Baptist Health Electrophysiologist, Dr. Venkata Sagi, MD talks about a new wireless and leadless pacemaker that is saving many heart patients.
Interview conducted by Ivanhoe Broadcast News in 2022.
Tell me about how pacemakers affect the heart when it comes to AFib.
SAGI: In patients who have atrial fibrillation, which is the irregular rhythm coming from the top chambers, they have lot of scar tissue. That is the culprit why they have atrial fibrillation and the electrical signals originate in the top chambers of the heart as well. The scar tissue has no unique predisposition to affecting only certain parts of the top chambers. It usually affects many parts including the electrical system in the top chambers where the normal pacemaker is located. When these pacemaker cells are overwhelmed by the scar tissue, the normal pacemaker tends to become sluggish, meaning, slower and slower. Usually it’s a process of aging, as one gets older. This is more likely to be prevalent and more likely to be manifesting with symptoms related to slow heartbeat.
Such as?
SAGI: Patients experience fatigue, tiredness, lightheadedness, dizziness, inability to meet the needs of daily life, for the reason that when we are active the heart rate has to go up to keep up with that activity. In these patients, the heart rate does not increase with activity or it’s slow all the time.
Does it come on suddenly and affect people in a bacd way?
SAGI: It is not abrupt, it is gradual in most cases, but it can be abrupt in some patients.
Do most people confuse it for just age?
SAGI: That is why people present very late, sometimes attributing the symptoms to old age. We are very specific when we ask the patient to tease out what their symptoms are. We try to ask questions like, “How did you feel six months ago? How do you feel now? Are you able to do the things that you use to do six months ago?” They don’t come to you telling you that there is something wrong sometimes. They attribute that to age as you said. They say, “I’m getting older and this is probably what it looks like when I get older.” The continue confining themselves to lesser and lesser activities with time. Sometimes we have to ask leading questions to get the necessary information because obviously, the purpose of the pacemaker is only to improve the quality of life. It is not a device that would make them live any longer. If they have it, it’s not like they’re going to live longer. If they don’t have it, they’re going to die sooner. That is not the purpose of majority of the pacemakers that we do; it’s the quality of life improvement. Most often it is their children or their loved ones who are more likely to bring up the symptoms as opposed to the patient themselves.
Can you tell me what can go wrong with the leads on a pacemaker?
SAGI: Leads are essentially the wire that connects the pacemaker battery to the heart and is the weakest link in the whole system. The leads are made up of cables, just like your electrical cables. There is a positive anode, negative cathode that are intertwined. That is the weakest link because they can fracture, they can break, and the insulation can fail. They can get dislodged in the first six to eight weeks. They are not firmly attached, so they can fall apart. They can get crushed in the chest. Between your collarbone and the rib cage, the space is tight in some patients, and these crush injuries lead to abrupt failure of the pacing system, and infections if a patient develops a bloodstream infection for any reason. Dental infection spreading into the heart is a fairly common thing. These infections have a tendency to hide in these metallic objects, whether it’s the pacemaker wires or whether it’s any foreign material inside the body, tends to be a safe haven for these infections. It would become extremely difficult to get rid of these infections. Sometimes the only way to cure the patient off the infection is to remove those pacemaker wires completely. That is significantly risky proposition because these wires sometimes stay in the patient for decades and taking them out, which have become part of their body for the past 10 years is a very risky proposition and can lead to significant adverse outcome to the patient. To avoid this is the reason why this technology called leadless pacemakers has become popular, and we are at this point right now because of that weakest link.
They have to do surgery for a pacemaker, correct?
SAGI: You have to make a tiny incision. You have to make a pocket at least to accommodate the device this big, at least a size of a good size of wristwatch.
Tell me about this new pacemaker.
SAGI: The advantages of this new leadless pacemaker compared to the already existing leadless pacemakers that are approved by the FDA is a step up from the one that is already existing in many ways. One advantage is that these pacemakers are in a dormant state when they come in the package and they need to be woken up. This pacemaker is woken up once it’s attached to the patient’s heart. However this pacemaker can be woken up even before the physicians can cross into the heart valves and put the pacemaker they’re woken up when they are placed inside the heart. The advantage is that most often the maneuvering of these pacemakers inside the heart itself can cause complete electrical blockage and there could be what we call a systole or no heartbeat just because of the manipulating of these devices. The advantage of this system is it’s awaken and the moment it comes in contact with the heart, it’s already working as a pacemaker right away, unless the predecessor technology, which needs to be programmed. That takes time and that could be a problem. The other advantages of this system are that these are retrievable. This is the only system that is being tested. With the existing FDA approved device you have no choice but to leave the other one alone and give the patient a new device. This new technology that is not going to be necessary, we can safely remove that and put a new one in the heart.
