myocardial wall near the apex, and he was thereby indicated for an ICD after much discussion. We settled on a subcutaneous ICD for this patient since he had no pacing indication and no indication for ATP at this point. Well, what might be the role for ATP? Turns out VF is the main arrhythmia in most of the athlete's conditions that we're dealing with. ATP would be more likely to be needed in ARVC, coronary disease, ischemic cardiomyopathy, maybe idiopathic, VT, or congenital, but some of these conditions would have exercise restrictions and sports participation restrictions. So really, ATP is probably less likely to be needed than most other ICD patients, and some data showing that therapies could be reduced in athletes or in HCM patients with SICD as compared to transvenous ICDs. Dr. Lampert's paper recently compared the different types of devices. Transvenous devices, well-studied, but issues with injury to leads and pockets, lead survival, young patients, and all of those issues, whereas subcutaneous or extravascular ICDs may have advantages in not being in the way for upper extremity movements and lead survival probably better and removal of leads obviously much easier. So to sum up, so if pacing is necessary and important to recognize that bradycardia in and of itself, only if it's symptomatic, may need pacing, and there may be other novel solutions like ablation being considered of the autonomic system to prevent pacing, but if pacing's necessary, we wanna try and make it physiologic if necessary, tailor it and optimize rate response, consider the potential for leadless, but there are limitations there. Consider severe first degree AV block as a problem and how to address that, perhaps with conduction system pacing, and that exertional AV block might be intermittent. For ICD programming, high rates, long detection times, VT maybe at 200, VF at 220 are rates to consider. There's more likelihood for shocks and need to think about ablation in these patients. VF really is the main target that we need to think about for ICDs, so rapid rates make sense. Arm restrictions, we've probably been too restrictive in the past, but case by case, sport by sport, things make sense. Device pocket protection might be feasible. European guidelines advise that more strongly, and it may lessen anxiety in patients. Important to remember to attend to the disease-specific recommendations when we're taking care of our patients and consider the need for lead damage. So thank you very much for your attention. Thank you, Jim. Our next speaker is Dr. Molly Shaw from the Children's Hospital of Philadelphia, who will be speaking to us about management of asymptomatic or intermittent ventricular pre-excitation. Thank you, Rachel. All right, so at the outset of this talk, I just want to make this distinction of Wolff-Parkinson white pattern and syndrome. I know people tend to use it interchangeably, but at least for this purpose of my presentation, WPW pattern refers to manifest pre-excitation on the ECG in the absence of any arrhythmic symptoms, whereas the syndrome actually refers to pre-excitation involving arrhythmias due to an accessory pathway. So what is the incidence of sudden death in Wolff-Parkinson white syndrome? Well, the most quoted incidence is 0.1% annually, or one event per 1,000 patient years. But there is a higher risk of WPW-related sudden cardiac death in children, and this is shown in a meta-analysis of 20 studies. So it's really important to know that when you're dealing with a young athlete with WPW, even though the risk is numerically low, it is front-loaded in the first two decades of life. And sudden cardiac death, even in an asymptomatic patient, may be a sentinel event. So for the purpose of this talk, I'm going to begin with a case. This is an 18-year-old male who is an NCAA Division I basketball athlete presented for his pre-participation physical evaluation, and he was completely asymptomatic, no concerning family history, had a normal physical exam, and got a screening ECG, which looked like this. As you can see, the ECG shows a pre-excitation pattern with negative delta waves in V1 and a transition, precordial transition, in V4. And this is most likely a right anterior or a right antereceptor pathway. As part of the workup, our patient gets an echocardiogram. We've ruled out with an echo that there's no congenital heart disease, cardiomyopathy, or cardiac tumors, which sometimes can be associated with a WPW pattern. We also get an exercise stress test, and here there is an abrupt loss of pre-excitation at a rate of 142 beats per minute. So if I was giving this talk in 2012 or even 2015, then according to the consensus statement then an asymptomatic WPW patient with persistent or intermittent pre-excitation with abrupt loss of pre-excitation on an exercise test would really not require any further EP workup and simply needs counseling regarding symptom awareness and perhaps some cardiology follow-up. However, recent data have challenged traditional notions of risk assessment in WPW. The first is that there is actually no association between athletic activity and sudden cardiac death in WPW. Athletic training does not alter the conduction properties of the accessory pathway, and therefore the recommendations, the current recommendations, are the same for athletes and non-athletes. This is an example of a 21-year-old male who was watching TV and had an ambulatory monitor because he had just received the diagnosis of WPW, and