A Patient Guide to Atrial Fibrillation and Catheter Ablation Al-Sabah Arrhythmia Institute 1111 Amsterdam Avenue New York, NY 10025 Phone: 212-523-2400 Fax: 212-523-2571 www.stlukescardiology.org Printed with permission from the Atrial Fibrillation and Complex Arrhythmia Serviced California Pacific Medical Center San Francisco, California
Atrial fibrillation (AF) also known How does the heart normally work as A-fib is the most common heart rhythm abnormality (arrhythmia) in the United States affecting approximately 2.5 million people. AF can occur at any age but is more common as we get older. To better understand A-fib, it is useful to understand the normal electrical and mechanical functions of the heart The heart has four chambers; two are on the right side and two are on the left Some people with atrial fibrillation have few or no side. The right side of the heart receives symptoms while others have symptoms that can be blood from the body into the right atrium debilitating. Regardless of the presence of symptoms, (upper chamber). The right atrium then without proper treatment, AF can cause a weakening contracts and pushes the blood into the of the heart muscle and may cause blood clots to right ventricle (lower chamber), which form in the heart. This can lead to a stroke. in turn pumps blood to the lungs. This is where the blood picks up oxygen. The left There are a number of treatment options for people living with atrial fibrillation aimed at reducing the symptoms of the arrhythmia and reducing the risk of serious complications. These options can be discussed with any of the physicians at the Al-Sabah Arrhythmia Institute. side of the heart then collects the oxygenrich blood through four pulmonary (lung) veins into the left atrium. When the left atrium contracts, blood is pushed into the left ventricle. The ventricle in turn, pumps the blood to all parts of the body. For this complex pump to operate efficiently, it needs an electrical wiring system that keeps all four chambers properly synchronized. generated. The electrical signal leaves the sinus node and disseminates through both atria (upper chambers) resulting in a coordinated contraction pushing the blood into the lower chambers. Following this, the signal is received by another node called the atrio-ventricular (AV) node. The AV node passes the signal to the ventricles which then contracts soon after the atria contracts. These sets of 1 Under normal circumstances an electrical coordinated contractions are known as impulse is generated in the sino-atrial Normal Sinus Rhythm. In sinus rhythm node (or sinus node). This area is the there is efficient movement of blood heart s natural pacemaker and it responds through the heart and out to the lungs and appropriately to your physical or emotional the rest of your body. It also produces the state by increasing or decreasing the rate at familiar lub-dub of a normal heart beat. which the electrical impulses are
What is atrial fibrillation? Types of atrial fibrillation 2 Unlike normal sinus rhythm, atrial fibrillation is characterized by disorganized, nearly continuous, and widespread electrical activity throughout the upper chambers of the heart. As a result, the upper chambers (atria) do not contract in an organized fashion as described above. Furthermore, the lower chambers (ventricles) are bombarded with rapid, irregular impulses from the atria. This causes the ventricles to beat quickly and erratically. This may result in a variety of symptoms including: Uncomfortable fluttering sensation inside the chest, or chest pain Shortness of breath Fatigue Sweating Chest pressure Dizziness (fainting, rarely) Decrease in the ability to exercise Sudden unexplained anxiety If the heart is forced to beat too fast for long periods of time, the heart muscle can begin to weaken leading to heart failure. Also, because the atria are no longer activated in an organized fashion, there is stagnation of blood within these chambers resulting in blood clots. These blood clots can then travel from the heart to the brain resulting in a stroke. For many people with AF, the arrhythmia comes and goes. This is known as paroxysmal atrial fibrillation. Generally episodes last less than 24 hours; however, sometimes they can last for a few days before spontaneously converting to a normal rhythm. When an episode lasts more than 7 days, this is known as persistent atrial fibrillation. Atrial fibrillation is called longstanding persistent when it lasts for longer than a year. While some patients with paroxysmal A-fib continue to have the arrhythmia only intermittently, many patients progress to persistent and long-standing persistent AF. Patients with all types of atrial fibrillation including paroxysmal may be highly symptomatic and are still at risk for stroke.
