What is Radio Frequency Ablation?
Ablation is a procedure that destroys the specific area of the heart that begins the abnormally fast signals. First, the specific area of the heart that is causing the abnormal signals is located (endocardial mapping). Then, either radiofrequency waves or small incisions are used to destroy or stop that heart tissue from sending any signals.
Ablation can be done by either using a catheter or during open-heart surgery that is being done for another medical condition.
With catheter ablation, a small, flexible tube (catheter) is inserted into a vein and guided into the heart. When the specific heart tissue is located, the tissue is destroyed -- either by heat (resulting from short bursts of radiofrequency or laser energy) or by small cuts that create scars.
Catheter ablation is a painless, outpatient procedure involving local anesthesia.
With surgical ablation, a person is already having open-heart surgery for another medical condition. During the open-heart surgery, the area of the heart causing the tachyarrhythmia is ablated using many small cuts.
In many cases, ablation cures the arrhythmia. For patients with ventricular tachycardia or some atrial arrhythmias, ablation may be the only cure.
Kinds of Catheter and Surgical Ablation Procedures for Atrial Fibrillation
When atrial fibrillation (AF) cannot be controlled with medications or cardioversion, or if the symptoms of AF become unbearable, ablation is used. Depending upon your type of atrial arrhythmia, your doctor may recommend one of these procedures:
Atrial Fibrillation: Ablate and Pace
When the electrical pathway between the atria and ventricles (the atrioventricular node or AV node) is causing the atrial fibrillation, catheter ablation may be used. A small, flexible tube (catheter) is inserted into a vein and guided into the heart. Heat created with radiofrequency waves destroys the tissue.
The broken pathway prevents an arrhythmia from traveling from the upper heart chambers (atria) to the lower heart chambers (ventricles). However, this procedure often makes the normal heart rate too slow. A pacemaker is then placed inside the body to make the heart beat at a rate needed to supply the body with the amount of oxygen needed for daily activities, including exercise.
Ablation of the AV node is not a cure. It often decreases many of the symptoms of AF. However, the atria continue to beat rapidly and irregularly (AF), so there is still the risk of stroke. As a result, blood-thinning medications are prescribed. Many studies have reported that people enjoy a better sense of well-being following this procedure.
Atrial Flutter: Catheter Ablation
This procedure treats atrial flutter by delivering a small amount of electrical energy through a soft tube (catheter) positioned inside the heart through your veins. This electrical energy interrupts the fast circuit and eliminates the arrhythmia. With current techniques, atrial flutter can be eliminated in 90% of cases. In 5 to 10% of these people, atrial flutter can return. Other people, especially those with significant heart disease, may develop atrial fibrillation that requires medication.
Atrial Fibrillation: Linear and Focal Catheter Ablation
This kind of ablation procedure uses catheters to make small scars on the inside of the upper chambers (atria) of the heart. The catheters are inserted through the veins and guided to the inside of the heart. This type of ablation is done to destroy the specific cells that are starting or contributing to AF.
Surgical Ablation during Open-heart Surgery
A surgical approach to the treatment of AF, called the MAZE procedure, is an open-heart operation. It is used only for those patients whose AF cannot be controlled by other therapies (medications and cardioversion) and for those people who are undergoing open-heart surgery for other reasons. This procedure involves making many incisions or ablation lines in the atria or upper chambers to regain normal rhythm. Sometimes a pacemaker is needed.
Like any open-heart surgery, this surgery requires general anesthesia and hospitalization for a week or more. Although the number of patients who have undergone the MAZE procedure is relatively small, many have achieved long-term freedom from AF.