What Really Happens During A Catheter Ablation For Atrial Fibrillation?
If you are considering a catheter ablation to treat atrial fibrillation, here are some tips I can give you about what really happens during an ablation procedure. I’ll walk your through a typical consultation, the preparation, the procedure itself, and the expected recovery.
What to Expect During a Consultation with an Electrophysiologist:
A first step in deciding about a catheter ablation is to assess if you are a good candidate for the procedure itself. In general, patients in earlier stages of atrial fibrillation, called paroxysmal atrial fibrillation, have a better success rate than patient with advanced stages of atrial fibrillation, also called persistent atrial fibrillation. I have discussed several times in the past on how stages of atrial fibrillation affect treatment options. Another topic to discuss with your doctor is your additional medical conditions including your age, additional heart conditions such as congestive heart failure and coronary artery disease, as well as significant lung conditions such as COPD. Your doctor will go over the typical procedure details and what to expect before and after the procedure. Any detailed discussion regarding a catheter ablation should also include a discussion of the risks of the procedure, which may include bleeding, and a perforation of the heart tissue. However, for many people the benefits of the procedure outweigh the risks, and the overall risks and recovery time for catheter ablation are better then a surgical ablation. A catheter ablation is not a 100% cure for atrial fibrillation, but it works much better then any medication to significantly improve symptoms of atrial fibrillation.
Preparation For The Procedure:
After you have agreed with your doctor to proceed with a catheter ablation, what are the next preoperative steps?
The next step is to make sure you are medically optimized as best as possible prior to the procedure. This may include steps such as adjusting blood pressure medications or treating your congestive heart failure, for example. Preoperative testing would likely include blood work, which would test item such as your blood counts and kidney function. Likely there is a pre-procedure chest x-ray that is used a baseline and can be compared post procedure to another x-ray if needed. You doctor may also get a procedure cardiac CT or MRI, these may be used to better identify your anatomy of your heart, such as the size of the left atrium, evaluate for a presence or absence of a blood clot in your heart prior to the procedure, or also used to assess for scar tissue in your atrium. Alternatively, your doctor may schedule a trans-esophageal echo (also called a TEE) either the morning of the procedure or the day prior to the procedure. This a very detailed ultrasound of your heart, usually used evaluate for a presence or absence of a blood clot in your heart prior to the procedure. All of this information can be useful to your doctor to develop a strategy for your procedure.
Day Of The Procedure:
In the morning of the procedure you will likely be prepared in a pre-procedure area. Typically an IV is inserted to give medications during the procedure. You will likely be shaved along your groin (this is where your doctor enters your veins typically for the procedure), also your chest may be shaved if needed as multiple cardiac electrodes are placed on the chest during the procedure to monitor your heartbeat very closely. During the pre-procedure area you will also likely meet your anesthesiologist. Most ablations procedures are done with anesthesia, as the process of burning or freezing inside of your heart can be painful for someone who is awake. At my hospital I also have the anesthesiologist insert a small arterial catheter into an artery in your wrist, which is used to closely monitor your blood pressure during the procedure.
Pulmonary Vein Isolation:
Now what actually happens when the patient goes to sleep? In the procedure you will be lying on an X-ray table. The procedure begins by your doctor entering into the veins in your groin with a needle puncture, also called the femoral veins. Typically multiple punctures are needed as there are multiple catheters used during the procedure. Your doctor will then advance the catheters into your heart. In order to perform an ablation for atrial fibrillation, your doctor will need to get into the left atrium, which is the left upper chamber of the heart; this is where most people’s atrial fibrillation comes from. In order to get there, your doctor will typically need to do what is called a trans-septal puncture. Basically your doctor will create a very small hole to cross from the right upper chamber to left upper chamber of your heart. This small hole typically heals on its own several weeks after the procedure. In sounds dramatic to describe that your doctor will intentionally create a small hole in your heart, but with proper safety equipment, this is a very routine part of the procedure that only takes a few minutes.
