Catheter Ablation: Pulmonary Vein Ablation (Isolation)

Catheter ablation of the pulmonary veins

Current Pulmonary Vein Ablation techniques are achieving success rates of 70%-85% in making Paroxysmal A-Fib patients A-Fib free with low risk. A successful PVI also reduces the threat of death by 50%. (Check with your particular heart center for its success rate.)

This is a relatively new procedure. The first journal published report of a successful catheter ablation for A-Fib in humans was done in 1994 in Bordeaux, France.  The first published studies of Focal Ablation (Pulmonary Vein Ablation) within the Pulmonary Veins came from Bordeaux and Taipei.

Definition of “Cured”

Being “cured” of A-Fib is defined as restoring patients to normal sinus rhythm without dependence on any medications.  (The other 15%-30%, though not “cured” of A-Fib, may be significantly improved after an ablation. They may have fewer or less intense attacks of A-Fib; medications that didn’t work before may now control the A-Fib. But for some there may not be any noticeable improvement at all.) (As a point of reference, the National Cancer Society considers someone cured of cancer if they are in remission for 5 years.)

Pulmonary Vein Ablation (Isolation) (PVI) is currently the best technique available for “curing” A-Fib. It is currently the only treatment for A-Fib which offers hope of a cure (but see also the next section on Surgery). Each year, 400,000 patients around the world benefit from a catheter ablation.

VIDEO: What is catheter ablation? Dr. Darryl Wells, explains two ways catheter ablation is used to eliminate the triggers of A-Fib and how 3-dimensional mapping to assist the physicians in viewing the anatomy and electric system of the heart. (2:33) Uploaded to YouTube by Swedish Heart & Vascular Institute.

For more videos visit our Library of A-Fib Videos including:

When Drug Therapy Fails: Why Patients Consider Catheter Ablation (3:00), and Catheter Ablation For A-Fib: What it is, How it’s Done and What Results Can Be Expected (4:00).

Catheter Ablation Procedure

Catheter inserted into the heart and through septum wall into Left Atria

During a catheter ablation, a soft, thin, flexible, coated tube with an electrode at the tip is inserted through a large vein in your groin and moved into your heart. (The catheter is about the width of the lead in a pencil, while the vein is about the size of your little finger.) These catheters can be inserted in both your right and left groins, and sometimes in your neck as well (for monitoring).

This catheter is directed to the precise location(s) in your heart that are producing your A-Fib. These points are burned off or isolated from your heart.

The energy sources catheter devices use currently are Radio Frequency, RF (heat), CryoBalloon (freezing), Laser and Ultrasound (in development). For more about energy sources, see A CryoAblation Primer.

Doctors use Fluoroscopy, a special type of X-Ray, or other imaging systems to see inside the heart and map where A-Fib signals are coming from.

Catheter ablation is a relatively painless procedure, because there are no nerve endings in the smooth tissue of the heart and veins. However, one reader wrote me that they felt a lot of pain from the ablation burns.

If you are in A-Fib during the Catheter Ablation procedure, doctors can determine where the A-Fib signals are coming from and ablate (remove) them. However, if you have intermittent A-Fib (Paroxysmal A-Fib), it’s harder to pinpoint and map exactly the source(s) of the A-Fib signals.

Doctors now prefer a patient to be in sinus rhythm during the ablation. They use modern mapping techniques to find and ablate areas with A-Fib “potentials”—an electrical charge or energy capable of producing an A-Fib/Flutter signal.

Methods to Locate and Isolate A-Fib Signals

Research has shown that most A-Fib signals come from the openings (ostia) of the four Pulmonary Veins in the left atrium.

Circumferential Ablation

One technique is to make Circular Radiofrequency (RF) Ablation lines around each pulmonary vein opening (called “Circumferential Ablation” or “Pulmonary Vein Antrum Isolation” [PVAI]). This isolates the pulmonary veins (PVs) from the rest of the heart and prevents any pulses from these veins from getting into the heart.

Instead of making circular ablation lines around each PV, EPs now make Wide Area Antrum (Circumferential) Isolation oval lesions encircling and isolating two PVs at the same time (WACA).

A newer form of circular ablation uses a balloon catheter and cryo (freezing) energy to encircle the vein opening and make the circular lesions. Other energy sources such as laser balloon and ultrasound catheters are also used or are in development.

Schema of the left atrial-pulmonary vein ostium. Muscular extensions of the left atrial tissue into the pulmonary veins may serve as the originating foci of premature atrial beats and pulmonary vein atrial tachycardias. It is these foci that lead to the initiation and perpetuation of atrial fibrillation. Catheter ablation at the left atrial-pulmonary vein junction serves to electrically isolate the pulmonary veins, thereby trapping these foci that are now unable to excite the left atrium.

Segmental Catheter Ablation—Pulmonary Vein Potentials

A different method of locating and eliminating A-Fib signals (called “Segmental Catheter Ablation”) uses Pulmonary Vein Potentials. A potential is an electrical charge or energy—like the battery energy in your car. Even if your car isn’t running, you can still measure 12 volts “potential” at the battery. Similarly, in your heart any potential in a pulmonary vein area can be measured and pinpointed, even if you aren’t in A-Fib at the time.

