Ablation Therapy to Treat Atrial Fibrillation

Atrial fibrillation (A-fib) is one of the most common heart arrhythmias, affecting millions of people in the United States 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 your risk of stroke. Unfortunately, its treatment often remains a real problem for both healthcare providers and patients.

Overview

The most sought-after treatment for A-fib has been one that cures the arrhythmia with ablation. Ablation is a procedure that maps, localizes, and destroys the source of the patient’s heart arrythmia by creating scarring inside the heart to interrupt the irregular rhythm. It is performed either during an electrophysiology study (a test to assess your heart’s electrical system) or in the surgical suite.

Generally, ablation is accomplished by applying radiofrequency energy (cauterization) or cryoenergy (freezing) through a catheter (a thin tube), to destroy a small area of cardiac muscle in order to disrupt the arrhythmia. While many types of cardiac arrhythmias have become readily curable using ablation techniques, atrial fibrillation has remained a challenge.

Difficulties

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

Going After Triggers

Electrophysiologists have learned they can often improve atrial fibrillation by ablating the "triggers" of the arrhythmia, namely PACs (premature atrial contractions, 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 by using a special catheter designed for this purpose, atrial fibrillation can often be reduced in frequency or even be 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 healthcare providers 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 likely than it used to be.

Effectiveness

Despite recent advances, the ablation of A-fib 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 doesn't work as 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 (three-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.

Additionally, the successful ablation of atrial fibrillation has been shown to reduce the risk of strokes.

Complications

The risk of complications with catheter ablation for atrial fibrillation is higher than it is for other kinds of arrhythmias. This is because for A-fib, the ablation procedure tends to take substantially longer, the scars needed to be produced tend to be larger, and the location of the scars that are produced (in the left atrium, usually near the pulmonary veins) increases the risk of complications.

Procedure-related death occurs in between 1 in 5 of every 1,000 patients having an ablation for atrial fibrillation. The serious complications that can lead to death include cardiac tamponade (extra fluid buildup around the heart), stroke (blood supply to the brain is interrupted), producing a fistula (an abnormal connection) between the left atrium and the esophagus, perforation of a pulmonary vein, and infection.

Potential complications include stroke, damage to a pulmonary vein (which can produce lung problems leading to severe shortness of breath, cough, and recurrent pneumonia), and damage to other blood vessels (the vessels through which the catheters are inserted). 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.

A Word From Verywell

Anyone with atrial fibrillation who is being asked to consider ablation therapy ought to keep a couple of important facts in mind. First, the success rate of the procedure, while reasonably good, is not measurably better than it is with anti-arrhythmic drugs—at least, not after a single ablation procedure. Second, there is a very slight 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 anti-arrhythmic drugs have failed.

Just be sure that if you are considering an ablation procedure for A-fib, 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 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 healthcare provider has a lot of experience and has a good safety record and good past results with ablation procedures for atrial fibrillation.