Once your doctor has all the necessary equipment in place, then he or she will start the ablation process. During an ablation for atrial fibrillation the main targets are the pulmonary veins, located in the left atrium. Typically patients have 4 pulmonary veins that drain blood from your lungs back to your heart. These pulmonary veins have extensions of nerves and heart tissue that can trigger episodes of atrial fibrillation. This is a common source for most patient’s atrial fibrillation. As a result, the main goal during an ablation the primary goal is to make strategic scar inside your heart to block these triggers that can lead to episodes of atrial fibrillation. This scar does not affect the blood flow from the lungs back to your heart but blocks those trigger areas to reduce your atrial fibrillation. You doctor will then ablate the tissue near the pulmonary veins using either radiofrequency (burning methods) or cryotherapy (freezing methods). The goal is to have a thorough ablation performed of all 4 pulmonary veins during the procedure. This is a process that can typically take around 3 hours to do. After completion of the pulmonary vein ablation, your doctor may do additional testing to see if you can still be induced into atrial fibrillation or another arrhythmia. What I tell patients is that this is the part that is customized per patient. Atrial fibrillation affects hearts in different ways, while inside of your heart your doctor can have a detailed assessment of how much atrial fibrillation has affected your heart, most commonly this is seen through the amount of scar tissue noted in your left atrium or by identifying additional triggers for atrial fibrillation which can be identified by giving a stimulant type medication such as Isuprel.
After The Procedure:
After the procedure you will be typically transferred to a recovery area. Here your heart beat and blood pressure will be monitored closely after the procedure. I typically order a chest x-ray after the procedure to make a comparison to the pre-procedure chest x-ray. I do this to check for signs of fluid accumulation during the procedure in your lungs, which can later cause shortness of breath. Its not uncommon to have several liters of intravenous fluid given during a catheter ablation through both your anesthesiologist as well as with the ablation catheter itself. You will usually have to rest in bed for several hours, typically about 4 hours to minimize risk of bleeding at your groin puncture site. Depending on your doctor’s preference, some patients may be able to go home the same day, while some may need to stay overnight in the hospital to recover.
What to Expect After The Procedure:
After the procedure you can except to have some groin bruising and soreness. However you should never have severe pain in your groin or bleeding, if you have those please alert your doctor. Chest discomfort can also be expected due to the ablation process. Due to the inflammation from the procedure, it is typically a very positional discomfort, for example you may notice it more lying down versus sitting up. Again, it should not be severe pain, if you have severe pain please alert your doctor.
But what about your atrial fibrillation? Do you get immediate relief after the procedure? Can you immediately stop medications after the ablation? Not so fast unfortunately. I usually explain to patients that during an ablation you are making strategic scar inside of your heart. Just like when you cut your skin, it does not heal or form a scar right away; there is a period of healing and waiting for the inflammation from the ablation to subside. Because of this I typically wait for at least one month before I start to decrease medications for atrial fibrillation.
The best benefits from an ablation procedure can take up to 3 months after the procedure itself. This is what is commonly referred to as the “blanking period.” This is because it is well known that it can take a while for the ablation lesions to fully mature. During this period, recurrences of atrial fibrillation can happen. Although it is, of course, ideal to not have any recurrences of atrial fibrillation, having recurrences during the first few months does not necessarily mean that the ablation didn’t work. I have had several patients that have had recurrences of their atrial fibrillation in the first few months after an ablation procedure but then have very successful outcomes as time goes by and the lesions fully mature. Even in clinical trials for new techniques for ablation procedures, recurrences in the first three months do not count towards counting a procedure as a failure or success. This is the very reason why I do not decrease medications right away after an ablation and typically wait at least a month after the procedure to decrease medications.
A catheter ablation can be an excellent option for many patients with atrial fibrillation, especially in situations where patients continue with significant symptoms despite medications. But it is not perfect, recurrences can happen, and there are many patients that need more then one ablation to get good control over atrial fibrillation. But always discuss with your doctor the risks and benefits of a catheter ablation, and to see if it is the right option for you.