Atrial Fibrillation

PULMONARY VEIN ABLATION (ISOLATION)

      Current Pulmonary Vein Ablation techniques are achieving success rates of 70%-85% in making Paroxysmal A-Fib patients A-Fib free with low risk.^{17,33,34,41,243} A successful PVI also reduces the threat of death by 50%.²⁸³(Check with your particular heart center for its success rate.) "Curing" A-Fib is defined as restoring patients to normal sinus rhythm without dependence on any medications.⁴¹ (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.)
    Currently the only catheter devices FDA approved for the treatment of A-Fib are Radio Frequency and CryoBalloon. See FDA Approves First Ablation Catheter for A-Fib and FDA APPROVES CRYOBALLOON ABLATION CATHETER

     Pulmonary Vein Ablation (Isolation) is currently the best technique available for "curing" A-Fib.^18,19,20

    During Pulmonary Vein 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. 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. (To see a news video of this procedure, go to http://newyork.cbslocal.com/2010/08/24/healthwatch-a-fib/). 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. (The catheter is about the width of the lead in a pencil, while the vein is about the size of your little finger.)
    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.²¹ The first published studies of Focal Ablation (Pulmonary Vein Ablation) within the Pulmonary Veins came from Bordeaux⁴⁷ and Taipei.⁴⁸) Currently, many heart centers in the U.S. are doing Pulmonary Vein Ablation (Isolation) of A-Fib on a regular basis. (For a partial list of these facilities, see Doctors/Facilities.)
    This is a relatively painless procedure, because there are no nerve endings in the smooth tissue of the heart and veins. However, someone recently wrote me that they felt a lot of pain from the ablation burns.
    If you are in A-Fib during the Catheter Ablation procedure, it's relatively easy for the doctors to determine where the A-Fib signals are coming from and to 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.
    The challenge for doctors is how to locate and eliminate A-Fib signals when the patient is not in A-Fib. Since research has shown that most A-Fib signals come from the openings (ostia) of the four Pulmonary Veins into the left atrium, one technique is to make Circular Radiofrequency (RF) Ablation lines around each pulmonary vein opening (called "Circumferential Ablation"). This isolates the pulmonary veins from the rest of the heart and prevents any pulses from these veins from getting into the heart. However, it's difficult to make circular RF lesions and they aren't always successful. (A new technique of circular ablation uses a balloon catheter and cryo (freezing) energy to encircle the vein opening and make the circular lesions.²²Other energy sources such as laser and ultrasound balloon catheters are in development.)

Pulmonary Vein opening (ostium) showing A-Fib PV triggers. Muscular extensions of the left atrial tissue into the pulmonary veins may develop into focal PV triggers where premature atrial beats and A-Fib signals originate. These foci initiate A-Fib signals. Catheter Ablation at the left atrial-pulmonary vein junction electrically isolates the pulmonary veins, thereby trapping these A-Fib signals so that they can not excite the left atrium. (From http://www.washingtonhra.com/41.html Dr. Pirooz Mofrad.)

    A different method of locating and eliminating A-Fib signals (called "Segmental Catheter Ablation") uses Pulmonary Vein Potentials. A potential is Car Battery 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.^17,34,41 For people with Chronic A-Fib, success rates may not be as good. (See Chronic A-Fib.)
    Instead of ablating inside the Pulmonary Vein Openings which may risk Stenosis, 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 disconnected from the rest of the heart.
    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. 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. 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.)

    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 technique⁵⁸. It is also called "Left Atrial Ablation" by Dr. Fred Morady of the Un. of Michigan⁶⁰. 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 Morady and 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 procedure³³, but it is not risk free. For a more in depth look at the actual risks involved, see Risks in the FAQs section.

PERMANENTLY A-FIB FREE?
Catheter Ablation (and the different Maze surgical operations) are currently the only strategies offering the hope of becoming A-Fib free permanently. But there is a problem with recurrence/reconduction after a "successful" ablation and surgery. Heart tissue is very hardy. Over time ablation scars can heal over and allow A-Fib signals to again disrupt the heart. Recent research indicates there is 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 for 12 years after a successful catheter ablation.) For a detailed discussion, see RECURRENCE/RECONDUCTION/DURABILITY OF CATHETER ABLATIONS

Disclaimer: the authors of this Web site are not medical doctors and are not affiliated with any medical school or organization. The information on this site is not intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health professional prior to starting any new treatment or with any questions you may have regarding a medical condition. Nothing contained in this service is intended to be for medical diagnosis or treatment.

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(This page last updated 1/03/11)