as he was watching TV, he had a syncopal episode and then a VF arrest, and you can see his rhythm progressing from SVT to atrial fibrillation to ventricular fibrillation just watching TV. In the largest case control series of WPW patients under 21 years of age, life-threatening events occurred most often at rest or with non-competitive activity. Therefore an athlete with a WPW pattern and no symptoms returned to play during the evaluation period is recommended, so we don't pull them out while we are waiting to complete our evaluation. According to the 2020 ESD guidelines, a distinction is made in that competitive athletes with asymptomatic WPW and EP study is recommended to evaluate the risk of sudden cardiac death. In the largest case control study of WPW patients, again, please note that this is under 21 years of age, and these are all patients with EP data, risk stratification with an EP study was not always accurate. There was a 30% risk, or 30% of the patients with documented life-threatening arrhythmias actually did not meet the high-risk anti-grade accessory pathway conduction criteria with an EP study. So in the same study, a life-threatening event in which a life-threatening event was the sentinel event, 65% of patients, meaning they were asymptomatic up until that point, even with an EP study, we would have missed one-third of these patients. So an EP study is good, but it doesn't rule out a high-risk patient. Now what about asymptomatic patients with intermittent or non-persistent WPW? In another large study of WPW patients, of the 244 patients with non-persistent WPW, 13% of the patients met high-risk criteria at EP study. So if we had followed the previous guidelines, intermittent or non-persistent WPW, no EP study required, we would have missed these patients. And out of these patients, six patients actually with the non-persistent WPW actually had life-threatening events. So current recommendations for athletes under the age of 18 with either persistent or intermittent WPW pattern, an EP study is recommended. For older athletes over the age of 18, particularly those with intermittent WPW, the class of recommendation for an EP study is simply lower because these athletes, there's a survival bias. These athletes have surpassed the highest risk decades of their life, and the data on intermittent WPW is really scarce. But for patients under the age of 18, whether you have persistent or intermittent, we consider that the same, and these patients need to have risk assessment with an EP study. Now, when you take these patients for an EP study, if there is one or more high-risk property during the EP study, catheter ablation is recommended to prevent life-threatening events. However, in athletes without high-risk properties identified on EP study, we think the catheter ablation is still reasonable because, as shown earlier, approximately 30% of patients can fail this invasive screening test. And for athletes with anteroceptal and mid-septal pathways, we strongly recommend the use of cryoablation to reduce the risk of heart block. And patients such as mine with a right-sided pathway, before we go and ablate all these pathways, it is imperative that we rule out that this is not a vesicular ventricular pathway. So now just looking at catheter ablation outcomes of accessory pathways in young patients, there are multiple international registries reporting success rates between 95% and 97% with catheter ablation. The overall recurrence after the first catheter ablation is 5% to 13%, and complications are rare, which include cardiac tamponade, coronary artery injury, and AV block. But of note, there have been no reports of AV block requiring a permanent pacemaker with cryoablation. Given that no procedure is without risk in athletes with WPW, a shared decision-making amongst patients, families, and their EP is recommended regarding catheter ablation, as well as an EP study for risk stratification with discussion of procedural risks, benefits, pathway recurrences, and most importantly, the limitation of our risk stratification tools. So going back to our patient, we first want to make sure that this right-sided pathway is not due to a vesicular ventricular pathway. There are some ECG algorithms that you could use to differentiate whether this is actually a WPW accessory pathway or a vesicular ventricular pathway. But for a more definitive diagnosis, you could actually, without taking the patient to the EP lab, you could administer intravenous adenosine in one of your procedural units and just simply look for AV block. However, if you're in the EP lab, there are specific properties that you want to evaluate to differentiate between a vesicular ventricular pathway and a right antraceptal pathway. So back to our 18-year-old athlete, we did everything I said. He's asymptomatic. He actually has non-persistent WPW. But we know that this doesn't really matter anymore in 2025, whether it's persistent or intermittent. We're going to take him for an EP study. During our EP study, even though the antigrade pathway ERP was shorter on isopraternal, none of the numbers really met high-risk criteria. But before taking the patient to the lab, we had already discussed the shortcoming of electrophysiology studies. And I think one of the reasons these numbers don't pan out is everyone does an EP study in a different way. Some people use general anesthesia. Some people use sedation. Some people use isopraternal. So in this patient, we had that