Management of atrial fibrillation As mentioned before, patients with A-fib have an increased risk of stroke. This risk can be lowered by the use of blood thinners. However, blood thinners may increase the risk of bleeding. Therefore, these two risks (bleeding versus stroke) must be weighed and balanced for each patient. Factors that increase the risk of stroke in atrial fibrillation include, among others, congestive heart failure, high blood pressure, advanced age, diabetes, and a prior history of stroke. In some patients who have few or no risk factors for stroke, only aspirin is needed to thin the blood. In others who are at a higher risk, blood thinners such as Coumadin (warfarin), rivaroxaban (Xarelto), dabigatran (Pradaxa), or apixaban (Eliquis) may be used. Restoring sinus rhythm can be achieved initially with medications and/or a procedure called cardioversion. Cardioversion is an electrical shock delivered under anesthesia that resets the heart and frequently converts AF to sinus rhythm. Most patients will require medical therapy in order to maintain sinus rhythm after a cardioversion. For patients who are intolerant of medications, in whom the medications do not work, or for those who develop heart failure from atrial fibrillation, catheter ablation may be useful to achieve control of the arrhythmia. 5 In addition to thinning the blood, other medications may be used to control the heart rate while in A-fib and prevent the development of heart failure. The goal is to lower the average heart rate to below 110 beats per minute. This is called rate control. Some patients remain symptomatic despite adequate control of the heart rate. In these patients, the goal is to restore normal sinus rhythm and eliminate symptoms.
Catheter ablation for atrial fibrillation More than a decade ago it was observed the procedure. Electrophysiologists use a that rapid electrical impulses originating number of tools to guide the movement of in cardiac muscle of the pulmonary veins the catheters within the heart. (which drain into the left atrium) could These include: trigger atrial fibrillation. Catheter ablation Flouroscopy helps localize the catheters aims to alter the tissue of the heart in within the heart using X-rays. order to eliminate those triggers. This is Intracardiac echocardiography (ICE) 6 done by delivering radiofrequency energy to tiny areas within the heart muscle using very thin catheters which come in direct contact with the tissue. The energy denatures the tissue which eventually forms a scar and does not conduct electrical activity. This is called radiofrequency ablation. In ablation for atrial fibrillation, electrophysiologists perform the procedure to electrically isolate the pulmonary veins and any other areas that may be triggering AF from the rest of the heart. images throughout the procedure helping your doctor see the other catheters and the detailed structures of the heart. The other catheters record detailed electrical activity in different areas of the heart. Two catheters are advanced through a thin portion of the muscle separating the right and left atrium (the septum) in order to access the left atrium and pulmonary allows visualization of detailed structures and catheters within the heart. Intracardiac electrograms are recordings of the hearts electrical activity made by catheters from within the heart. These are used to guide the ablation procedure and to verify complete isolation of the pulmonary veins and other structures. 3-D mapping system: A number of mapping technologies may be employed that allow for visualization of the catheters within the heart. These systems work as a GPS to localize the catheter position and The series of lines at the bottom of the figure represent electrical recordings from a catheter placed near the entrance of a pulmonary vein during an ablation procedure. On the left hand side of the screen each heart beat results in a recording of electrical activity first in the left atrium (LA) and then in the pulmonary vein (PV). On the third beat, the electrical impulse no longer travels into the pulmonary vein because it is electrically isolated from the procedure. 7 The procedure is performed under general veins. These catheters are used to map the are accurate to within millimeters. anesthesia in a specialized area of the arrhythmia and perform the ablation. The Using these systems, detailed maps of hospital called the electrophysiology lab. catheters are maneuvered systematically the heart can be created to guide and During the procedure catheters are inserted into the large veins of the leg and/or the neck. From there, they are placed in the heart. One catheter has an ultrasound at its tip allowing for continuous ultrasound within the left atrium and elsewhere until all the pulmonary veins are electrically isolated and all the triggers for atrial fibrillation are identified and ablated. No tissue is cut or removed during catalog areas of ablation. These images may also be integrated with a CT scan or MRI of the heart performed prior to the procedure. An image created using a mapping system during an atrial fibrillation ablation procedure. This is a view of the left atrium from behind and all four pulmonary veins are visible. The red dots represents points at which radiofrequency energy was applied to isolate the veins. Two large circles were created to isolate the left and right veins in pairs.
