Cryoballoon Ablation for Atrial Fibrillation — Video of Jay O. Franklin, MD, FACC, FHRS
December 19, 2013
In this video from the Get in Rhythm. Stay in Rhythm.™ Atrial Fibrillation Patient Conference, Dr. Jay O. Franklin talked about cryoballoon ablation and compared it to radiofrequency catheter ablation.
Video watching time is approximately 15 minutes.
About Jay O. Franklin, MD, FACC, FHRS
Dr. Jay O. Franklin is a clinical cardiac electrophysiologist practicing with Cardiology Consultants of Texas in Dallas at Baylor since 1988. Dr. Franklin’s primary interests include catheter ablation of arrhythmias and device management of heart rhythm abnormalities.
Dr. Franklin is Board Certified in Internal Medicine, Cardiovascular Disease and Cardiac Electrophysiology. He is currently conducting several clinical research trials and has published a number of articles that have appeared in widely respected journals. He is also involved in important research projects to advance medical knowledge of cardiology.
Dr. Franklin was named a Super Doctor for 2010 by Texas Monthly Magazine, and was recently named by Patients’ Choice Award 2012 as “Best of the Best”, a distinction he has received for five years in a row.
Dr. Franklin received his medical degree from Texas A&M University College of Medicine, College Station and Temple where he also served his internship in Internal Medicine. He fulfilled his residency and chief residency in Internal Medicine at the University of Louisville in Kentucky. He then completed a fellowship in Cardiovascular Medicine at the University of Missouri in Columbia and a fellowship in Cardiac Electrophysiology at the Cardiovascular Research Institute, University of California in San Francisco.
Dr. Franklin is a Fellow of the American College of Cardiology and the North American Society of Pacing and Electrophysiology. He is an active member of the American Heart Association, American Medical Association, Dallas County Medical Society, and Texas Medical Association.
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Mellanie: Our next presenter is Dr. Jay Olen Franklin. Dr. Franklin is a clinical cardiac electrophysiologist practicing since 1988 with Cardiology Consultants of Texas and Baylor Heart and Vascular Hospital in Dallas. He has won a number of awards including Texas Super Doctor from Texas Monthly Magazine. He is a researcher with a special interest in afib catheter ablation and is widely published.
Dr. Jay O. Franklin: I also want to give my thanks to Mellanie for asking us to be involved, and to Rob Kowal, who helped in organizing this. Also, to Dr. Rizvi, whose talk is going to help me because he explained some of the more difficult concepts for me as he talked about catheter ablation.
I’m going to talk about cryoballoon catheter ablation. It is different from radiofrequency catheter ablation, purely based on the energy source that we use. [1:12] We all cut our teeth using radiofrequency catheters, and we still use radiofrequency catheters for most of the catheter ablation treatment that we utilize for patients with rhythm abnormalities. It’s unique with the cryoballoon in that we can freeze vessels and create the same sort of scar that we want to create with the radio-frequency catheter, and that’s what we’ll talk about.
When we look at afib, I’m going to do the same sort of thing Dr. Rizvi did, so we may beat you up with this along the way, [1:45] but our goal is to restore and maintain sinus rhythm, both to hopefully reduce the risk of blood clots and stroke, and more importantly, to alleviate the disabling symptoms of rapid and inefficient heartbeats that occur with afib. As you’ve heard, the options include heart rhythm drugs, surgery, including the maze procedure or variations of that, and the two catheter ablation treatments that we utilize to correct rhythms with invasive procedures, both “ablate and pace”, or AV node modification, or pulmonary vein isolation, techniques where we’ll use either radiofrequency ablation, which you’ve heard about, or cryoablation, which I’ll explain further. Pacemakers will help prevent slow heart rates, but don’t prevent atrial fibrillation. In the old days, we mistakenly thought that a pacemaker would keep patients from having afib. Often times, they’ll facilitate our treatment with other drug therapy. Then cardioversion, which restores rhythm to normal but requires some other form of treatment to help maintain treatment because cardioversion only restores the rhythm, it doesn’t do anything to keep it.