discussion a priori. The patient and the family chose to undergo a preemptive catheter ablation, which was successful with cryoablation. This was a right antraceptal pathway. There were no complications. And the patient has had no recurrence after one year of follow-up. Now I just want to draw your attention to one more manifestation of the WPW pattern. This is more common with right antraceptal and right free wall pathways. These patients are often asymptomatic. Because echo is part of our workup for WPW, you often find this incidentally. Although we've had a patient who was referred for transplantation with an echo that looked like this, and a simple ablation got him off the transplant list. So some of these pathways can cause significant left ventricular dyssynchrony, resulting in dysfunction. And catheter ablation is recommended in these asymptomatic patients to improve ventricular reverse remodeling. So in summary, management of asymptomatic patients with WPW pattern has evolved. And there is a strong recommendation to perform an EP study for risk stratification. The class of recommendation, or the strength of the class of recommendation, depends on the age of the patient, with a stronger recommendation for younger patients. Catheter ablation is recommended for any patient meeting high-risk criteria. But even without high-risk criteria, it is reasonable to perform a catheter ablation after shared decision-making. And in conclusion, non-invasive and invasive tests are imperfect predictors of life-threatening events in WPW. Intermittent WPW has an overall lower but clinically relevant rate of rapid accessory pathway conduction compared to persistent pathways. And given the high success and low complication rate of catheter ablation of WPW, there is a low threshold for catheter ablation to cure WPW and prevent sudden cardiac death in the current era. Thank you. Before we get to our Q&A session, we have one final speaker, Dr. Steve Amann from Mayo Clinic. And he's going to discuss exercise recommendations for athletes with HCM, 2A, or 2B. I have one additional disclosure. I am not an electrophysiologist, and therefore, those intracardiac electrograms are giving me tachypalpitations right now. Do you have WPW? I do not, as far as I know, but I haven't looked. So thank you, Rachel and Eugene. It's my pleasure to talk to you about this fun, nuanced, and important topic. So what do we tell our athletes now with hypertrophic cardiomyopathy? First of all, since I'm a non-electrophysiologist, I will tell you some of the clinical stuff we tell all of our patients to begin with. HCM is common, and it overall has a good prognosis. Most people with HCM live a normal number of years doing normal activities and die from something else. It's not a disease that is fraught with bad outcomes for most patients. We screen their families, we risk stratify them, another great topic for debates. We treat symptoms, and we now encourage our patients to participate in healthy exercise as part of the healthy lifestyle. But we're here today because of these data. We've got Barry Marin's data on the right, and the data that was shown earlier today on the left, looking at a population of athletes who had sudden cardiac death. And hypertrophic cardiomyopathy is as high as 36% in Barry Marin's study, as low as 6%, but maybe 22% clinically if you combine those two slices, which is an overrepresentation of HCM in this population. So from these data, it was deemed that it was high risk for someone with HCM to be a competitive athlete, which led to dogmatic disqualification of patients simply because they had the diagnosis of HCM. And then that had a trickle-down effect, where we told patients with HCM they shouldn't exercise vigorously. And then the notion was HCM patients shouldn't exercise at all. So we have a generation of HCM patients who have HCM and metabolic syndrome, which is actually worse. So fortunately, I think we can move this discussion forward. If we're going to determine how risky it is to be an athlete with HCM, who are we going to compare them to? We can compare athletes with HCM to other athletes, and that's largely what those first two studies did. But that's not the clinical choice a human being makes. They don't get to choose whether they have HCM or not. They're a human being with HCM, and they need to know, is it okay for me to be an athlete or not? And this is where we have to step back from those original data, accept them for what they are, and then look for new ways to examine this. So how risky is it? Well, if there was no risk to being an athlete with HCM, then the prevalence of HCM in the dead population would be the same as the prevalence in the living population, right? I mean, it just makes sense. So the prevalence in the general population is 0.2%, 1 in 500 individuals. If you look at rigorously, systematically screened athlete population, this was in Italy, the prevalence of HCM detected in those rigorous screenings was 0.07%. Makes sense. Many people who have a cardiomyopathy cannot achieve the athletic performance that would be required to be an athlete. So slightly less prevalence there. But again, if you take those two studies, the minimum prevalence was 6%. So there's a minimum 30-fold increase in the rate of HCM amongst the dead athletes compared to living people. So there has to be some association. We don't know that it's causal, but there's some association between being an athlete and having hypertrophic