Chapters Transcript Video Arrythmias in HCM So I have no disclosures uh relevant to the talk. So what is the most common sustained arrhythmia seen in patients with hypertrophic cardiomyopathy? We think of it as ventricular tachycardia or arrhythmias from the bottom chamber, especially um given the scarring that we've seen from MRI, but it's actually atrial fibrillation. So, atrial fibrillation affects about one in five patients diagnosed with AC M and it's younger. Usually we think of atrial fibrillation as patients get older into their sixties and seventies. But in HCM, it's usually at younger ages, it's 40 to 50 years old and it's difficult to manage because these patients have dilated left atrium from the diastolic dysfunction. Um their atria undergo a lot of remodeling. And so that creates a very difficult time for us as a heart failure specialist to manage. But it includes a combination of anti arrhythmic drugs ablation, which is my first love. Um and even avino ablation and pa maker implantations. And the important part, Doctor Battier mentioned is all patients receive anticoagulation. It doesn't matter what your Chad's vas is if you have a diagnosis of atrial fibrillation and HCM because the stroke risk is so high, just like amyloid cardiomyopathy, those patients get anticoagulation. So here is how we think about managing atrial fibrillation in HCM patients. So back in the day, we would do a lot of drugs, beta blockers, rail or dil them because they can help with the left ventricular outflow tract obstruction, um which was previously mentioned, but we really want to achieve rhythm control strategy because they need their atrial kick, maintaining sinus rhythm, improves their symptoms. And so there's different methods on how to control rhythm. You could have drugs. Sotolol, amiodarone being the most common though people have tried to folly as well. Um And we try to avoid fleck and or propafenone given the risk of a black box warning with sudden cardiac arrest associated with those drugs. But if patients have IC DS, their efs normal, not much scarring seen on MRI, you could consider it. Um But then I would say that now catheter ablation and you'll hear more later in the afternoon is moving more first line for most of these therapies as our ablation technology has gotten faster, safer and more effective. Um But if they are a candidate for surgical myectomy, then they should undergo a maze procedure to try to maintain rhythm control strategy. So, here's a longitudinal study where patients were treated with either amiodarone and this was done in 1990 before we even knew catheter revelation was an effective therapy um or conventional rate control strategies with beta blockers, calcium channel blockers or digoxin. And you could see the amiodarone patients, they stay alive, they maintain sinus rhythm. While the conventional strategy, a lot of people, a lot of patients had um side effects, they were switched to amiodarone to try to get maintain cardiac filling and um atrial contractility. Um And so, maintaining sinus rhythm or some kind of rate control strategy in these patients is very important. So there are no randomized control trials uh for catheter ablation in AC M compared to rhythm control therapy. Uh but there are propensity matching, which is uh it's not randomized, but it's as good as we'll get until we have better data. So, in this study, they included 226 patients with ATM and atrial fibrillation. 113 were treated with medical treatment. So combination of anti arrhythmic drugs and rate control ass, then 100 and 13 were treated by a frill. And what you can see from the right is even though there's no mortality benefit or stroke reduction, the P values are all greater than 0.05. They have less a FB occurrences and lower progression rate to permanent atrial fibrillation. And that's important, right? It's not one ablation will work. Two ablations will work. It's about time in a FB and lower progression to what we call permanent atrial fibrillation because we know atrial fibrillation begets atrial fibrillation and the atria undergo remodeling especially when it's not in sinus rhythm. So, on the left is a map that we create with the catheter in the heart using technology, mapping technology with patches on the back of of the patient. Um and purple means healthy tissues. So purple on the left is a normal patient without ATM. And you could see most of the atria are normal. The two things on the side are pulmonary veins on both sides. And you could see on the right is a patient with ATM and they've already developed scarring. So as you go from purple to yellow to green, the green and the yellow are scarring and that atria has already undergone scarring just because of the path of physiology of the mitral regurgitation. Um and the atrial enlargement given the obstruction, the last strategy, if ablation doesn't work, I would say we quote patients that ablation is always be better than medicine. It works about 80% of time and head to head. Multiple New England journal studies have shown ablation is more effective in AC M I would quote patients that the effectiveness of one ablation is 40 to 50%. Not great, not perfect. Uh but sometimes patients may need a second ablation, they may need a third. But what if ablation is not an option for a patient because they have too, too many comorbidities or their end stage atrial fibrillation. This is a study showing the effectiveness of avino ablation. So, disconnecting the top chamber from the bottom and controlling them with a pacemaker. And you could see a lot of patients will improve their New York class Heart class Association. So that dark yellow on the bottom shows a reduction in NYH A class four being the worst and one being the best. A lot of patients will provide a get a big benefit um with a v nodal ablation and pacemaker implantation. And you can see on the right that the rejection fraction does not change. And so, um especially in the era of physiologic pacing, a lot of these patients get a benefit just from their rates being uncontrolled. If their rates going 120 their obstruction is much worse. And so if you don't think they're a candidate for an ablation, I think you should consider avi no ablation and pacemaker. So now what about the other arrhythmias? The worrisome ones people dropping dead from ATM. So we know nonsustained and sustained arrhythmias has happened in about 30% of patients. Sudden death is much, is close to 1% of people and Children and younger adults. And it's more common to have ventricular tachycardia because of scarring and setting up circuits than ventricular fibrillation. And we use risk calculators used to predict need for I CD. I tell patients if you're 70 you have AC M, even if you see nonsustained arrhythmias on a monitoring, you're probably you've survived sudden death so long that you're not gonna need a defibrillator. But if you're, if you're