Cryoablation - What is it and Who Benefits From This Cardiac Procedure

Featuring: Evangelos "Evan" Diamantakos

Learn about this new cardiac procedure that freezes instead of burns (ablation) disease tissue that causes AFIB.


Evangelos "Evan" Diamantakos, DO, is Board Certified in Internal Medicine, Cardiology and, Cardiac Electrophysiology at Eisenhower Desert Cardiology Center in Rancho Mirage, California.

After medical school, Dr. Diamantakos completed a residency program in Internal Medicine, as well as a fellowship program in General Cardiology at McLaren Macomb Hospital in Mount Clemens, Michigan. He then completed a fellowship in Clinical Cardiac Electrophysiology at Ronald Reagan UCLA Medical Center in Los Angeles. Most recently, he was a clinical cardiac electrophysiologist at Loma Linda University Medical Center.

Dr. Diamantakos decided to pursue a career in medicine after his grandfather passed when he was in 8th grade. "My grandfather came back to the States (from Greece) after being diagnosed with cancer for his care. My parents worked full-time and I became his primary caregiver at a young age. He was my inspiration and motivation in becoming a physician," states Dr. Diamantakos. During medical school, Dr. Diamantakos had many interests, but he pursued Cardiology due to its complexity, and the willingness of patients to be proactive in their care.

"When it comes to patient care, establishing a good rapport with my patients is essential for a trusting patient-physician relationship," states Dr. Diamantakos. "Cardiac patients come to discuss vulnerable and overwhelming aspects of their care and need to depend on and have confidence in their physician. Mutual respect is very important, and I encourage my patients to be active participants in their care. In turn, my role is to provide them comfort, reassurance and quality up-to-date information on treatments that would benefit them so they can understand their options and make sound medical decisions with which they are comfortable."


Evo Terra (Host): Cryoballoon ablation, what is that? And who benefits from this cardiac procedure? Dr. Evan Diamantakos, a cardiologist specializing in cardiac electrophysiology, will tell us that and more.

Intro: You are listening to another episode of Living Well with Eisenhower Health, healthcare as it should be.

Host: This is Living Well with Eisenhower Health. I'm Evo Terra. Welcome to the show, Dr. Diamantakos.

Dr. Evan Diamantakos: Hey, thanks for having me. It's great to be here.

Host: So, heart issues run in my family, so I try and pay attention to advances in this space because I know I'm going to use them one of these days. But the term cryo with balloon and ablation is rather new to me. So, what is this?

Dr. Evan Diamantakos: Yeah. So, cryoballoon ablation can be used for multiple heart rhythms, but really the place where it found probably its most prominence to be used is in treating the arrhythmia known as atrial fibrillation. And atrial fibrillation has been around for years. It's the most common arrhythmia that us as cardiologists and as electrophysiologists treat and manage.

And when you look at the data and why we progressed so much in the field of ablation and using some modalities such as cryoballoon, is that the Center of Medicare and Medicaid services actually looked at the percent of patients that we treat who range from age groups from 60 to 80. And so if you kind of look at that span, around the ages of 60, you know, those patients that have atrial fibrillation, around 2%. It goes up to 5% as you hit 70s; late 70s, 12%. And as they get up to 85 years age or more, that's about 20% of the Medicare beneficiaries that we manage in that age group. And we know that roughly 2050, they're projecting close to 5.6 to 12.1 million patients will have AFib, which is a lot of patients across the world.

And so initially, the treatment for AFib really came about in a slow, progressive fashion, but a really nice trajectory on how medication was first used to help control the heart rate for atrial fibrillation, followed by medicines called antiarrhythm drugs, which is meant to keep patients out of AFib and in a normal rhythm. And as patients were placed on medicines, you can imagine they all have side effects or can have side effects from different types of medicines. And so, ablation came to the forefront as I mentioned, began treating other arrhythmias. And so, the first electrical studies to manage or study these rhythms really came around the late '60s, early '70s. And then roughly around 1980s, early '80s and mid-'80s, is when they started using ablation to treat what we call supraventricular or tachycardic rhythms and even fatal rhythms called ventricular rhythms from the bottom chamber of the heart.