How do you remove it?
SAGI: This technology has something called active fixation as opposed to the existing one called passive fixation. Active fixation means that these pacemakers have a screw at the end. We turn it to fix the pacemaker to the heart, and we unscrew it when we have to take it out. It is almost like changing your light bulb by rotating and removing it. We hope this will be as simple as that.
Are all pacemakers getting this? Are all these pieces like that?
SAGI: That is the other advantage of this new technology. The technology we have that is approved by the FDA, is a pacemaker that is only placed in one chamber of the heart, the lower chamber of the heart, the ventricle. This means that the patients who have various other kinds of electrical problems, especially originating in the sinus node or those in the top chamber of the heart, is not going to be that useful. The advantage of this new technology is that there are two separate pacemakers that are implanted, one in the bottom chamber, one in the top chamber. These two devices are communicating with each other on a regular basis to coordinate the electrical activity between the top and the bottom. This means the patient should have a normal electrical conduction or at least mimic the normal electrical conduction and provide the activity to be synchronous top and bottom chambers in a synchronized fashion. This coordination is important to help the patient’s quality of life as well. Whereas the existing technology may not be able to provide that accurate synchronization between the top and the bottom because it is only placed in the bottom chamber.
When you see patients who get this, do you see an immediate change in their quality of life?
SAGI: It depends on the need. For example, like any area of medicine, the sicker and the patient, the greater the benefit of any treatment we deliver to the patient. Similarly in this scenario, the patient comes to us with an advanced problem and very slow heartbeat. They will find a remarkable improvement in their quality of life immediately. On the other hand, there could be patients who may need it, but not all the time. They would pass out, but their electrical system is working okay for the most part but not working at certain times. Those patients may not notice an immediate benefit, but over time, they will notice that they’re not experiencing the passing out or symptoms. It depends on why the pacemakers are implanted. There are a group of patients who will notice a dramatic difference. It’s a day and night, and they are very thankful that they had made an improvement in the quality of life.
You are in phase one right now?
SAGI: Initially the testing was done with a single chamber, which means one pacemaker in the bottom chamber that is already passed the approval of the FDA. The purpose of the current study is to understand the effectiveness of the pacemaker in the top chamber, and also to understand the effectiveness of the communication between these two. Part of it is already approved and part of it is waiting for approval. This is the last phase of the clinical trial and we expect the completion of the enrollment within the next few days and the last few patients are being enrolled within the next two weeks. That completes the implementation phase. The next 10 months is going to be the follow up phase. At the end of 10 months, the FDA may give their approval based on the safety profile.
Do you think in five years from now, the leads will be gone and this will be standard of care?
SAGI: It could be the standard of care because this would help patients get back to their lifestyle immediately. Unlike the traditional pacemaker that restricted them not to do anything with their left hand or the right hand depending on where we place it. This one requires at most eight hours of rest to return to normal activity. This will help our elderly patients who are very dependent on their arms for their mobility. Old pacermakers are also made to wear as a sling, making them limiting. The only thing that helps us make that claim that this is likely to become mainstream is the safety profile. Current pacemakers have a battery life of 10 years. We have to demonstrate the safety of taking these out over a long period of time.
Does it last two years?
SAGI: It depends on the usage. Even if the patient was using it’s 100 percent, we expect the life expectancy to be at least four to five years at the minimum. Certainly not as long as the traditional pacemakers. But if we can demonstrate that it is safe to take this out and put them in, it is very likely this will replace the traditional pacemakers.
This is a clinical trial for safety because it’s under medical device, it doesn’t go through three clinical trials.
SAGI: There are several phases. Obviously, the company has already completed all the safety profile, all the stages. This is almost the answer at the final stage. Stages are initial, they do animal studies and then they do feasibility studies. Then they launch it in the large clinical trial. That is the the phase we’re in right now.
END OF INTERVIEW
This information is intended for additional research purposes only. It is not to be used as a prescription or advice from Ivanhoe Broadcast News, Inc. or any medical professional interviewed. Ivanhoe Broadcast News, Inc. assumes no responsibility for the depth or accuracy of physician statements. Procedures or medicines apply to different people and medical factors; always consult your physician on medical matters.
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