Ablation
About ablation and catheter ablationAblation is a procedure to destroy very small, carefully selected parts of the heart that are causing tachycardia – an abnormally fast heartbeat. Ablation enables the heart to beat more slowly and normally again. Although there are several forms of ablation, the two most common are radiofrequency ablation and cryoablation.
Radiofrequency ablation uses radio energy to heat and destroy the defective tissues. It is by far the most common form of ablation.
Cryoablation uses intense cold to freeze and destroy the tissues. As with radiofrequency ablation, cryoablation involves insertion of a catheter through a blood vessel and up to the heart. However, rather than delivering radiofrequency energy, a highly specialized catheter produces extreme cold in the area. This causes tiny ice crystals in and around the abnormal cells, destroying those cells.
What to Expect Before
Catheter ablation is usually done in a specially equipped room, called an electrophysiology (EP) lab. Sometimes these procedures are performed in a cardiac catheterization (cath) lab.
Normally you’ll be taken to the EP lab on a movable bed and then shifted onto a table. This special table is also movable and has a special fluoroscopic camera over it. This camera (a fluoro) is like an x-ray video camera. There is other equipment in an EP lab, including viewing screens, heart monitors, and emergency equipment. Once on the table, you will be connected to several types of monitoring equipment and then be covered with a sterile drape.
There are usually several EP lab staff members present during the procedure, including one or more electrophysiologists (a cardiologist with special training), nurses, and technicians.
A staff person will shave and cleanse the area where the catheters will be inserted. In most cases this will be the groin or neck area. To numb the area, a local anesthetic is injected into the skin with a tiny needle.
A small intravenous (IV) needle will be inserted into a vein in your arm and connected to an IV line. This allows medications to be administered if necessary.
Many times you will be awake during the procedure, although medication is often given to help you relax and be more comfortable; however, some people may fall asleep during the procedure. The staff will monitor you constantly.
Complications & Risks
Because ablation procedures require the insertion of catheters into the body, they do involve some risk.
Some patients can have bleeding, swelling, or bruising where the catheters were inserted. Serious complications do sometimes occur. These include infection, damage to the heart or blood vessels, and blood clots. Death is very rare during these procedures.
It is also possible that the heart’s normal electrical system could be damaged during this procedure. If this occurs, an artificial pacemaker implant may be necessary.
Occasionally the arrhythmia will require accessing the left side of the heart. This will require getting to the left heart by either trans-septal catheterization or retrograde aortic catheterization. Trans-septal catheterization requires using a specialized needle to puncture the atrial septum (the divider between the right atrium and the left atrium) at an area called the fossa ovalis to access the left atrium. Retrograde catheterization requires passing the catheter across the aortic valve in order to place it in the left ventricle. Since clots on the left side of the heart could travel to the heart arteries or brain to cause heart attacks or strokes, it is essential to treat the patient with high doses of blood thinners during the procedure. This decreases the risk of the terrible complications of heart attack, stroke and other emboli, but can increase the risk of bleeding, particularly around the heart (cardiac tamponade).
Most patients who undergo catheter ablation do not experience complications, but you should be aware of the risks. If you have any questions about potential risks or your particular condition, ask your physician.
What to Expect During
A small incision is made in the numbed skin; again, this is usually in the groin or neck area. A needle is used to puncture the blood vessel (typically a vein, but sometimes an artery) into which an ablation or diagnostic catheter, or both, will be inserted.
One or more diagnostic catheters are inserted into your blood vessel and gently moved toward the heart. Your physician will follow catheter progress on a special monitor connected to the fluoroscope camera.
Diagnostic catheters can be used to sense electrical activity in various areas of the heart and measure how fast these impulses travel. These catheters can also be used to deliver tiny electrical impulses to stimulate the heart to beat or contract. By doing so, physicians attempt to start (or induce) your tachycardia so they can understand more about it and decide how best to treat it. If you feel the same symptoms you experienced when the arrhythmia occurred previously, you should tell the electrophysiology (EP) lab staff.
Often these induced arrhythmias stop by themselves; however, if an arrhythmia persists or is very rapid, it may make you feel faint for a moment. If this happens, your doctor may need to deliver electrical therapy to the heart to stop the abnormal rhythm. If you were not in an EP lab these arrhythmias could be very dangerous, perhaps even life-threatening. The well-trained personnel in the EP lab, however, have the equipment and medications necessary to respond appropriately and immediately to these arrhythmias.
The catheter ablation procedure is usually not painful. You may feel some pressure at the sites where the catheters are inserted. It is also not unusual to experience some mild chest discomfort during the application of the high-frequency energy, which is the actual ablation part of the procedure.
Most catheter ablation procedures are completed within two hours, but occasionally a procedure can last up to six hours or more, which means that you may feel tired and uncomfortable after lying still for such a lengthy period of time. It is important for family to realize that after leaving the holding area, the patient undergoes more extensive, timely preparation work and the procedure will appear longer to those who are sitting in the waiting room.
What to Expect After
All of the catheters will be removed when the procedure is done. Firm pressure will be applied at the catheter insertion sites for several minutes to prevent bleeding, and a dressing will be applied.
You will be disconnected from most of the monitoring equipment, but some of this equipment may remain connected until you have been transported to a recovery area or hospital room. The intravenous (IV) line in your arm is often left in place.
You will be required to lie flat and still for several hours. You should avoid lifting and bending your legs where the catheters were inserted. This will give the punctured vessels an opportunity to heal completely.
Typically a nurse follows your progress for several hours by checking your pulse, blood pressure, and the catheter insertion sites. If you notice bleeding or feel pain at these insertion sites, or if you feel your heart beating rapidly, notify the nurse immediately.
Sometimes you will be allowed to go home on the day of the procedure, but you may be required to stay in the hospital overnight. The heart may be monitored with an electrocardiogram (ECG) until you go home. You should make arrangements for someone to take you home from the hospital.
After you return home, limit your activity for several day. Avoid all vigorous physical exertion and strain (such as lifting heavy objects). In addition, carefully follow your physician’s instructions regarding medications you are to take.
Leave the dressing in place until the next day or as instructed by your physician or nurse. He or she will also tell you how long to wait to bathe after returning home.
It is not unusual to have a bruise or small lump where the catheters were inserted. This usually disappears in a week or two. It is unusual for the sites to become warm to the touch, tender, painful, or for any swelling to increase after you return home. It would also be unusual for you to develop a fever or experience a recurrence of your rapid heart rhythm, chest pain, dizziness, or shortness of breath. If any of these occur, contact your physician immediately.