And so, the first actual atrial fibrillation ablation occurred in 1994. And from 1994 until now, we have seen progression in how we use ablation. So, how we use that equipment to cauterize or, in the setting of cryoballoon, freeze tissue in the heart. And we found what was the most appropriate way of managing that for patients. So, many studies out there looking at different ways to approach the atrial chamber where AFib happens.

And it wasn't until 2013 that one of the initial companies that came out with the cryoballoon said, "Hey, we have this device. It's a balloon that can approach the veins in the atrial chamber where AFib happens." And they started looking at studies and said, "Hey, if we freeze tissue instead of heating it, can we get the same benefit? Can we help our patients stay free from atrial fibrillation?" And so, the first studies came out in 2013. And then over the course of the next subsequent years, became FDA approved for patients who primarily have what's called paroxysmal atrial fibrillation. That is atrial fibrillation that by definition lasts under seven days, or they had undergone an electrical or chemical conversion to get them out of AFib into a normal rhythm. And so, those patients were the ones that were first studied because the early studies that used heating or what we call radiofrequency ablation looked at paroxysmal patients. So, the companies really wanted to make a good comparison and say, "Hey, we have a lot of data on patients who have AFib who had a heating modality to treat their rhythm. Now, we're going to compare that with the freezing." And the data is great, and the data has remained consistent since 2013 forward, such that even some of the more recent trials are using cryoballoon ablation as the first treatment option for paroxysmal patients, because long term, as I mentioned earlier, patients just don't tolerate side effects of drugs. And so, ablation seems to be a better way of keeping them in rhythm longer, that's most important. And they don't have to take a daily pill to help keep them in rhythm or help control the heart rate.

So, what's cool about the balloon, it is actually spherical. So, it's a circumferential balloon that has a preset size that will actually plug or what we say occlude the opening of the pulmonary vein. So, those are vein structures that drain into the atrial chamber, and we know that that tissue that sits near those openings is the most irritable when it comes to AFib. So, we know we have to target those in what we call a substrate or structural-based approach. So when the balloon actually approaches those vein openings, we can identify whether or not we have a good occlusion or the balloon is nicely pressing up against the opening of that vein, either with the use of contrast or something called pressure wave monitoring. So, it's a cool tool that allows us to see a change in pressure once we've occluded something. So, for example, if you think of a clogged toilet, obviously there's built up pressure, right? And so, that obviously backflows. So, we have a pressure system that allows us to sense when there's backflow. That means we've had a good occlusion of that vein.

And then, going forward, what's nice about the actual balloon itself and the catheters that come with it, is it gives us real-time feedback. So, we actually can see the AFib signal or what we call the pulmonary vein signal in real time. So as we're freezing the tissue, we can slowly, slowly watch that signal go away. And that is nice for us to say, "Hey, this looks like a good freeze. We have good contact. We provided a good application of this balloon to this vein." And there's idiosyncrasies that we have to be aware of, how long it took for that signal to go away, how cold did the balloon get during the application process.

So, there's some things we look on the back end to make sure that this is a good application, but the balloon has changed our way of managing AFib to be more efficient, number one. Number two, offer the same great results we can with even heating for applications for AFib. And procedure times are actually a lot shorter. So roughly, the procedure times are estimated somewhere between 60 and 90 minutes, which is very common. And with my patients, that's pretty much where I've been running at times. From start to finish, it can be roughly two hours. But the patients that do get these ablations done do have good long-term results.

Host: Well, that's good news. I haven't had this done, but my mom has AFib and my mom has had the ablation, which I assume is a heated version because she talks about burning scar tissues, you know, her terminology for it. So, it sounds like she might be a good candidate for something like this possibly because she's been through it before. Would you agree with that statement? Basically having no idea who this patient is whatsoever, other than knowing she's in her late '70s and she's had this procedure done a couple of times.

Dr. Evan Diamantakos: it's a great point that you bring it up because a lot of my patients that I see are patients who've had AFib ablations done before and, as you mentioned, from a heating perspective. And so, can a patient who has had a heating ,procedure done first get a cryoballoon ablation done for their second ablation? And actually, they recently published a study on that that showed sometimes patients benefit better when you change the modality. So if they had a freezing balloon ablation done first, you should try heating the second time around and vice versa. And so, the best way to really make that decision in my opinion is we always use a catheter that helps us understand the electricity that exists in that chamber, whether it's a patient who's had an ablation before, so we can see what's healthy and now what has become scar tissue or what we call a virgin atrium, a chamber that has not been touched by an ablation. And so, we can see in the natural state of that chamber what is healthy and what is not.

