Selected Podcast
Current Management of Ventricular Arrhythmias
Ventricular tachycardia (VT) is a life-threatening arrhythmia that requires a comprehensive treatment approach unique to a patient’s comorbidities and heart condition. As electrophysiologist William Maddox, MD, explains, patients with a structurally normal heart can often manage VT with various medications, while those with myopathies also require defibrillator (ICD) implantation and catheter ablation. He explains the advances in catheter ablation technology that have resulted in success rates as high as 90%, depending on the patient’s substrate metabolism. Research has shown that early referral for catheter ablation reduces a patient’s number of ICD shocks and improves outcomes.
Featuring:
Learn more about William Maddox, MD
Release Date: July 28, 2022
Expiration Date: July 27, 2025
Disclosure Information:
Planners:
Ronan O’Beirne, EdD, MBA
Director, UAB Continuing Medical Education
Katelyn Hiden
Physician Marketing Manager, UAB Health System
The planners have no relevant financial relationships with ineligible companies to disclose.
Faculty:
William Maddox, MD
Assistant Professor in Cardiology, Electrophysiology
Dr. Maddox has no relevant financial relationships with ineligible companies to disclose.
There is no commercial support for this activity.
William Maddox, MD
Dr. Maddox is a clinical cardiac electrophysiologist committed to delivering exceptional healthcare through dedication to patients and their families. He strives to provide compassionate care, through personalized education and open communication, wishing to inspire hope and well-being in all his patients.Learn more about William Maddox, MD
Release Date: July 28, 2022
Expiration Date: July 27, 2025
Disclosure Information:
Planners:
Ronan O’Beirne, EdD, MBA
Director, UAB Continuing Medical Education
Katelyn Hiden
Physician Marketing Manager, UAB Health System
The planners have no relevant financial relationships with ineligible companies to disclose.
Faculty:
William Maddox, MD
Assistant Professor in Cardiology, Electrophysiology
Dr. Maddox has no relevant financial relationships with ineligible companies to disclose.
There is no commercial support for this activity.
Transcription:
Melanie Cole: Welcome to UAB MedCast. I'm Melanie Cole. And joining me to discuss current management of ventricular arrhythmias is Dr. William Maddox. He's a cardiac electrophysiologist and an Associate Professor at UAB Medicine.
Dr. Maddox, it's a pleasure to have you join us today. As we get into this topic, speak first about the prevalence of ventricular tachycardia. It could be a dangerous and many times deadly arrhythmia. Speak about what you've been seeing in the trends.
Dr. William Maddox: Sure. Thank you for having me. So ventricular tachycardia is an arrhythmia that we're seeing with an increasing prevalence in our population here, specifically in the population as a whole. As our patients have many comorbid conditions like hypertension, diabetes, and especially coronary artery disease and heart failure, one of the things that goes along with that are ventricular arrhythmias. And so, especially in the south here where we have quite a bit of patients with coronary disease, we see quite a bit of atrial fibrillation. And as the population ages, I anticipate that that's going to continue to get more prevalent.
Melanie Cole: I agree with you. And as we're talking to other providers, speak about the clinical presentation, Dr. Maddox. Some of the symptoms of the hemodynamically unstable ventricular tachycardia, what are they looking for?
Dr. William Maddox: Hemodynamically unstable VT is truly a medical emergency. These patients are many times presenting with chest pain, shortness of breath. It may be with syncope or pre-syncopal symptoms, and usually they're presenting to you in an emergency medical setting. These patients need intervention very quickly or they can decompensate and it can be a life-threatening arrhythmia.
Melanie Cole: Is there screening, Dr. Maddox? And if so, when would that be indicated?
Dr. William Maddox: Screening is tough in these patients. Certainly, we understand that in patients with structural heart disease, there are patients who are at increased risk for ventricular arrhythmia and ventricular tachycardia. And generally, that's going to be patients with ejection fractions of less than 35%, either in the face of coronary disease and ischemic cardiomyopathy or in dilated or non-ischemic cardiomyopathies.
