Implantable Defibrillators for People at Risk of Sudden Cardiac Arrest

Intro: MemorialCare Health System, excellence in healthcare, presents Weekly Dose of Wellness. Here's your host, Deborah Howell.

Deborah Howell (Host): Hello and welcome to the show. You're listening to Weekly Dose of Wellness brought to you by MemorialCare Health System. I'm Deborah Howell, and today's guest is Dr. Thuy Le, cardiac electrophysiologist at the MemorialCare Heart and Vascular Institute at Orange Coast Memorial Medical Center. Today our topic is implantable defibrillators for people at risk of sudden cardiac arrest. Welcome, Dr. Le.

Thuy Le, MD: Thank you for having me here.

Deborah Howell (Host): It's our pleasure. We're going to talk about implantable defibrillators. What is one?

Thuy Le, MD: A defibrillator is a small electronic device that we place into a patient's chest to detect and treat life-threatening abnormal heart rhythms.

Deborah Howell (Host): Is it similar to a pacemaker?

Thuy Le, MD: Yes, it is similar to a pacemaker, but the pacemaker is only capable of treating slow heart rate. A defibrillator is capable of treating both slow as well as fast heart rate.

Deborah Howell (Host): A fast one? Maybe too fast?

Thuy Le, MD: Yes, maybe too fast.

Deborah Howell (Host): And what about flutter?

Thuy Le, MD: Flutter is usually an abnormal heart rhythm that originates from the top chambers of the heart, and we usually don't place defibrillators for those type of patients. A defibrillator is typically used to treat fast heart rate that comes from the bottom chambers of the heart, those are the more life-threatening ones.

Deborah Howell (Host): And usually they're quite large, it seems kind of amazing that you can actually have one so small and so effective.

Thuy Le, MD: Technology have progressed in such a way that the defibrillators are not that large anymore. It's maybe about two to three times the size of a pacemaker nowadays.

Deborah Howell (Host): Wow, incredible. So who would qualify for an implantable device?

Thuy Le, MD: So patients who are ideal candidates for a defibrillator are those who have already had a sudden cardiac arrest, or those who are genetically prone to sudden death, and then those who have significant cardiac damage that would also put them at risk for dying suddenly.

Deborah Howell (Host): Okay. And how have the devices changed over the years and what are the benefits of the most recent subcutaneous implantable defibrillator or SICD devices?

Thuy Le, MD: Yes, so in the past there was basically only one way of placing a defibrillator, and that's through vascular access, and when we do that we usually require fluoroscopic guidance and we place a lead or a wire through a vein and guide it under fluoroscopic guidance into the inner surface of the heart. The problem with this approach, however, is that it carries procedural complication. We talked about the risk of infection because of its systemic placement. We talked about potential nearby risk of nearby structures such as the lung, risk of cardiac perforation, as well as vessel damage. We also talked afterwards about the risk of lead dislodgement. Luckily over the past few years, there's been a newer technology that's now available where the device as well as the lead is placed completely underneath the skin, it does not have to go through any type of vascular structure, it does not have to touch the heart to protect the heart.

Deborah Howell (Host): Incredible. Have you yourself implanted these devices?

Thuy Le, MD: Yes, I was told that I'm probably the highest volume implanter right now in Orange County and we've done quite a few over the past year and have been quite successful at it.

Deborah Howell (Host): Well, congratulations, doctor. Do you see people then come into you for the SICD device to replace their old more invasive ICD device?

Thuy Le, MD: I didn't usually replace it de novo, however there has been several cases where we do go in and replace the old one with the new one. I had a young patient in his 20s who has a transvenous system placed several years ago at another facility, the lead has been recalled and was deemed to be defective, so I went in and I removed the whole system and placed a subcutaneous device for him and he's very happy. I have another young woman who prior to seeing me had a device placed several weeks in advance and had complications as a result of the device and was done with the whole system, wanted the system removed. And when I explained to her about our newer SICD, she was more than happy to have it placed and she's now back to normal activity, exercising without any limitation.

Deborah Howell (Host): Oh, that's so wonderful. You're really giving people their lives back.