a 30 year old, you have a strong family history, we see scarring, you deserve a defibrillator. And so these are some of flow charts we use in the office and we talk about it. It is a shared decision making. We look at their risk score. If they've had sudden cardiac arrest, it's very easy. Class one I CD is indicated, but we do a shared decision making where the patient's preference is taken into account. And we look at all the risk factors and we say your risk is very low and your risk of having a defibrillator long term is higher than the benefit you may derive from one. Or we say the benefit is much greater and your risk of sudden death is too high to do any of this. And we also do shared decision making on playing sports. If they have a very high sudden risk, we may put in a defibrillator and say you could play sports with the defibrillator. So one of the advances in the field and where this shared decision making has been made easier is the invention of subcutaneous I CD, especially in younger patients. We want to avoid leads in the veins because we can't just pull those wires out. They become fibros. We have to use lasers which have um some risk 1% I would say low risk, but still there's some risk. And so the subcutaneous I CD has removed that risk of transvenous completely where we could just pull it out and the leads not in the heart. And you could see here, they compared 216 patients who wonder when subcutaneous I CD, compare transvenous and subcutaneous I CD did just as well with lower lead complications over follow up 4 to 5 years. And so this has changed the care of younger patients who have if they have a lot of risk factors in younger patients. We prefer the subcutaneous I CD compared to transvenous. These are some of the arrhythmias. We see when patients have hypertrophic cardiomyopathy, you could see the echocardiogram on the left showing that thickened left ventricle. Um the patient had a dual chamber I CD and you could see on the top is the atrial EG MS and on the bottom is the ventricular if you have more stuff on the bottom, compare to top, you know that the ventricle is driving the arrhythmia. And so this is a patient having a lot of ventricular tachycardia. And we get MRI imaging and our imaging colleagues are very helpful at this because it can tell us a couple of things. One is how much scarring do they have because we know in ep that circuits revolve around scars. And so it gives us an idea if you see scarring at the apex, you know, the aneurysm is causing it. That's where I'm going to have to map and ablate um the arrhythmia. But the other information, it gives us, especially in hyper, in apical HCM. Is, is there a clot, sometimes these patients have aneurysms and clots can develop at the apex of these. And so if I'm putting a catheter there, the patient could be at risk of stroke. And so doing this planning with our imaging colleagues where we get the MRI the day before or the day of the ablation wrote, helps me risk ratify whether I need um to do anything else or think about a sentinel protection device and things like that before I go after it with catheters. So here are long term outcomes of combined epicardial and endocardial ablation of VT related to AC M. Um The most common locations are in the apex and you could see the scarring again on the right map. The red is the scarring and that's at the apex or uh the bottom of the heart. And you could see purple is normal. So most of these circuits will develop around that scar, but you could have some scarring also in the inter lateral base. Um And it requires epicardial ablation as well. So, not just inside the heart, we have to gain access through a needle outside of the heart um and burn on the outside to get full transmural um to prevent further arrhythmias. But it is an effective treatment for ventricular tachycardia, especially in younger patients where we want to avoid the long term risks associated with the amiodarone. Um And then I'll just end with emerging technologies. I know Doctor Battier mentioned all of these newer drugs. What he won't mention is the price associated with Mava Campton or all of these newer things. And my patients, you know, they tell me day in, day out, you know how expensive Eliquis is or River Roan or any of these newer Dre agents. So this is a case, Doctor Summers um asked us to do and we got permission and this is the team approach we do which at Sana, which is really important. So one of the places Emory I think was the first in the world to do what we call bipolar ablation, ablate from one catheter to another. Usually we do unipolar ablation where we put patches on the patient and just burn through the patches. So it's dispersive. But doctor Summers asked this patient who had a hypertrophic um septum from just LVH and 81 year old. No option. Surgery turned her down. Uh no targets for um alcohol. He asked if we could burn the septum and reduce it so the patient could get a mitral valve that he would later do. So I took uh I read the paper, it seemed OK to do. We designed a catheter. I took one of texts from the EP lab. We went to engineering, we soldered together and we did the case and the patient got a nice reduction in septal therapy. Um There are people doing this in Mexico and third world countries uh because they can't afford Mavic Campton gene therapy is not going to be an option in India, Mexico and these third world countries. So if you're doing catheters, if you're taking out WPW or ablating PV CS, you could do one catheter next and reduce the septum, especially if alcohol, septal ablation is not an option. And so my conclusions are arrhythmias, both from the atrium and ventricle are common in patients with AC M, maintaining sinus rhythm will improve their quality of life and heart function. It's a safe and effective therapy to prevent recurrences of a atrial fibrillation and ventricular tachycardia. But you know, it's not gonna be a cure. And I tell all my patients with a FB, you're managing the condition lifelong. It's not like appendicitis where we can remove the appendix. It's just they may, may need multiple ablations and you may require advanced techniques for VTU whether it's bipolar ablation or epicardial ablation. And then we, we'll hear about pulse field ablation from one of my colleagues later, but it'll hold a promising uh and emerging therapies. Our old catheters had a lot of fluid associated with them. Patients would get heart failure, they would be under anesthesia longer with pulse field ablation. Our times are shorter. There's no fluid patients are going home within a couple of hours of the procedure. And so I think it'll be important especially in patients where we're trying to avoid heart failure. Thank you. Published November 14, 2024 Created by Related Presenters Divyang Patel, M.D. Sentara Cardiology Specialists View Full Profile
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