And so in those patients, as you would for management of their heart failure, you're going to get routine echocardiograms as well as EKGs. But screening in the asymptomatic patient isn't something that we would recommend outside of the general EKG that you're going to get in the course of just their general treatment. There certainly are other reasons why people may have ventricular tachycardia, including some of the channelopathies, as well as hypertrophic cardiomyopathy or other things. And in those patients, it can be important to screen the patients either with EKGs or with longer telemetry monitoring, especially if they're having any symptoms of either syncope or pre-syncope or if they're presenting with palpitations at all.
Melanie Cole: I understand, Dr. Maddox, this is a pretty broad discussion that we're having. Whether we're talking about electrical circulatory or structural disorders, I'd like you to give sort of an overview, brief overview, of therapies available. You can start with medical interventions and move on from there. But give us a brief overview of what you do.
Dr. William Maddox: So, VT, which is our acronym in electrophysiology and how we refer to it, there's quite a variety of patients who present with ventricular tachycardia and depending on what their underlying cardiac comorbidities might be, the approach might be very different. In a patient who has what we call idiopathic ventricular tachycardia, which would we be VT in an otherwise structurally normal heart, these patients many times can respond well to medical therapy with beta blockers, calcium channel blockers, particularly verapamil in some patients with right ventricular outflow tract tachycardia. Our antirrhythmic drugs in patients with otherwise normal hearts are pretty wide open. That would include the 1C antirrhythmics like flecainide or propafenone, sotalol, Tikosyn some and, of course, amiodarone is kind of 800-pound gorilla that is pretty darn effective, but has a whole host of long-term problems with multiple organ systems. And so we try to avoid that as we can.
In patients who have structural heart disease, and that's kind of an umbrella term where I'm talking about patients with both non-ischemic and ischemic cardiomyopathy, as well as hypertrophic myopathy, or valvular heart disease that might be significant, those patients generally are at a higher risk of sudden cardiac death with ventricular tachycardia. And our treatment modalities are going to be more important in both primary prevention for patients who are at high risk and in secondary prevention for patients who have already presented with VT or possibly sudden cardiac arrest. That from a medical medication standpoint can certainly include the antirrhythmics. And many times, we're trying to decrease the burden of arrhythmia and stop someone from getting shocked if they have a defibrillator. One of the main stage of treatment for VT in a patient with structural heart disease would be an implantable cardiac defibrillator. This is something that's quite common now and that we see. We have both transvenous systems that can be implanted in either the left or the right subclavicular area on the anterior chest wall. And there's also a subcutaneous ICD that can be implanted in the mid-axillary space under the left arm with a lead that's tunneled under the skin, and then lies just lateral to the sternum.
In patients who have ventricular tachycardia that has been recalcitrant to medical therapy, these patients are excellent candidates for catheter ablation. And this is a therapy that has certainly become more favorable as our tools for being able to map the ventricular tachycardia circuits in the heart have gotten so much better and our delivery tools for energy to the heart to be able to ablate and cauterize these areas that are problematic has gotten better. It's something that's quite common now. And in any given week, I'll probably do three to four VT ablations. I know that I'll do two tomorrow. The success rate of VT ablation can be heterogeneous depending on what the patient's substrate is with success rates as high in the mid to high 90% in patients with idiopathic VT down to patients with infiltrative cardiomyopathies or hypertrophic cardiomyopathy or arrhythmogenic dysplasia, where those patients have a high rate of recurrence.
Melanie Cole: What about secondary prevention of VT?
Dr. William Maddox: So the mainstay of treatment for secondary prevention in patients with any structural heart disease is that we want to get a defibrillator in them. These patients many times have presented with aborted sudden cardiac arrest, either to an emergency setting or occasionally they may show up in our clinics. And we'll intervene acutely on the arrhythmia, but then we want to prevent the next episode. And so these patients will all be offered an implantable defibrillator. And then these defibrillators have the ability to deliver energy and shock the patient out of an arrhythmia should they ever have one. And the transvenous systems also have the ability to be able to use algorithms to pace the patient out of ventricular tachycardia if they have it with a pretty high level of success.