[2:56] The guidelines that we all try to follow in regards to atrial fibrillation come from a group of committees from the American College of Cardiology Foundation, the American Heart Association, and the Heart Rhythm Society. The Heart Rhythm Society is what electrophysiologists around the world belong to. It started out as a US organization, but has included people from all around the world; it’s the group of electrophysiologists, and provides us with our greatest source of information as we take care of patients, especially in regards to what is the standard of care, not only locally, but worldwide, in patient care.
[3:43] Within the most recent set of guidelines for afib, the guidelines suggest that patients that continue to have symptomatic atrial fibrillation should be considered for afib ablation, or pulmonary vein isolation. If patients are continuing to be symptomatic despite drug therapy, then ablative therapy is reasonable. [4:03] Especially in young individuals that are very symptomatic, ablation may be preferred over years of drug therapy. If you have any other rhythm abnormality besides afib, you’ll find most electrophysiologists considering catheter ablation as the first treatment option, often times, rather than committing you to having to be treated with drug therapy. The current standard now requires, for the most part, that we treat patients with medications first and save ablation until later, except in selected cases.
[4:35] You saw this demonstration about radiofrequency catheter ablation. As you’ll see, the little yellow dots that are going around the lasso-shaped catheter in the vein indicate the kind of the tedious process that is required to do a radiofrequency ablation. The beating heart makes it difficult to keep our position. How much pressure we put around that pulmonary vein varies from location within the left atrium; both the different pulmonary veins require different maneuvers to get to that area. It’s technically challenging and it’s slow to perform. Doctors vary in their abilities and success rates with this technique. So, it makes it a little difficult to transfer the results from one doctor to another doctor. It’s very dependent on how skilled your ablation physician is as to how good a result you may or may not get with radiofrequency catheter ablation; it requires overlapping scars be achieved.
[5:39] The pulmonary vein, as Dr. Rizvi pointed out, clearly is the key problem. We now recognize that ablation strategies which target the pulmonary veins are the cornerstone for atrial fibrillation ablation, and the majority of afib ablation procedures target those veins. [5:58] With the advent of the cryoballoon technique, it has been approved as one of the two options for catheter ablative therapy within the most recent Heart Rhythm Society consensus statement.
[6:13] This is what it looks like to give you an idea. This is a cartoon that shows the balloon in a pulmonary vein, and it shows that, as it freezes, it creates that blue scar. The beauty, for me, of coming to this kind of meeting is I get to hear how other physicians describe this to patients. I talk to patients about a moat around the pulmonary vein that scars a moat around the vein that prevents these pulmonary vein potentials from getting into the atrium and causing afib. I like Dr. Rizvi’s comments about a fence that we erect that blocks conduction into the atrium. In essence, it’s a scar that’s created whether you use heating energy with the radiofrequency catheter or freezing energy with the balloon. We get a scar by freezing that tissue.
[7:05] It requires a big console with some fancy equipment; the catheter you see is attached to that console. It uses liquid nitrous oxide that’s delivered from the console into the balloon that’s inside the patients left atrium in the heart. Inside the balloon, it vaporizes and absorbs the heat, and then the vapor is returned back to the console through the tubing that’s attached to the console. The console allows us to move that nitrous oxide safely in and out of the patient’s heart via the catheter so that we can freeze to create the scar that we need.
[7:44] This, again, shows the control mechanism of the balloon, and it’s a fairly complicated piece of technology. They come in a couple of sizes; it’s not like Wal-Mart—it’s not one-size-fits-all. We have two choices to use, and we’ve seen improvements in the balloon. We started out with the balloon that was not very flexible, and the latest rendition of it is a much more flexible balloon that allows us to do a better job of one-size-fits-all.
[8:13] The latest addition to this is the use of the Achieve™ catheter. We use these lasso-shaped catheters, as you see here, the circular catheter, for mapping those pulmonary veins. We’ll put those lasso-shaped catheters in and out of veins so we can see the electrical activity both to know that it’s there before we ablate and also confirm that we’ve gotten rid of the potentials to confirm that we’ve been successful.
[8:43] Basically, we have to work inside the left atrium. That requires we make a puncture from one chamber to the other. In the first image, you see that we’ve accessed the targeted vein, that we had the lasso catheter in that vein. We inflate the balloon and position it in the opening of the pulmonary vein, then occlude, and freeze and ablate the area, and then we’ll re-look to see evidence that we’ve gotten rid of the potentials in the vein.
