Catheter Ablation: 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. 1 , 2 , 3 , 4 , 5 A successful PVI also reduces the threat of death by 50%. 6 (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. 7 The first published studies of Focal Ablation (Pulmonary Vein Ablation) within the Pulmonary Veins came from Bordeaux 8 and Taipei. 9
Definition of “Cured”
Being “cured” of A-Fib is defined as restoring patients to normal sinus rhythm without dependence on any medications. 10 (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.)
Pulmonary Vein Ablation (Isolation) (PVI) is currently the best technique available for “curing” A-Fib. 11 ,12 ,13 It is currently the only treatment for A-Fib which offers hope of a cure (but see also the next section on Surgery).
Catheter Ablation Procedure
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.)
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 for FDA approved catheter devices can be Radio Frequency, RF (heat), or CryoBalloon (freezing). 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.
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.This 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.
Methods to Locate and Isolate A-Fib Signals
The challenge for doctors is how to locate and eliminate A-Fib signals when the patient is not in A-Fib. Research has shown that most A-Fib signals come from the openings (ostia) of the four Pulmonary Veins in the left atrium.
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 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. The newer form of circular ablation uses a balloon catheter and cryo (freezing) energy to encircle the vein opening and make the circular lesions. 14 Other energy sources such as laser and ultrasound balloon catheters are in development.
Segmental Catheter Ablation
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. 15 ,16 ,17 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, 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.)
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. 18 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.)
Permanently A-Fib Free?
Catheter Ablation (and the different Maze surgical operations) is currently the only strategies 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. Research tracking catheter ablations 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 since 1998 after a successful catheter ablation.) For a detailed discussion, see Boston AF 2011: Recurrence/Reconduction/Durability of Catheter Ablations.
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.
Last updated: Tuesday, February 25, 2014
References (↵ returns to text)
- Haïssaguerre M. “Electrophysiological End Point for Catheter Ablation of Atrial Fibrillation Initiated From Multiple Pulmonary Venous Foci,” Circulation. 2000;101:p. 1409↵
- Atrial Fibrillation Educational Material,” University of Pennsylvania, 2001, p.7 “Catheter ablation is a low-risk procedure”↵
- Jais, P. “Ablation Therapy for Atrial Fibrillation: Past, Present and Future,” Cardiovascular Research, Vol. 54, Issue 2, May 2002, P. 343↵
- Jaïs, P. NASPE Convention presentation, San Diego, CA, May 8, 2002↵
- Cappato R et al. “Updated worldwide survey on the methods, efficacy, and safety of catheter ablation for human atrial fibrillation.” Circulation: Arrhythmia and Electrophysiology. 2010: 3:32-38. “When analyzed in a large number of electrophysiology laboratories worldwide, catheter ablation of AF shows to be effective in approximately 80% of patients after 1.3 procedures per patient, with approximately 70% of them not requiring further antiarrhythmic drugs during intermediate follow-up.”↵
- “Catheter ablation can successfully cure AF (A-Fib) in up to 80% of patients and reduce mortality by more than 50%.” “Over time, AF (A-Fib) is also associated with an increased risk of death.” Atrial Fibrillation Association “Information Toolkit” CD, Atrial Fibrillation Patient Information.↵
- Haissaguerre, M, Gencel L, Fischer B, Le Metayer P, Poquet F, Marcus FI, Clementy J. Successful catheter ablation of atrial fibrillation. J Cardiovasc Electrophysiol (1994)5:1045–1052.↵
- Hassaguerre M et al. “Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins.” New England Journal of Medicine. 1998;339;659-666.↵
- Chen, SA et al. “Initiation of atrial fibrillation by ectopic beats originating from the pulmonary veins: electrophysiological characteristics, pharmacological responses, and effects of radiofrequency ablation. Circulation. 1999;100:1879-1886.↵
- Jaïs, P. NASPE Convention presentation, San Diego, CA, May 8, 2002.↵
- “In the opinion of the author, the best technique currently available for curing paroxysmal AF (assuming it originates from the pulmonary veins) is segmental isolation of the pulmonary veins by discrete applications of radiofrequency energy at the ostia, guided by pulmonary vein potentials.” Scheinman M. “Nonpharmacological Approaches to Atrial Fibrillation,” Circulation. 2001:103: p. 2120.↵
- Prystowsky E. “Management of Atrial Fibrillation: Therapeutic Options and Clinical Decisions,” The American Journal of Cardiology. Vol. 85 (10A), May 25, 2000, p. 5D.↵
- Olsson S. “Atrial fibrillation – where do we stand today?” Journal of Internal Medicine. 2001;250: p. 19.21Haïssaguerre M. “Successful Catheter Ablation of Atrial Fibrillation,” Journal of Cardiovascular Electrophysiology 5 (1994), pp. 1045-1052.↵
- Natale A. “First Human Experience With Pulmonary Vein Isolation Using a Through-the-Balloon Circumferential Ultrasound Ablation System for Recurrent Atrial Fibrillation,” Circulation. 2000;102:pp.1879-1882.↵
- Haïssaguerre M. “Electrophysiological End Point for Catheter Ablation of Atrial Fibrillation Initiated From Multiple Pulmonary Venous Foci,” Circulation. 2000;101:p. 1409.↵
- Jais, P. “Ablation Therapy for Atrial Fibrillation: Past, Present and Future,” Cardiovascular Research, Vol. 54, Issue 2, May 2002, P. 343.↵
- Jaïs, P. NASPE Convention presentation, San Diego, CA, May 8, 2002.↵
- Pappone, Carlo et al. “Circumferential Pulmonary Vein Ablation for Atrial Fibrillation: the Milan Experience,” Cardiac Electrophysiology and Pacing Unit of the Department of Cardiology, San Raffaele University Hospital, Milan, Italy. 2003. p. 7. “…the term “electroanatomical remodeling” coined by us derives from the fact that circumferential PV ablation, when effective, determines a significant reduction in LA size and improvement in its transport function during follow-up”.↵
- Boston A-Fib Symposium presentation, January 17, 2004.↵
- “Atrial Fibrillation Educational Material,” University of Pennsylvania, 2001, p.7 “Catheter ablation is a low-risk procedure”,↵