cardiomyopathy and sudden cardiac death being there. But again, as I said, this is really the important question. If you are a physician taking care of a patient with HCM, if you're a family member of a patient with HCM, if you're a patient with HCM, this is the question. What does it mean? Can I play or can I not play? Well, we now have new data. It was shown earlier. First we have the RESET HCM study from Sara Sabari at the University of Michigan that took patients with HCM and entered them in a formal moderate intensity exercise program and showed no signal for arrhythmic events. And guess what? They got in better shape. They improved their VO2 by one and a half, which incidentally, for me, is interesting. It's also the same improvement in VO2 that you see by starting a new drug, Mavacamptin. Then we have a Rachel study that you've talked about. Another disclosure, I'm a co-author, as is my colleague, Dr. Mike Ackerman. This was a study looking at various levels of activity and seeing if there was any signal across increasing intensity of exercise. And in this study, there was no evidence of harm by doing more vigorous exercise. So now we feel comfortable that we can get rid of that dogma that HCM patients should be afraid of exercise, they can improve their general health, and there isn't signal to moderate intensity exercise for these people. But I want to put a few cautionary notes there because the title of today's talk is athletes. So we're talking about competitive training, competition in high-level athletes, and that's different than exercise as part of a healthy lifestyle. So in the LIV-HCM study, it was a non-inferiority study designed to detect non-inferiority, meaning less than 50% increase in rhythmic events. Now, it didn't get anywhere close to that, but that was the study design intentionally thought out. But what if we saw that there was a 10% increase in events? Is that acceptable to us because it meets our non-inferiority definition? It's a rhetorical question. The study would have to be much larger to answer that question. We don't have that answer. The other thing to be cautious about is these are pre-designed definitions of intensity, but vigorous activity is defined as six minutes of exercise one to two times per week. If you were an athlete, if you have an athlete, or if you watch athletes, that's warmup every day. That's zone two cycling that's the race if you're a cyclist. That tells you nothing about the sprints, the weightlifting, the Oklahoma drills, the adrenaline that comes with trying to win a game or make the team or those types of things. That's not included in this vigorous definition. And so there is a subset of those patients who are in the age range we're talking about, teenage to early 20s, that were truly competitive athletes. And there's a chart in the LIV-HCM study that compares them. There's no signal for increased event rates in those. But the point is not to throw out these data and say it's not valid, but just to say these studies weren't designed to really assess our elite level athletes and the high intensity training that they do. Let's pivot and talk about how we fit that into guidelines. So every society now has their guidelines. This is what the American College of Cardiology and American Heart Association use as their rubric for coming up with the recommendations, class of recommendations we use. And if you look at this closely, you can pull out the class one interventions. The benefits far outweigh the risks. Class 2A, the benefits are better than the risks. Class 2B is they're better than or equal to the risks. There's a class three, no harm, which means there's no signal for harm or benefit. But they call it class three and then there's the class three harm at the bottom. I was asked to focus on 2A and 2B, which I think is appropriate. So what is the difference between these two? The real difference between these two is in the class 2A indications, the benefits outweigh the risks. There are data to show it is more beneficial to do this thing than to not do this thing. In class 2B is it may be better, but it might be equivalent. So again, another rhetorical question, are there any data to suggest sports participation is beneficial over non-participation for patients with hypertrophic cardiomyopathy? The answer is we don't really have data that show any cardiovascular health benefit to participation in these sports. What if we think about other class 2A and 2B indications from the HCM guidelines? All of these have data that show that there is a benefit to doing these things in patients with HCM. Actually, these are all class 2B indications in HCM. The challenge comes in the practical application of the guidelines, and this is where I think that we have to be careful so that we are doing the right thing for our patients. We as human beings, not just cardiologists, we are what I call cognitive misers. We like to not to have to think about something. So if we can automate a decision, we wanna automate it. And we have a tendency to take every class one and every class 2A indication and say, do that. There's risk in that, because class 2A doesn't mean every patient should get it. Even class one doesn't mean every patient should get it. There are individual patients who bring their own stuff to the table that might say that's not the right thing to do. But class 2B makes people pause so they don't know what that means. Obviously, class three means stop. So what are the risks if we