[9:12] This shows the electrical signals that we see moving away, and they’re difficult, but this is what a pulmonary vein potential looks like here. Here’s where freezing this potential moves further out time wise, and then it moves away and is completely gone so that this electrical signal here now becomes flattened. This is what it looks like with the balloon inflated in the pulmonary vein with the lasso catheter in the vein.
[9:43] This is a video that shows exactly the same thing, but I think is a very nice way to demonstrate to you what takes place. Here’s the catheter going up into the left atrium doing the transseptal catheterization. You see the lighting storm there—that is the pulmonary veins firing. This is the little lasso catheter that we position into the opening of the vein to record those electrical signals. Then, the balloon is moved over that wire out into the body of the atrium. You can see the lightning storm there again—we want to get rid of that electrical pattern going on there. The balloon is placed into the opening of the vessel; you’re looking from the opposite side. Here the balloon is positioned inside the vein. We push pretty firmly against there to get a good seal, and we put dye into the vein to make sure that we have completely occluded the vessel temporarily so that the dye shows us that we have an occlusion, which means that we will get a nice circumferential fence, or scar. And then here demonstrates the—sorry, I’m not going to make you see the whole video again. Basically, I was going to show the electrical signal going away, but all it was demonstrating was the balloon in the vessel freezing at the time.
[11:15] The overall conclusions with what we’re doing with our current cryoballoon—which is made by Medtronic, and we’ve had both European trials and a trial called StopAF—showed that cryotherapy effectively treats atrial fib that fails drug therapy. It’s a safe procedure. It’s a straightforward and very efficient procedure. The treatment success improves with physician training and experience, and it results in shorter procedure times compared to conventional radiofrequency ablation procedures.
[11:46] Why use the cryoballoon? It’s faster, a little less risky—it’s as good as, or better than, radiofrequency catheter ablation. It’s easier for the patient and the physician. In most cases, not all, it can be done with one transseptal puncture, meaning we only have to puncture once across the inter-atrial septum, the divider between the two upper chambers. It doesn’t require fancy three-dimensional mapping, which is fairly expensive.
[12:15] What to expect before you get ablated? Blood thinner. Heart rhythm medications. What Dr. Rizvi indicted about stopping drug therapy or changing blood thinners depends on the individual physician. Most of us now are comfortable with doing your procedure completely anticoagulated on your blood thinner, depending on what that drug is. Some of us do, and some of us don’t, stop your heart rhythm medicines ahead of time—that will vary with you doctor, as he pointed out. I do agree that a transesophageal echo is important for most patients prior to the procedure, and we will usually have done some basic heart testing ahead of time.
[12:56] What do you expect during and after? It’s going to be a several hour procedure, typically a little shorter than radiofrequency catheter ablation in my hands. We also use general anesthesia. It requires an overnight stay, as was indicated. Most every patient goes back on blood thinner for typically two months, or perhaps as long as three months, depending on your need for blood thinner overall. Occasionally, patients will have some atrial fibrillation for the first month to three months, and I tell patients that’s not a deal-breaker; it doesn’t mean you had a successful procedure. The scars that we create, however we create them, take a little while for the healing process to occur to prevent a recurrence. Basic numbers are about a 20% chance of a second procedure, although we’re finding in our most recent data our numbers appear to be much lower than that; and our EP trainee, who’s learning to do what we do, has sent an abstract that shows a much lower number of redo rates in our cryoballoon patients. But, about a 70% chance of long term prevention of afib with this as a single procedure, much as it was explained.
[14:04] Complications are the same, in general, although the phrenic nerve, the nerve that controls the diaphragm, affects your breathing; that phrenic nerve has a little greater tendency to be affected. Pulmonary vein stenosis, or narrowing, can occur. Esophageal injuries are less common.
[14:26] Patients are up and ambulatory, back on their blood thinners, and go home the following day, returning to work in a day to seven days post procedure.
[14:35] Why not have a cryoballoon? If you have persistent afib, and you know you’re going to need a lot of radiofrequency energy delivery then we’re not necessarily going to use the cryoballoon. Patients that need a lot more work that we know ahead of time, we’ll use radiofrequency energy as our primary source because it’s less expensive. If you’ve had a previous cryoballoon ablation, in general, it doesn’t make sense to do a second one.