The Basics of Catheter Ablation for Atrial Fibrillation

Today catheter ablation is considered a first-line strategy choice in patients with Atrial Fibrillation and is vastly superior to using antiarrhythmic drugs first to treat Atrial Fibrillation symptoms.

During a catheter ablation, the heart is beating and in constant motion (unlike open-heart surgeries when a heart-lung machine temporarily takes over the work of the heart and lungs).

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

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).

Catheter ablation is a relatively painless procedure, because there are no nerve endings in the smooth tissue of the heart and veins.

3D Imaging to Detect A-Fib Signals

Electrophysiologists (EPs) use Fluoroscopy, a special type of X-Ray, along with imaging systems to see inside the heart.

Sensors on specialized mapping catheters record electrical activity from multiple heart walls at once. Computer software builds a digital 3D model of your heart anatomy which highlights the chaotic electrical signals.

3D images of heart with inset image of sensor tip of catheter.

Location and Isolation of Atrial Fibrillation Signals

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

Energy Sources: Today’s catheter devices differ by their energy source: heat (Radio Frequency), freezing (CryoBalloon) and electrical pulses (Pulsed Field Ablation).

Illustration: A left atrial pulmonary vein ostium and sleeve.

RF Energy Ablation Lesions: One technique is to make circular radiofrequency (RF) ablation lines around each pulmonary vein opening. This isolates the pulmonary veins (PVs) from the rest of the heart and prevents any pulses from these veins from getting into the heart.

Or, EPs may make one large oval lesion encircling and isolating two PVs at the same time (called Wide Area Antrum Circumferential Isolation).

Cryo Energy Ablation Lesions: Another technique to form a circular ablation uses a balloon catheter and cryo (freezing) energy to encircle the vein opening and make the circular lesions.

3D Ablation Map of heart: White dots are RF lesions. Notice the continuous line formed.

Note: Timing of your ablation is more important than the energy source used. Getting an ablation within the first 12 months after diagnosis improves outcomes, i.e., before significant remodeling can alter your heart.

Locating More A-Fib Signals: Pulmonary Vein Potentials

A different method of locating and eliminating A-Fib signals 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.

The Final Check: Induce A-Fib/Flutter with Drugs

As a final check after the Pulmonary Vein potentials or PV triggers are isolated, the EP will try to induce A-Fib (or Flutter) by the use of drugs such as Isoproterenol or Adenosine. (Hopefully, A-Fib will not recur.) 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 other areas of abnormal electrical activity 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.

Best Technique Available for Curing Your A-Fib

A catheter ablation, and specifically a Pulmonary Vein Ablation (PVA), is currently the best technique available for “curing” A-Fib. It is currently the only minimally invasive treatment for A-Fib which offers hope of a cure.

Pulmonary Vein Ablation techniques are achieving success rates of 70%-85% in making Paroxysmal A-Fib patients A-Fib free. With a second ablation, for Persistent A-Fib, for example, the success rates rise to over 90%.

Ablation Benefits Even If Not Cured: The other 15%-30% of catheter ablation patients, 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.)

VIDEO: What is Catheter Ablation? (click image to watch)

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 assists the physicians in viewing the anatomy and electric system of the heart. (2:33) By Swedish Heart & Vascular Institute. (Or, Watch on YouTube)

To learn more about Catheter Ablation, see our page, Catheter Ablation For Atrial Fibrillation (Pulmonary Vein Ablation/Isolation).

If you find any errors on this page, email us. Y  Last updated: Saturday, August 29, 2026

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