**EP40: What Is Electrophysiological Ablation Of Atrial Fibrillation?**
**Dr. Warwick:** Welcome to Dr. Warwick's podcast channel. Warwick is a practicing cardiologist and author with a passion for improving care by helping patients understand their heart health through education. Warwick believes educated patients get the best health care. Discover and understand the latest approaches and technology in heart care and how this might apply to you or someone you love.
Hi, my name is Dr. Warwick Bishop, and I'd like to welcome you to my consulting room. Today, I'd like to talk a little bit about EP, or electrophysiological ablation of atrial fibrillation. Well, electrophysiological simply means pertaining to the electrical function of the heart. So, we have specialists within cardiology who are called electrophysiologists. They have subspecialized within cardiology, dealing with an understanding, treatment, and management of conditions related to the electrics of the heart or the electrical system.
Ablation simply means removal. So, EP, electrophysiological, removal of atrial fibrillation. Well, it's not strictly removal, but I will explain that in a bit more detail.
Well, why would we do something like an electrophysiological ablation for atrial fibrillation? Well, we'll generally get to that stage if, by simple lifestyle modification and intervention, together with a drug regime, we're unable to effectively control someone who is symptomatic from atrial fibrillation.
Why does electrophysiological ablation work? There are cells that line the left atrium which are called muscle cells or atrial myocytes. It would seem that some of these myocytes actually extend into the pulmonary veins. So, these muscle cells start to have small extensions into the veins that are returning oxygenated blood from the lungs to the heart.
Now, the trouble is that these cells were never really meant to be within the veins. And as they are in that area, in that location, their function is somewhat deranged, and their communication with each other is somewhat deranged as well. This means that they can fire off intermittently and create, if you like, disturbance within the electrical milieu of the left atrium.
So, an electrophysiological ablation of atrial fibrillation means that we separate those cells within the vein from the cells within the left atrium. So, if you imagine one of the pulmonary veins coming into the left atrium, we ring bark it, literally separating the cells within the pulmonary vein that may be exciting the cells within the left atrium and causing erratic and chaotic contraction or precipitating atrial fibrillation. This ring barking is called pulmonary vein isolation.
Well, how do we do it? There are more and more clever techniques, but essentially it's a catheter technique, which means it's on the long tube, and using different modalities, either radiofrequency, freezing, or burning, the tissue in a ring-like formation is damaged, killed, burnt, or scarred so that it no longer functions. Those cells that are within the pulmonary vein, which are literally misbehaving, are separated from the cells that are in the left atrium, which are hopefully moving together in an orchestrated way.
Well, how do we get to do this? The left atrium is right up here, and it's quite deep in the body. Well, the procedure is generally undertaken by gaining access to the venous system in the leg. The electrophysiologist will pass a special catheter up into the right side of the heart. That catheter will then cross between the atria through the intra-atrial septum from the right side to the left side. And then, by rather impressive manipulation, the catheter is then placed into all four of the pulmonary veins.
As it's placed into each of those pulmonary veins, a circumferential derangement of the cells, a burning or freezing or ablation is performed. The electrophysiologist has some guidance because the patients have had a CT scan of their left atrium, which gives a shape or a visual of exactly what the shape and the arrangement of those pulmonary veins is. And so, there's a bit of guidance to help the electrophysiologist know exactly where they are with a set of CT images set up to guide the procedure.
The procedure can take several hours, as you can imagine. It sounds pretty complicated, and it is pretty complicated. Generally, the patient will be on an anticoagulant during that time because, as you imagine, if we're deranging those cells, we are creating rough spots, and those rough spots could be a focus for formation of clot. And so, being on an anticoagulant becomes important in that situation. Often, the patients can go home the next day.
Well, how effective is it? In my own experience, I probably see 70% to 80% of patients come back with a very successful result, and generally in the longer term, those patients will do well, with occasionally maybe five to ten percent of people requiring a second visit. Who goes for a second visit, at what time frame, and in what circumstance really all comes down to the individual, their specific situation, and the experience of the doctor who's dealing with them in dealing with that person's symptoms, but also with the risk of the condition.
This is a tremendous technology. We do tend to keep it for patients who are younger. We do tend to keep it specifically for patients who are symptomatic from atrial fibrillation because it helps us control the rhythm. And we do also try and make sure that we consider this intervention, EP ablation of atrial fibrillation, in hearts that are relatively structurally normal. If the heart is structurally significantly abnormal, then the chance of success is markedly reduced.
Well, I hope that tells you a little bit about EP ablation and atrial fibrillation. I thank you for joining me, and as always, I wish you good health. Goodbye.
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