And oftentimes that the initial premapping that we do really helps guide us to say, "Hey, we think this patient will probably benefit from a balloon ablation," or "Gosh, it looks like there might be more work that needs to be done." And so, using a heating catheter to get to more areas of the heart where you're oftentimes limited with the balloon to really just target the vein structures of that chamber, we have to understand what's going to be the best option for our patient. And premapping really does help guide us to choose one over the other.

Host: You mentioned oftentimes a shorter time in the operating theater at this particular procedure. But are there other benefits to having cryoballoon ablation as opposed to the more standard heating element ablation?

Dr. Evan Diamantakos: Yeah. Great question. So, definitely if it's a shorter procedure time, then bedrest afterwards becomes a lot shorter. Getting patients home same-day discharge is always a good quality of life indicator that we try to strive for because happy patients with good results will lead to long-term good outcomes and they'll be satisfied with their results.

The balloon does have similar complications we have to watch out for. So, I always think of it as know your neighbors, what other structures are around the atrial chamber, right? And so, there's the esophagus, which is the food pipe for swallowing food. There's a nerve called the phrenic nerve, which helps the diaphragm move up and down. There's the aorta that's around the atrial chamber, and lung tissue. So, oftentimes where we can see with the balloon. And it's of no detriment to the patient as they may inherently cough during the procedure. So when they're under anesthesia, they what we call bucking the vent, where they'll actually give this reflex cough. So, we have to understand, "Okay, this is a little too cold for this area." So, there's there that to look out for.

When we assess the nerve that helps the diaphragm move up and down, the phrenic nerve, we actually can do it multiple ways. I think the safest way and a way that allows all the staff to be involved is we actually place a baby monitor or a baby belt across the belly and we then place a catheter where we believe structurally the nerve is in the heart, and we begin pacing that nerve. So if you pace it correctly, you should start to hear a swooshing sound because you've actually stimulated the nerve that makes the diaphragm move and then makes the baby monitor start to make sound. So, we understand the pitch of that sound and the intensity of that sound. And as we freeze near that vein where that nerve runs, if we start to hear a diminished phrenic nerve, then that means, "Okay, we are now starting to penetrate on our neighbor," and that means we either have to come off the balloon or minimize the application in that spot or what I call kind of patchwork. Come to it once, go to a different spot, come back to it again, give the nerve some time to recover.

So, a phrenic nerve injury is something we do stay on top of. It's reported roughly around 3%. The earlier studies headed higher around 11-14%, so really, really high. And so if you were to tell me one versus the other, does the cryoballoon carry just a slightly higher risk of phrenic nerve injury? It can. After a year, if somebody did have an injury to their nerve, only about 0.9% did not recover of the group that they looked at. So, they will recover over time, it just takes a little bit longer.

With heating, there's always concern, "Gosh, are you going to heat through the muscle of the heart and cause a problem?" And so with freezing balloon, you're not really worried about that. That is true. And so from a overall safety standpoint with efficiency, I think the balloon wins out over the heating application.

Host: Right. Right. Any additional side effects with this procedure to talk about, or are they just the same as ablation overall?

Dr. Evan Diamantakos: Yeah. They're both the same for ablations. There really is no other differences other than the ones that I just mentioned that we're a little bit more hyperaware of, particularly the phrenic nerve injury. So, the complication risk actually, they just came out with it in the recent Medicare statement that I think it came out probably two or three months ago. Ablation risk used to be as high as 5%, and that's major adverse events, bleeding, bruising, damage to the heart tissue, death, heart attack, stroke need for open heart surgery if there was a complication. It now has dropped to about 2.4%. And some studies will say even as high as maybe 3% or 3.5%. So, the fact that electrophysiologists have gained more experience, have become more comfortable with the tools that are available and companies are now producing ablation techniques that make things safer. I do anticipate that that risk will either stay where it's at or even become less for patients over time.

Host: That's very good news. Thinking back to my mom who I know has had the procedure or a procedure, not cryoballoon we're speaking of today. I know she's had two different ablation procedures with balloon. Is the hope there that this was more long-lasting? That's the real question, is this eventually going to be the procedure that we do, and maybe once and maybe you're all done?