How can I be evaluated for catheter ablation of atrial fibrillation? What can I expect after the ablation procedure? 8 To determine if a catheter ablation is appropriate for you, a thorough evaluation will be performed by members of our team at the Al-Sabah Arrhythmia Institute. This may include: A review of your medical history and a physical examination Electrocardiograms (EKGs) Echocardiogram or other cardiac imaging such as an MRI or CT scan Ambulatory EKG monitoring (Holter or event recorder) Evaluation for coronary artery disease If it is determined that you are a candidate for catheter ablation, and you wish to proceed with the procedure, members of our team will assist you in scheduling any tests needed prior to the procedure. During the first few months following your procedure you will be given a device to send recordings of your heart rhythm to our office. This will allow us to monitor you and make any adjustments to your medications. Depending on your response to the procedure, it is common to require repeat EKGs in our office, ambulatory EKGs at home, echocardiograms and blood work following the procedure. Our staff at the Arrhythmia Institute will closely follow and assess the outcome of your procedure. During the first 3 months after the procedure, you may experience recurrent atrial fibrillation. This may be due to inflammation in the heart from the ablation and does not necessarily mean the procedure did not work. If after 3 months, you are still experiencing atrial fibrillation or a related rhythm called atrial flutter, a repeat ablation may be required. Our team is dedicated to providing you with the best possible care before, during, and after your procedure. We are always a phone call away for any questions, concerns or suggestions you may have. Al-Sabah Arrhythmia Institute: 212-523-2400
Frequently asked questions What are the risks of the procedure? Catheter ablation for atrial fibrillation is generally very safe. As with any invasive procedure there are some risks. We take every Will I be given anesthesia? The procedure is performed under general anesthesia supervised by an anesthesiologist. You will not feel anything during the precaution to minimize these risks during the procedure, and procedure and may not remember some of the events all risks will be discussed with you in detail by your doctor prior immediately following it. to the procedure. How successful is ablation for the treatment of atrial fibrillation? Success rates for atrial fibrillation ablation can be as high as 90%. This varies for each individual and your doctor can give you a more accurate assessment during your visit. How long is the procedure? What can I expect after the procedure? The procedure typically lasts between 2-4 hours. After the procedure, you will be observed closely in a recovery area for 2-3 hours. You must stay in bed for six hours in order Should I take my medications before the procedure? Do not discontinue any of your medications without first talking to your doctor. You may be asked to stop taking certain medications, such as those that control your heart rate. to prevent bleeding from the sites where the catheters were inserted. You will spend the night in the hospital and most patients will leave the following day. 10 If you have diabetes, ask the nurse how you should adjust your medications and insulin for the day of the procedure. You will be instructed to continue taking your blood thinner prior to the procedure. How will I feel after the procedure? You may feel fatigue or minor chest discomfort for 48 hours following the procedure. Please call your doctor if you experience other symptoms such as shortness of breath, bloating, or bleeding. 11 Can I eat? Eat a normal meal the evening prior to the procedure. DO NOT eat or drink anything after midnight including gum, mints, water, etc. If you were instructed to take or continue medications, take them with a small sip of water. Will I be able to drive home? No. For your safety, someone else must drive or accompany you home. If you live more than two hours from the hospital, we suggest you stay in a nearby hotel overnight. If you have a long ride home, please stop every hour and walk for five to ten What should I wear the day of the procedure? Wear comfortable clothes. You will change into a hospital gown for the procedure. Remove all makeup and nail polish and leave all jewelry including wedding rings and watches at home. minutes. If you are flying home, you may want to order a wheelchair to take you on and off the plane. During the flight, be sure to stretch your legs in the aisle for a few minutes every hour. All patients What should I bring with me? Bring your prescription medications with you. You may also want to bring a robe or toiletries with you. Please give them to your family member who can keep them for you until after the procedure. When can I shower after the procedure? should avoid heavy lifting or strenuous activity for 5-7 days. You can shower when you go home. Do not take baths or swim for five days after the procedure.
Frequently asked questions When can I return to my normal activities? You can walk around and return to work after 48 hours so long as you can avoid heavy lifting for 5-7 days. What symptoms should I expect after the procedure? You may experience skipped heartbeats or short episodes of AF during the first three months after the procedure. These symptoms are common and due to inflammation of the heart tissue. After the heart has healed, these should subside. What symptoms should I report? Please call us immediately if you have a fever of higher than 101 degrees; bleeding, redness, swelling or drainage at the site of the procedure. Also let us know if you have any symptoms of AF and use the heart monitor to record your rhythm during these periods. 12 Can I stop taking a blood thinner following the procedure? For at least a few months following the procedure, you will need to continue taking a blood thinner. Following this, you and your doctor will determine if and when it is safe to discontinue a blood thinner. When should I resume other medications? Upon discharge from the hospital, all the medications that you should be taking will be reviewed. Most patients will resume previous medications that were used to control AF. Often, these medications will be stopped or tapered about 3-4 months after the ablation.