When the area is ablated, the potential disappears. Like taking the battery out of your car, removing this potential eliminates your A-Fib. As mentioned above, this technique can achieve success rates as high as 85% with low risk for people with Paroxysmal A-Fib.  For people with Chronic A-Fib, success rates may not be as good.

Instead of ablating inside the Pulmonary Vein Openings which may risk Stenosis (swelling which impedes blood flow from the lungs), the pathways taken by these A-Fib signals from the Pulmonary Veins are located and ablated outside of the Pulmonary Vein openings. The A-Fib Pulmonary Vein potentials or sources of A-Fib signals are thus disconnected and isolated from the rest of the heart.

In the pulmonary veins (PVs) there are cardiac muscular sleeves which reach from the left atrial tissue into the PVs. These sleeves contain cells with spontaneous electrical activity which usually beat in sync with normal sinus and AV Node signals. They share a similar embryological origin. But in A-Fib they may beat on their own creating A-Fib signals which need to be isolated from the rest of the left atrium.

Ablation map: the white dots represent the point-by-point RF ablation burns (made from inside the heart) isolating the pulmonary veins. Notice that there are no gaps. (This patient has five pulmonary veins instead of the usual four.) Image provided by Dr. Alexander Dtril, Houston Arrhythmia Associates.

During an ablation procedure, after the Pulmonary Vein Potentials or PV Triggers are isolated, the doctor will try to induce A-Fib/Flutter by the use of drugs such as Isoproterenol or Adenosine. All too often other A-Fib Potentials or Trigger sites are found outside of the Pulmonary Veins. These have to be tracked down, mapped, and ablated/isolated. Sometimes potentials or foci are not visible during the procedure because the pulmonary vein triggers suppress or hide them. That’s why many EPs wait a half hour before proceeding to allow these potentials or possible gaps to appear.

The goal is to eliminate all these sites so that A-Fib/Flutter can no longer be induced. (Thanks to Daniel Jachimczyk for this clarification.)

Anatomically-Based Circumferential Pulmonary Vein Ablation (Left Atrial Ablation)

Another procedure for isolating A-Fib signals is called “Anatomically-Based Circumferential Pulmonary Vein Ablation” by Dr. Carlo Pappone of Milan, Italy who first developed this technique. It is also called “Left Atrial Ablation” by Dr. Fred Morady of the Un. of Michigan. 19 Instead of concentrating on the Pulmonary Veins and Pulmonary Vein Potentials, the emphasis is on creating blocking lesions in the left atrium similar to “Circumferential” ablation described above.

But instead of trying to make continuous, perfect linear lesions, a large diameter catheter at a high wattage is dropped and dragged to make the circular linear lesions. There may be gaps left in these lesions which may result in Atrial Flutter. But over time scar tissue usually closes these gaps (see Boston AF 2004/Morady and Boston AF 2003/Pappone). (At the 2008 Boston A-Fib Symposium Dr. Pappone’s presentation showed nearly continuous, perfect linear lesions with very few gaps.)

Pulmonary Vein Ablation (Isolation) is a low risk procedure but it is not risk free. For a more in depth look at the actual risks involved, see Risks Associated with Pulmonary Vein Procedure.

Permanently A-Fib Free?

Catheter Ablation (and the different Maze surgical operations) is currently the only strategy offering the hope of becoming A-Fib free permanently.

A “successful” ablation or surgery, though, may not be permanent. The problem is called recurrence (or reconduction). Heart tissue is very hardy. Over time ablation scars can heal over and allow A-Fib signals to again disrupt the heart. Older research tracking catheter ablations indicated there was an approximately 7% chance of recurrence/reconnection each year out to five years. Since A-Fib ablation is a relatively new procedure, we don’t have figures for longer than five years. (The author has been A-Fib free since 1998 after a successful catheter ablation.) For a detailed discussion, see Boston AF 2011: Recurrence/Reconduction/Durability of Catheter Ablations.

Some estimate that there is approximately a 15% chance of recurrence, but that often depends on the skill, techniques, and experience of the EP. That’s why you want to go to an EP and A-Fib center with a high volume and good success rate. Don’t just go to an EP because they are near you. Go to the best you can find and reasonably afford to travel to. See https://a-fib.com/catheter-ablation-high-volume-low-compications/.

If recurrence occurs, catheter ablations can be repeated (but Cox Maze and Mini-Maze surgeries can not).

The Hybrid Surgery/Ablation Procedure

Relatively new is the Hybrid Surgery/Ablation Procedure in which a surgeon and a cardiac electrophysiologist (EP) team up to work together on the same patient. The genius of the Hybrid approach seems to be its complementary nature: the surgeon on the outside the heart and the EP on the inside the heart. (Similar multidisciplinary ablation techniques are ‘hybrid ablation technique’, ‘convergence process’, ‘Convergent Maze Procedure’ and ‘Convergent Ablation”’.)

Read more about the Hybrid Surgery/Ablation Procedure under “Cox Maze, Mini-Maze & Hybrid Surgeries“.

Steve’s List of Doctors by Specialties

Over the past decade, the number of heart centers in the U.S. performing catheter ablations for A-Fib on a regular basis has steadily grown (the number of international centers has increased too.)

See Doctors & Facilities/Steve’s Lists Doctors by Specialties and more specifically, US EPs with FHRS-designation Performing A-Fib Ablations by US State/City.

If you find any errors on this page, email us. Y Last updated: Monday, January 31, 2022

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