Dr. Evan Diamantakos: Great question. And oftentimes we don't have a crystal ball to always know the future, but the recurrence rates really rely on the type of AFib patients have. So, paroxysmal patients, whether it's freezing, heating or even we have laser balloons that are out there as well for vein ablation, the success in the first year is roughly around 80%. And if you look past that year timeframe, usually the success will drop an additional 10% or so.

And so, what we do know is that when you're on medication, your chance of recurrence is higher than with an ablation. That's what the recent data has suggested. Patients who are persistent, that means they're in AFib for more than seven days, but just shy of a year, their success from an ablation runs around 60-70% because their tissue has changed over that time being in AFib. I think of AFib as a rhythm that leaves cookie crumbs. And if it leaves enough to know how to get back home, it will then go ahead and reoccur frequently and start to change the confirmation of the chamber that can make it instead of being a nice sphere, it starts to become globular or lumpy and even create more scar. And on top of that, unfortunately, we don't have the Fountain of Youth solution yet. And so as we age, the inside of the heart gets older. So, almost insult to injury from an AFib standpoint.

And for patients who stay in AFib over a year, we call them long-standing persistent. Their success rate for an ablation usually drops from 50% or lower. So, it's the persistent and long-standing persistent patients that oftentimes need more than one ablation. The paroxysmal patients oftentimes can get away with just one ablation, and that can either be cryoballoon, that can be freezing.

But what's nice about cryoballoon, I think what separates it from heating or the radiofrequency ablation is that you will have less recurrence of atypical flutter rhythms with cryoballoon ablation, because you have a balloon that covers a larger surface area that does not leave gaps behind. And when you're using a heating catheter, it's like spot welding. So, you have to make sure that when you are cauterizing that tissue, you are allowing for a nice overlap or a chain link of what we call lesions or ablation applications that will stand the test of time and hold that tissue and render it electrically inactive. And so with a balloon, you just have to make sure you have good contact. You're getting good feedback saying this is a quality application. And oftentimes if you do have to go back for a patient who does have a cryoballoon, a previous cryoballoon ablation, it's usually touchup. Just kind of like repainting a painting, just go into a spot where you need to touch it up a little bit with a heating catheter and that oftentimes is all it takes.

Host: Well, it sounds like this is quite an improvement over a procedure that hasn't existed for much longer than 25 years, but still it's great to see medicine moving at the pace that it is. Is there anything else I didn't ask you would like me to ask you?

Dr. Evan Diamantakos: I think one thing I didn't answer on that last question is where does this stand the test of time as far as other ablation modalities that are coming down the pipeline. And so with medicine and in any field, we always want to do better, we always want to offer better, and we want good results with safety in mind, right, first and foremost for our patients.

And so, there is new technology coming out hopefully within the next five years that may actually be a replacement for balloon and/or thermal or heating energy application, or it may just be another tool in our armamentarium that we have where there are some patients that do better with cryoballoon, there are some patients that do better with heating and some of these other newer technologies that are coming down the pipeline.

So, I think what's nice about medicine is it is a recipe. It is not cookie cutter whatsoever. Every patient does require a thought process to know what's going to work best. And if one modality was chosen that didn't give the result we were hoping for, then try something different, offer them something different. And I think that's great here at our facility at Eisenhower, that we have the capability to have two modalities that we can offer our patients. Because if one didn't work, who's to say that the other one won't help fill the gap and fix what wasn't able to be taken care of on the first go round?

Host: Yeah, that sounded great. And I give you 20 years to get that Fountain of Youth figured out, so you can just give me a young heart. How about that?

Dr. Evan Diamantakos: I wish.

Host: Dr. Diamantakos, thank you so much for spending time with us today.

Dr. Evan Diamantakos: Appreciate it. Thank you so much.

Host: Once again, that was Dr. Evan Diamantakos, a cardiologist specializing in cardiac electrophysiology. For more information, you can go to That's And if you found this episode helpful, please share it on your social channels. You can also check out our full podcast library for other topics of interest to you. I'm Evo Terra. Thanks for listening to Living Well with Eisenhower Health, healthcare as it should be.