For stable ventricular arrhythmias or monomorphic ventricular arrhythmias, antitachycardia pacing can be successful 50 to 70% of the time. And this limits the amount of shocks that the patient gets. And many times they may have VT and not ever know that they had an arrhythmia and show up in my clinic for routine followup and we note that they'd had an arrhythmia sometimes two or three months earlier.
Melanie Cole: Dr. Maddox, while we've been talking about anti-arrhythmic therapy and implantable cardioverter defibrillators, all of these things you're discussing, these are the, mainstays of therapy and well managed by someone such as yourself, a cardiac electrophysiologist, there are many other facets in the care of these patients, such as heart failure management, treatment of comorbidities that you were mentioning, aesthetic interventions, where expertise of other specialists is really essential for optimal patient care. Can you speak about that coordinated team approach and how it's essential to achieve the best possible outcomes for these complex patients?
Dr. William Maddox: Sure. I think that that's incredibly important in our patient population that seems to be getting more complex by the day. As an example, my clinic is on Tuesdays and Thursdays and two doors down are my heart failure colleagues. And we work hand in hand in treating these patients. And there's many times in clinic that they'll grab me and ask me to come in and interrogate a device and make some changes or make some recommendations on anti-arrhythmic drugs on the other hand.
When I see patients in my clinic and they obviously are having difficulty with fluid management or heart failure symptoms, it's not infrequent for me to find my heart failure colleagues, and talk about seeing them that day and helping me manage their loop diuretics or other things to help manage their heart failure. I think that VT from an electrophysiologist standpoint is an electrical problem, but in the patients in the broader sense, this certainly has everything to do with heart failure management and the hemodynamics to help make sure that the patient doesn't have either more VT or if they do have VT, that they're better able to tolerate it.
Melanie Cole: And that really is the main point, isn't it? So I'd like you to wrap up by telling other providers the importance of early referral for VT ablation, how it can reduce ICD shocks, improve patient outcomes, including mortality. Wrap it up with your best advice and key takeaways.
Dr. William Maddox: Sure. So I think that many times we see VT in my specialty and especially at a tertiary care center, I've seen them and they've been managed with antirrhythmic drugs for a significant amount of time with multiple shocks. And by the time they get to me, they've been shocked multiple times and sometimes has significant hemodynamic consequences from their untreated arrhythmia.
And I'd like everybody to think about the first time that you think about referring a patient to your electrophysiologist for consideration of ablation should be the first time you see VT. And it doesn't mean that your EP is going to take everybody to the lab, but that's the first time I want to start having the conversation with the patient. And there's been recent data that have shown that patients have better outcomes with less shocks and live longer and stay out of the hospital if we intervene on these arrhythmias sooner, rather than waiting until we have failure of multiple anti-arrythmics.
Melanie Cole: That's a great point. And thank you so much, Dr. Maddox, for joining us today, sharing your expertise for other providers with us. And a physician can refer a patient to UAB Medicine by calling the MIST line at 1-800-UAB-MIST or you can always visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast. For updates on the latest medical advancements, breakthroughs and research, follow us on your social channels. I'm Melanie Cole.
Melanie Cole: Welcome to UAB MedCast. I'm Melanie Cole. And joining me to discuss current management of ventricular arrhythmias is Dr. William Maddox. He's a cardiac electrophysiologist and an Associate Professor at UAB Medicine.
Dr. Maddox, it's a pleasure to have you join us today. As we get into this topic, speak first about the prevalence of ventricular tachycardia. It could be a dangerous and many times deadly arrhythmia. Speak about what you've been seeing in the trends.
Dr. William Maddox: Sure. Thank you for having me. So ventricular tachycardia is an arrhythmia that we're seeing with an increasing prevalence in our population here, specifically in the population as a whole. As our patients have many comorbid conditions like hypertension, diabetes, and especially coronary artery disease and heart failure, one of the things that goes along with that are ventricular arrhythmias. And so, especially in the south here where we have quite a bit of patients with coronary disease, we see quite a bit of atrial fibrillation. And as the population ages, I anticipate that that's going to continue to get more prevalent.