labeled an indication a 2A or a 2B? Right now in the ACC AHA guidelines, we have competitive sports participation as a class 2B. Many providers who aren't familiar with HCM make this an automatic no, and then the patient family team comes to experts like Dr. Lampert or Mike Ackerman or Matt Martinez and asks for a review of someone who really knows the situation. Is it okay if my daughter or son continues in this sport? If we made it a class 2A and we got into that cognitive miser role and we just automated, yes, you can participate, then who's gonna be there to watch out for the nuances in that patient's clinical presentation of HCM that might say they are at higher risk? It's gonna fall to the third party, which is their job, the team physician, maybe a player's association, those types of things. But it takes out one check gate to make sure that the patient is safe. The way we should be utilizing the guidelines, in my estimation, is like our traffic signals. If you've got a green light, you don't close your eyes and go down the road. You make sure there's no deer or anything down there, but you go. When you get to a school zone, you slow down. You think about things a bit more, you look around a bit more, you look for options. If there's a yield sign, you look closely. To me, class 2B yield is the perfect arena for the shared decision-making discussion of the nuances of risk, lack of proof of risk, but historical data for patients and families that are considering a big investment. And obviously, the wrong way sign, you don't go down that road. So where we stand now is this is a schematic of what the ACC AHA guidelines say regarding around exercise and athletics. Every patient is encouraged to exercise low to moderate intensity exercise as part of a healthy lifestyle. More vigorous activities is reasonable for most patients with HCM. And competitive athletics can be considered as part of a shared decision-making discussion. The overall risk is probably low, but we don't have clear data that the risk is zero. Thank you very much. I have a question for Molly. Molly, I just want your comment on the adenosine test. I use it frequently, and I'm happy when it shows increased pre-excitation, so that then means that I will take the patient to the lab, or when it shows AV block, but with persistent minimal pre-excitation, which means a fascicular ventricular pathway. But when you lose pre-excitation, completely, does this mean you don't have to take the patient to the lab, because we have patients which have adenosine-sensitive pathways, which are not necessarily low-risk pathways? So what's your comment on that? That's a great question. I think the best way to do this is in the EP lab, and these days we're taking everyone to the EP lab. But I think there are some pretty good criteria, just based on the ECG, that this is a fascicular ventricular pathway. I see Reina Tan in the audience. Reina is looking at some of these patients prospectively with ECG algorithms. I think if you see that fascicular ventricular pattern, you already know in your mind, this is fascicular ventricular, and then the adenosine just supports, which you already know. But if you're not sure, you have to take them to the lab. I'm going to ask a question from the social Q&A, and I'm going to direct it to Dr. Daubert. Do you exercise stress test your athletes more than non-athletes, and if so, do you modify the test based on the sport? And then I may add, if they have a device, how does that change things? Okay. So I think, taking the second part first, Eugene, I think there's important indications for utility, let's say, in exercise testing to tweak the rate response, maybe before implantation of a subcutaneous ICD to look at appropriate sensing vectors and suitability of that. So I think those are important factors with exercise. Other questions from the audience? I'll ask Steve a question. Steve, we've talked a lot about that 2A versus 2B, but I think let's kind of think, in thinking about it another way, one of the places where both the AHA document that you led, our HRS document, really agreed was on the importance of shared decision making. So tell us about, you've got a high school kid coming to you, what is that conversation with that kid and his parents? Yeah, it's a great question, Rachel. Yeah, so I give them a less scientific version of what I just talked about there. So I tell them about the historical data that says if you hear about an athlete dying, the data says it's more likely to be HCM than you would think just based on routine prevalence in the population, but that the newer data we have is not able to detect a big increase in risk. And then we re-stratify them for their standard stuff. That re-stratification doesn't necessarily clear them for sports participation. It just tells us about whether or not they need an ICD. We find out what type of other things that they're doing, what are their other, what's their fallback plan if they're not going to be an athlete. So it's a long discussion with them. But then I ultimately also say, look, we have patients in every professional sports league, in every Division I sport category, now with HCM. So it is possible to play with HCM. It just shouldn't be an automatic do not pass and go type thing. Yeah. Thanks. I'm going to ask a question for Dr. Rosenblatt. So at your institution, how do you or EP get involved with a sports cardiology patient? Do they see Dr. Levine first, then he calls you guys? Do you