Treatment Advances for Heart Rhythm Disorders

One potential effect of heart rhythm disorders known as arrhythmias is sudden cardiac arrest, which causes the heart to stop beating and can cause death in minutes.

UVA is among the first hospitals in the U.S. to offer a new device for sudden cardiac arrest – learn more from a UVA expert in heart rhythm disorders.
Treatment Advances for Heart Rhythm Disorders
Featured Speaker:
Dr. Andrew Darby
Dr. Andrew Darby is board-certified in internal medicine, cardiovascular disease and cardiac electrophysiology. He specializes in treating patients with heart rhythm disorders.


Transcription:
Treatment Advances for Heart Rhythm Disorders

Melanie Cole (Host): What are heart rhythm disorders and what are some of the new exciting treatment advances for heart rhythm disorders. My guest is Dr. Andrew Darby. He is board certified in internal medicine, cardiovascular disease, and cardiac electrophysiology. Welcome to the show, Dr. Darby. Tell us what are heart rhythm disorders?

Dr. Andrew Darby (Guest): Hi. Good morning. Thank you. Heart rhythm disorders are essentially electrical abnormalities of the heart which affect the timing of the heart rate and heart rhythm and they can either make the heart beat too quickly or too slowly. Some are completely benign, but they can cause bothersome symptoms whereas others can increase the risk of stroke and that’s primarily a rhythm called atrial fibrillation which is a very common heart rhythm disorder in adults and still other heart arrhythmias can actually be life-threatening and these are the ventricular arrhythmias which are abnormal rhythms that arise from the lower chambers of the heart and these arrhythmias include ventricular tachycardia and ventricular fibrillation.

Melanie: Typically doctor, treatment for, you know atrial fibrillation as you said is becoming more common. People go on Coumadin and blood thinners, all of these things. What is after that, if those things are not working for them? Tell us about some of the new treatment advances for heart rhythm disorders.

Dr. Darby: Sure, so for atrial fibrillation, there are actually a lot of exciting therapies for the patients who have symptomatic atrial fibrillation meaning they feel their heart racing, they feel their heart beating irregularly. We have medications we can use to try to control the heart rhythm to try to keep patients in normal rhythm. We also have procedures that we can do called catheter ablation where we can minimally invasively insert catheters into the heart to identify the areas where the arrhythmia is coming from and basically burn those areas out and eliminate them to try to maintain a normal rhythm. You mentioned Coumadin which is a blood thinner. One of the main risks with atrial fibrillation is that it can increase the risk of stroke. Over the past few years, a number of new medications have been developed as alternative to Coumadin. These medications are nice in that they don't involve any blood testing which Coumadin requires. They tend to be very reliable on how they work that can be very effective and relatively safe. For patients who can't take blood thinners, there are number of new exciting alternatives to protect patients from a stroke. There are procedures that we can do to essentially seal off the part of the heart where clots tend to form and one of those procedures can be done through by inserting catheters into their veins in the leg and one of the procedures can be done actually by accessing the space around the heart and actually sealing off the place where the clots form, so for the patients who can't take blood thinners, those therapies are nice alternative. For other arrhythmias such as the ventricular arrhythmias like ventricular tachycardia, we have a lot of exciting new therapies to treat those as well. There is catheter ablation just like I mentioned for atrial fibrillation. There is a catheter ablation procedure, we could do to treat that as well as implantable defibrillators which are heart rhythm devices that monitor the heart rhythm and restore normal heart rhythm should patients develop one of these life-threatening heart arrhythmias.

Melanie: So, Dr. Darby speak about the subcutaneous implantable cardioverter defibrillator that's a lot to say, but this is a new exciting treatment, so tell the listeners what that is?