Thuy Le, MD: Yes, she's very happy with it actually.

Deborah Howell (Host): Yeah, I would be too, man. That's wonderful. So what's the recovery period like after receiving the SICD device?

Thuy Le, MD: So patients are usually discharged the day after the procedure, the procedure itself will take less than an hour, and once the incision healed after about a week, there is really no limitation.

Deborah Howell (Host): Wow. Well, that's my next question. Is there any daily activities you can't do?

Thuy Le, MD: No, actually, the device does not interfere with any type of activities. Unlike the older device, there's no risk of dislodgement. So the main care after the procedure is wound healing and patients are back to regular activities of daily living.

Deborah Howell (Host): Incredible. What about, is there a scar at all or a very minimal one?

Thuy Le, MD: There is a scar and actually most of my patients prefer the location of this device because for women who are more self-conscious, it's cosmetically in a better location. So instead of having the device in an anterior location underneath their clavicle, the device is actually on the lateral aspect of their chest wall so it can be concealed easily.

Deborah Howell (Host): That's wonderful. Just the news is better and better and better for patients who need help like this.

Thuy Le, MD: Correct.

Deborah Howell (Host): So how does someone know if they may need or benefit from an SICD?

Thuy Le, MD: So in terms of patients who would need this, if you have a family history of someone dying at a young age, and what I mean by young is anyone who dies suddenly at an age of less than 40, or if you've had a heart attack, or if you have certain risk factors for heart disease, whether it's valvular disease, diabetes, or hypertension, you can go and see your cardiologist who will then measure how strong your heart is by a value called an ejection fraction. And we know that a normal healthy ejection fraction should be at least 55% or greater. And if your ejection fraction is less than 35%, then we know that you're at risk for sudden cardiac arrest.

Deborah Howell (Host): Okay, this could definitely, definitely save those lives. So what are the steps they should take to find out if they're having certain symptoms?

Thuy Le, MD: So the steps would be if you have heart failure symptoms, shortness of breath, fatigue, decreased exercise tolerance, and if you've had a history of a heart attack, the first step would to see your cardiologist, he or she will then order some sort of imaging test to measure the ejection fraction. And from there, they will send the patient as a referral to see an electrophysiologist, who is the physician that's typically the one that implants these type of devices.

Deborah Howell (Host): Do you see anything in the future that's even more exciting?

Thuy Le, MD: I do, actually. They're now coming out with leadless pacemakers, so that's very exciting for the field in general.

Deborah Howell (Host): So explain what that, explain what that might be, I mean for a person who doesn't know.

Thuy Le, MD: Yes, so most devices, pacemakers as well as defibrillators, right now the way that it's being implanted requires placement of a wire or a lead into the vascular system. And the problem with that is that we know that over 20% of patients will have lead failure by 10 years, and if the lead fail, then the problem would be going back into the heart having to remove the lead and there's procedural complications. If one is able to place a pacemaker or defibrillator without a lead, then that preserves the vasculature.

Deborah Howell (Host): Okay, wonderful. Wow, the news just keeps getting better and better. We want to thank you so, so much for being on our program today.

Thuy Le, MD: You're welcome.

Deborah Howell (Host): Where should people go if they want more information?

Thuy Le, MD: Yes, they can contact Orange Coast Memorial and West California Heart Associate, we are in Fountain Valley and we're more than happy to talk to the patients.

Deborah Howell (Host): Wonderful, Dr. Le. Is there anything else we should know?

Thuy Le, MD: No, I think that's it for now.

Deborah Howell (Host): Okay, well we want to thank you again, it's been wonderful and very enlightening and really exciting to have you on the program because there's been so many improvements and such a great quality of life for people who might not have enjoyed that previously.

Thuy Le, MD: Okay, thank you very much.

Deborah Howell (Host): To listen to the podcast or for more information, please visit memorialcare.org. That's memorialcare.org. I'm Deborah Howell. Join us again next time as we explore another Weekly Dose of Wellness brought to you by MemorialCare Health System. Have a fantastic day.