Melanie Cole: I agree with you. And as we're talking to other providers, speak about the clinical presentation, Dr. Maddox. Some of the symptoms of the hemodynamically unstable ventricular tachycardia, what are they looking for?
Dr. William Maddox: Hemodynamically unstable VT is truly a medical emergency. These patients are many times presenting with chest pain, shortness of breath. It may be with syncope or pre-syncopal symptoms, and usually they're presenting to you in an emergency medical setting. These patients need intervention very quickly or they can decompensate and it can be a life-threatening arrhythmia.
Melanie Cole: Is there screening, Dr. Maddox? And if so, when would that be indicated?
Dr. William Maddox: Screening is tough in these patients. Certainly, we understand that in patients with structural heart disease, there are patients who are at increased risk for ventricular arrhythmia and ventricular tachycardia. And generally, that's going to be patients with ejection fractions of less than 35%, either in the face of coronary disease and ischemic cardiomyopathy or in dilated or non-ischemic cardiomyopathies.
And so in those patients, as you would for management of their heart failure, you're going to get routine echocardiograms as well as EKGs. But screening in the asymptomatic patient isn't something that we would recommend outside of the general EKG that you're going to get in the course of just their general treatment. There certainly are other reasons why people may have ventricular tachycardia, including some of the channelopathies, as well as hypertrophic cardiomyopathy or other things. And in those patients, it can be important to screen the patients either with EKGs or with longer telemetry monitoring, especially if they're having any symptoms of either syncope or pre-syncope or if they're presenting with palpitations at all.
Melanie Cole: I understand, Dr. Maddox, this is a pretty broad discussion that we're having. Whether we're talking about electrical circulatory or structural disorders, I'd like you to give sort of an overview, brief overview, of therapies available. You can start with medical interventions and move on from there. But give us a brief overview of what you do.
Dr. William Maddox: So, VT, which is our acronym in electrophysiology and how we refer to it, there's quite a variety of patients who present with ventricular tachycardia and depending on what their underlying cardiac comorbidities might be, the approach might be very different. In a patient who has what we call idiopathic ventricular tachycardia, which would we be VT in an otherwise structurally normal heart, these patients many times can respond well to medical therapy with beta blockers, calcium channel blockers, particularly verapamil in some patients with right ventricular outflow tract tachycardia. Our antirrhythmic drugs in patients with otherwise normal hearts are pretty wide open. That would include the 1C antirrhythmics like flecainide or propafenone, sotalol, Tikosyn some and, of course, amiodarone is kind of 800-pound gorilla that is pretty darn effective, but has a whole host of long-term problems with multiple organ systems. And so we try to avoid that as we can.
In patients who have structural heart disease, and that's kind of an umbrella term where I'm talking about patients with both non-ischemic and ischemic cardiomyopathy, as well as hypertrophic myopathy, or valvular heart disease that might be significant, those patients generally are at a higher risk of sudden cardiac death with ventricular tachycardia. And our treatment modalities are going to be more important in both primary prevention for patients who are at high risk and in secondary prevention for patients who have already presented with VT or possibly sudden cardiac arrest. That from a medical medication standpoint can certainly include the antirrhythmics. And many times, we're trying to decrease the burden of arrhythmia and stop someone from getting shocked if they have a defibrillator. One of the main stage of treatment for VT in a patient with structural heart disease would be an implantable cardiac defibrillator. This is something that's quite common now and that we see. We have both transvenous systems that can be implanted in either the left or the right subclavicular area on the anterior chest wall. And there's also a subcutaneous ICD that can be implanted in the mid-axillary space under the left arm with a lead that's tunneled under the skin, and then lies just lateral to the sternum.
In patients who have ventricular tachycardia that has been recalcitrant to medical therapy, these patients are excellent candidates for catheter ablation. And this is a therapy that has certainly become more favorable as our tools for being able to map the ventricular tachycardia circuits in the heart have gotten so much better and our delivery tools for energy to the heart to be able to ablate and cauterize these areas that are problematic has gotten better. It's something that's quite common now. And in any given week, I'll probably do three to four VT ablations. I know that I'll do two tomorrow. The success rate of VT ablation can be heterogeneous depending on what the patient's substrate is with success rates as high in the mid to high 90% in patients with idiopathic VT down to patients with infiltrative cardiomyopathies or hypertrophic cardiomyopathy or arrhythmogenic dysplasia, where those patients have a high rate of recurrence.