Dr. Darby: Sure, so let me first start by talking about the standard defibrillator which up until now has been the only version available, so the previously available defibrillators are systems that we call transvenous defibrillators and what that means is there's not only a defibrillator unit which is something that we implant under the skin in the chest, but there's a wire that we place into the heart to monitor the heart rhythm, so standard defibrillators as we have had available involve inserting one or more wires into the heart and in the way, we implant these devices as we make a incision in the upper part of the chest. The defibrillator device, the actual defibrillator unit, is placed under the skin and then more and more wires are placed into a vein in the upper part of the chest and through that vein, we are able to pass these wires into the heart and traditionally, the wires have been the weakest link or the weakest part of the defibrillator system, so the wires are actually secured to the heart muscle and so they move with each heartbeat and you can imagine if someone has an average heart rate of 70 or 80 beats per minute that's about hundred thousand heartbeats in a day and these devices are supposed to last for years and years and years and decade and that’s a lot of wear and tear and lot of stress on these wires over time and one problem with the standard defibrillator is that the wire can sometimes fracture, can break which can lead to other issues for the patient and so the subcutaneous defibrillator has been developed as an alternative to this and hopefully will be a more durable device and so the biggest differences I would say between the subcutaneous device and the defibrillators that we have traditionally had are that the subcutaneous device is as the name implies, completely subcutaneous, so it does not involve placing anything inside the bloodstream or anything inside the heart. The way we implant it is we make a small incision on the side of the chest for the defibrillator unit to fit in and then two smaller incisions are made along the left side of the breastbone and those smaller incisions are what we use to actually implant the wire that’s attached to the defibrillator, so there is a wire just like we have with standard defibrillators, but this wire is just subcutaneous, it’s just under the skin. That wire essentially is the antenna for the device. That’s how the device monitors the heart rhythm and helps to detect whether the patient is going into a dangerous heart arrhythmia.

Melanie: That is so cool Dr. Darby. Who is a candidate for this?

Dr. Darby: It’s a good question. I think anyone being considered for a defibrillator is a potential candidate for subcutaneous device. I think anyone who has had, has blood vessel problems where we might have difficulty accessing the heart or placing the standard transvenous leads into the heart, it would be a good candidate for subcutaneous device. Patients with infectious issues, if the patients have had bloodstream infections or have had recurrent bloodstream infections, we don't want to implant something in the body that could potentially become infected, so the subcutaneous device is out of the bloodstream, so it's nice in that regard. I think especially for young patients, patients who might have the device for years and years and years for decades, with them the subcutaneous device is going to be much more durable because we don't run to the issues with the lead or the wire or the antenna fracturing. I think one thing that should be emphasized is who might not be a candidate for the subcutaneous device, so one limitation of the subcutaneous device is that it cannot function as a pacemaker, so the standard defibrillators that involve the wire going into the heart like I mentioned, those devices can also be pacemaker, so for patients who have a slow heart rate, who also require cardiac pacing, meaning they require some assistance to the device to maintain a normal heart rate to speed their heart rate up, that cannot be done with the subcutaneous device, so the patients who require both a defibrillator which would protect them from life-threatening arrhythmias and the patients who require a pacemaker, patients who require both would be better served by the standard defibrillator. Patients who don't require any pacing assistance would be perfectly fine with the subcutaneous device.

Melanie: Dr. Darby and just the last minute please, why should patients come to UVA for heart rhythm diagnosis and treatment?

Dr. Darby: Very good question. I think every patient should come to UVA, but I'm biased. I think we have very well-trained, highly experienced staff both as far as physicians as well as our non-physician staff to support us in these procedures. The University of Virginia was actually the first hospital in the State of Virginia to have an electrophysiologist about 30 years ago, Dr. John DiMarco and we have grown and grown and grown our program over the past few decades and we have the most experience of any program in the state. We have done thousands and thousands and thousands of catheter ablation procedures and device implants and I think that experience matters and another nice thing about being a University Academic Medical Center is that we often have exposure and are given access to these new technologies sooner than other hospitals are and so, we will be the first hospital in Central Virginia to be implanting the subcutaneous defibrillator and we will all have access and do have access to other ablation technologies and other device technologies that other hospitals don't have and so I think for those reasons the experience and the access to new better technologies, I think these are some of the big reasons to come to the University of Virginia.

Melanie: Thank you so much. That's great information. You are listening to UVA Health System Radio. For more information, you can go to uvahealth.com. This is Melanie Cole. Thanks for listening.