see them jointly? How does it operationally work in your clinic? Yeah. Yeah, Dr. Link has seen a lot of the, most of the HCM patients historically. And usually, they're seen by not just one of our cardiologists who specialize in HCM, as well as Dr. Levine kind of simultaneously. I think those conversations about participation in sports kind of go from there. Do you have other questions from the audience? I have a question. So I'm just going to challenge everyone here a little bit. I'm going to go against the guidelines. I know that there is a class three indication of intentionally not putting in an ICD in an HCM patient just to let them play sports. And I understand that. However, our risk stratification process is not perfect. I worry about my hypertrophs who have a 2.8 centimeter septum. They don't meet my risk stratification criteria. This athlete wants to play sports. And what we heard was there's probably a high risk of HCM in the dead people. So why would I put him on the field without an ICD? I know AEDs and all that are good, but they're not right there. Why would I not implant an ICD in my 28 millimeter septum patient who wants to play sports? I think it's a really good question. So that's one of the reasons why we use both the binary risk factors. Yes or no, do you have massive hypertrophy? But we also use the calculators that include the wall thickness as a continuous variable. And you tell the patient that they have an X percent risk of sudden death in general. And so a 28 millimeter septum in a 19-year-old is a really thick septum. And so we're going to monitor that patient longer. We might repeat the imaging and make sure that 29 isn't 30. So we'll look at that patient more closely. The conversation doesn't just end at that time when it comes back at 20. It's a great clinical scenario. So go ahead, Jim. The binary thing is going to be low in even 3 centimeters with no other risk factors. It's a weird situation there. And I'm sure you're talking about with an MRI and not just echo, so. No, I'm just, I guess my question is whatever risk stratification criteria we use, whether we use the binary version or not, it's imperfect, right? There is no yes or no. And you have an athlete who really wants to play and there is a shared decision making process. I would personally feel much more comfortable putting in an ICD in a patient that I perceive doesn't meet all the criteria but has some baseline risk. So I would suggest for myself, I might put an ICD in that person who was in the chess club. And I think that, because there's kind of two questions. There's the binary nature. Like we all know that risk doesn't go like this. And so I think you look for other things. Is there, maybe was there a cousin that died suddenly and not their father? So I think there's a lot of, I think that binary is not the way to go. And septum is not the only thing. It's just look at an athlete who fits, who's like in that medium risk. But I think the other aspect of it is that individuals with HCM are not at zero risk for dying. And that's true whether they're athletes or they're not. And I would challenge the way we think about the numbers a little bit, because if you looked at young people who die in their sleep, HCM would also be overrepresented because that's what young people are gonna have and die from. And I think it's, and in our LIV study, we found that the rate of arrhythmic events was equal between the athletes or the more vigorous and the non-vigorous. But some of them did occur during running. So if all that you had looked at was, yes, there was an active person who had an event during running, you'd say, ooh, we shouldn't have done that. On the other hand, the non-active people had equal number of events doing other things. So I think it's very important in that conversation to say HCM is not risk-free. And so it's really the question, setting that expectation. And so I think it's really, I approach risk stratification similarly with an athlete and a non-athlete. The other thing I would say is the guidelines aren't law or policy. They're to make sure that we're holding the map with North at the top. And then individual decision-making and clinical judgment comes in. So the point of that class three, don't put it in just law of sports, is you have someone who has 15 millimeters and no risk factors, and let's just throw in a device for this person so it's safe for them to play. That's a different story than that one. So that's where you get to bring your clinical judgment and so, yeah. Yeah, great question, Molly. But the other issue is, where did we get these cutoff points of less than 4% means low risk, 4 to 6% means intermediate risk, and greater than 6% means high risk. So that's specifically what we say, don't fall into that trap in our guidelines. We use that percentage just to inform the patient about the magnitude of their risk. We don't label them based on that percentage. So we say, use the risk factors to screen out the low risk group and then use a calculator to communicate with the family their magnitude. And we don't make a decision based on the pure number. Great point. We've run out of time. Please join me in thanking our panelists and speakers. And thank you for coming. Thank you.

Sports Electrophysiology

arrhythmias

individualized care

sudden cardiac death

pre-participation screenings

hypertrophic cardiomyopathy

device programming

Wolf-Parkinson-White syndrome

risk stratification

shared decision-making