Ablating Atrial Fibrillation

The pros and cons of ablation therapy for atrial fibrillation

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Atrial fibrillation is one of the most common heart arrhythmias, affecting millions of people in the U.S. alone. It is a rapid, irregular heart rhythm originating in the atrial (upper) chambers of the heart, commonly causing palpitations and fatigue. It greatly increases the risk of stroke.

Unfortunately, its treatment often remains a real problem for both doctors and patients.

    Ablating Atrial Fibrillation

    The Holy Grail in the quest for treating atrial fibrillation has been to develop a way to cure the arrhythmia with ablation. Ablation is a procedure performed either during an electrophysiology study or in the surgical suite, in which the source of a patient's heart arrhythmia is mapped, localized, and then destroyed (i.e., ablated.) Generally, ablation is accomplished by applying radiofrequency energy (cauterization) or cryoenergy (freezing) through a catheter, to destroy a small area of cardiac muscle in order to disrupt the arrhythmia. While many forms of cardiac arrhythmias have become readily curable using ablation techniques, atrial fibrillation has remained a challenge.

    Why Has Ablating Atrial fibrillation Been So Difficult?

    Most cardiac arrhythmias are caused by a small, localized area somewhere within the heart that produces an electrical disruption of the normal heart rhythm.

    For most arrhythmias, then, ablation simply requires locating that small abnormal area and disrupting it.

    In contrast, the electrical disruptions associated with atrial fibrillation are much more extensive - essentially encompassing most of the left and right atria.

    Early efforts at ablating atrial fibrillation were aimed at creating a "maze" of complex, linear scars throughout the atria, to disrupt this extensive abnormal electrical activity.

    This approach (which has been called the maze procedure) works reasonably well when performed by very experienced surgeons in the operating room - but it requires major open-heart surgery, with all the associated risks. Creating the linear scars necessary to disrupt atrial fibrillation is much more difficult with a catheterization procedure.

    A Different Approach: Going After the Triggers

    Electrophysiologists have learned they can often improve atrial fibrillation by ablating the "triggers" of the arrhythmia - namely PACs (premature beats arising in the atria).

    Studies suggest that in up to 90% of patients with atrial fibrillation, the PACs that trigger the arrhythmia arise from specific areas within the left atrium, namely, near the openings of the four pulmonary veins. (The pulmonary veins are the blood vessels that deliver oxygenated blood from the lungs to the heart.) If the opening of the veins can be electrically isolated from the rest of the left atrium, using a special catheter designed for this purpose, atrial fibrillation can often be reduced in frequency or even eliminated.

    Furthermore, new and very advanced (and very expensive) three-dimensional mapping systems have been developed for use in ablation procedures in the catheterization lab. These new mapping systems allow doctors to create ablation scars with a level of precision unknown just a few years ago. This new technology has made the ablation of atrial fibrillation much more feasible than it used to be.

    How Effective Is It?

    Despite recent advances, the ablation of atrial fibrillation is still a lengthy and difficult procedure, and its results are less than perfect. Ablation works best in patients who have relatively brief episodes of atrial fibrillation - so called "paroxysmal" atrial fibrillation. Ablation works much less well in patients who have chronic or persistent atrial fibrillation, or who have significant underlying cardiac disease such as heart failure, or heart valve disease.

    Even with patients who appear to be ideal candidates for ablation of atrial fibrillation, the long-term (3-year) success rate after a single ablation procedure is only about 50%. With repeated ablation procedures, the success rate is reported to be as high as 80%. Each ablation procedure, however, exposes the patient once again to the risk of complications. And success rates are much lower with patients who are less than ideal candidates.

    These success rates are roughly the same as those achieved with antiarrhythmic drugs.

    Furthermore, the successful ablation of atrial fibrillation has never been shown to reduce the risk of strokes. So it is important to continue with therapy to prevent strokes even after ablation.


    The risk of complications with catheter ablation for atrial fibrillation is higher than it is for other kinds of arrhythmias. This is because the duration of the ablation procedure tends to be substantially longer with atrial fibrillation, the extent of the scar that must be produced is usually much greater, and the location of the scars that are produced (i.e., in the left atrium, usually near the pulmonary veins), increases the risk of complications.

    Procedure-related death occurs in between one and five of every 1,000 patients having ablation for atrial fibrillation. The serious complications that can lead to death include cardiac tamponade, stroke, producing a fistula (connection) between the left atrium and the esophagus, perforation of a pulmonary vein, and infection.

    Stroke occurs in up to 2%. Damage to a pulmonary vein (which can produce lung problems leading to severe shortness of breath, cough, and recurrent pneumonia) occurs in up to 3%. Damage to other blood vessels (the vessels through which the catheters are inserted) occurs in 1 or 2%. All of these complications appear to be more common in patients over 75 years of age, and in women.

    In general, both the success of the procedure and the risk of complications improve when the ablation is conducted by an electrophysiologist with extensive experience in ablating atrial fibrillation.

    The Bottom Line

    Anyone with atrial fibrillation who is being asked to consider ablation therapy ought to keep a few important things in mind. First, the success rate of the procedure, while reasonably good, is not measurably better than it is with antiarrhythmic drugs - at least, not after a single ablation procedure. Second, even when successful, the benefit of ablation is limited to symptom relief. It does not improve survival, and has not been shown to reduce the risk of stroke. Third, there is a non-negligible risk of serious complications.

    Despite these limitations, it is entirely reasonable to consider an ablation procedure if your atrial fibrillation is producing symptoms that disrupt your life, especially if one or two trials of antiarrhythmic drugs have failed.

    Just be sure that If you are considering an ablation procedure for atrial fibrillation, you make yourself aware of all your treatment options for this arrhythmia.

    If ablation is still an attractive option for you, you will want to make sure you optimize your odds of a successful procedure. This means knowing your electrophysiologist's own personal experience with ablation procedures for atrial fibrillation. Don't settle for a recitation of statistics from the published medical literature (which are generally reported only by the very best centers). Your odds of a good outcome are improved if your doctor has a lot of experience, and personally has a good safety and efficacy record with ablation procedures for atrial fibrillation.


    Ganesan AN, Shipp NJ, Brooks AG, et al. Long-term outcomes of catheter ablation of atrial fibrillation: a systematic review and meta-analysis. J Am Heart Assoc 2013; 2:e004549.

    Cosedis Nielsen J, Johannessen A, Raatikainen P, et al. Radiofrequency ablation as initial therapy in paroxysmal atrial fibrillation. N Engl J Med 2012; 367:1587.

    Morillo CA, Verma A, Connolly SJ, et al. Radiofrequency ablation vs antiarrhythmic drugs as first-line treatment of paroxysmal atrial fibrillation (RAAFT-2): a randomized trial. JAMA 2014; 311:692.

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