Melanie Cole: What about secondary prevention of VT?
Dr. William Maddox: So the mainstay of treatment for secondary prevention in patients with any structural heart disease is that we want to get a defibrillator in them. These patients many times have presented with aborted sudden cardiac arrest, either to an emergency setting or occasionally they may show up in our clinics. And we'll intervene acutely on the arrhythmia, but then we want to prevent the next episode. And so these patients will all be offered an implantable defibrillator. And then these defibrillators have the ability to deliver energy and shock the patient out of an arrhythmia should they ever have one. And the transvenous systems also have the ability to be able to use algorithms to pace the patient out of ventricular tachycardia if they have it with a pretty high level of success.
For stable ventricular arrhythmias or monomorphic ventricular arrhythmias, antitachycardia pacing can be successful 50 to 70% of the time. And this limits the amount of shocks that the patient gets. And many times they may have VT and not ever know that they had an arrhythmia and show up in my clinic for routine followup and we note that they'd had an arrhythmia sometimes two or three months earlier.
Melanie Cole: Dr. Maddox, while we've been talking about anti-arrhythmic therapy and implantable cardioverter defibrillators, all of these things you're discussing, these are the, mainstays of therapy and well managed by someone such as yourself, a cardiac electrophysiologist, there are many other facets in the care of these patients, such as heart failure management, treatment of comorbidities that you were mentioning, aesthetic interventions, where expertise of other specialists is really essential for optimal patient care. Can you speak about that coordinated team approach and how it's essential to achieve the best possible outcomes for these complex patients?
Dr. William Maddox: Sure. I think that that's incredibly important in our patient population that seems to be getting more complex by the day. As an example, my clinic is on Tuesdays and Thursdays and two doors down are my heart failure colleagues. And we work hand in hand in treating these patients. And there's many times in clinic that they'll grab me and ask me to come in and interrogate a device and make some changes or make some recommendations on anti-arrhythmic drugs on the other hand.
When I see patients in my clinic and they obviously are having difficulty with fluid management or heart failure symptoms, it's not infrequent for me to find my heart failure colleagues, and talk about seeing them that day and helping me manage their loop diuretics or other things to help manage their heart failure. I think that VT from an electrophysiologist standpoint is an electrical problem, but in the patients in the broader sense, this certainly has everything to do with heart failure management and the hemodynamics to help make sure that the patient doesn't have either more VT or if they do have VT, that they're better able to tolerate it.
Melanie Cole: And that really is the main point, isn't it? So I'd like you to wrap up by telling other providers the importance of early referral for VT ablation, how it can reduce ICD shocks, improve patient outcomes, including mortality. Wrap it up with your best advice and key takeaways.
Dr. William Maddox: Sure. So I think that many times we see VT in my specialty and especially at a tertiary care center, I've seen them and they've been managed with antirrhythmic drugs for a significant amount of time with multiple shocks. And by the time they get to me, they've been shocked multiple times and sometimes has significant hemodynamic consequences from their untreated arrhythmia.
And I'd like everybody to think about the first time that you think about referring a patient to your electrophysiologist for consideration of ablation should be the first time you see VT. And it doesn't mean that your EP is going to take everybody to the lab, but that's the first time I want to start having the conversation with the patient. And there's been recent data that have shown that patients have better outcomes with less shocks and live longer and stay out of the hospital if we intervene on these arrhythmias sooner, rather than waiting until we have failure of multiple anti-arrythmics.
Melanie Cole: That's a great point. And thank you so much, Dr. Maddox, for joining us today, sharing your expertise for other providers with us. And a physician can refer a patient to UAB Medicine by calling the MIST line at 1-800-UAB-MIST or you can always visit our website at uabmedicine.org/physician. That concludes this episode of UAB MedCast. For updates on the latest medical advancements, breakthroughs and research, follow us on your social channels. I'm Melanie Cole.