Electrophysiology CINRE, hospital BORY
Atrial Fibrillation: Guidelines (2026) Compendium / 14.1 Ablation of Atrial Fibrillation – Principle and Methods

Ablation of Atrial Fibrillation – Principle and Methods

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Ablation means removal or deactivation of tissue using heat, cold, or another source of energy.

  • In cardiology, three methods are used for ablation of atrial fibrillation (AF) and other arrhythmias:
    • Radiofrequency ablation – myocardial destruction by heat
    • Cryoablation – myocardial destruction by freezing
    • Pulsed field ablation – myocardial destruction by electrical impulses
Diagram comparing catheter ablation techniques for atrial fibrillation, including cryoablation, radiofrequency ablation, and pulsed field ablation, highlighting different mechanisms of lesion formation in the atrial myocardium.
Atrial fibrillation ablation – methods (basic comparison)
Radiofrequency ablation
  • Principle: The catheter tip is heated (~50 °C).
  • Methodology: Lesions are created point by point around each pulmonary vein.
  • Procedure time: 90–180 min.
  • Complications: Atrio-oesophageal fistula, phrenic nerve injury, pulmonary vein stenosis.
Cryoablation
  • Principle: The catheter has a balloon at its tip, which is advanced into the pulmonary vein at the ostium.
  • Methodology: The balloon at the ostium of each vein is frozen (~ −50 °C).
  • Procedure time: ~60 min.
  • Complications: Phrenic nerve injury.
Pulsed field ablation
  • Principle: The catheter is expanded at its distal end into a “sphere” or “flower” shape at the pulmonary vein ostium.
  • Methodology: Electrodes on the catheter deliver short electrical impulses (electroporation).
  • Procedure time: ~60 min.
  • Complications: Minimal, virtually none.
Diagram comparing paroxysmal and persistent atrial fibrillation illustrating differences in the distribution of arrhythmogenic foci within the atrial myocardium and corresponding ECG manifestations.

AF ablation and pulmonary vein isolation

  • AF initially presents as paroxysmal and originates (90%) in the region of the pulmonary vein ostia, where both the AF trigger and substrate are located in close proximity.
    • Electrical impulses from the pulmonary vein ostia, from the activated substrate, propagate into the left atrium.
    • Initially, this mechanism manifests clinically as paroxysmal AF.
  • After several years, the substrate extends to other areas of the left atrium (roof, posterior wall, mitral isthmus).
    • This expanded substrate manifests clinically as persistent AF.
  • Pulmonary vein isolation (regardless of the method used) electrically isolates both the trigger and the substrate at the ostia.
    • Therefore, pulmonary vein isolation is most effective in paroxysmal AF.
  • If the substrate is also present outside the pulmonary vein ostia (persistent AF),
    • more extensive ablation is performed (roof, posterior wall, mitral isthmus, superior vena cava).
Diagram of atrial fibrillation illustrating the location of triggers and the arrhythmogenic substrate in the left and right atria, including pulmonary vein ostia, the left atrial appendage, and the posterior wall.

Pulsed field ablation (basic procedure)

  1. Sheaths are inserted into the femoral veins in the groin (2 left, 1 right), through which catheters are advanced via the inferior vena cava into the right atrium:
    • Left side: intracardiac echocardiography (ICE), catheter in the coronary sinus.
    • Right side: transseptal puncture needle.
  2. Under ICE guidance, a transseptal puncture is performed through the fossa ovalis.
  3. Subsequently, the ablation catheter is advanced through the fossa ovalis into the left atrium.
    4. Diagram of an ablation catheter during atrial fibrillation ablation illustrating basket and flower catheter configurations used for pulmonary vein isolation.
  4. A dedicated catheter is used for pulsed field ablation,
    • which is deployed in the left atrium in a “flower” configuration with 5 splines,
    • each spline contains 4 electrodes (positive and negative).
    • During pulse delivery, a strong electric field is generated between the positive and negative electrodes,
      • causing movement of ions and electrons between the electrodes.
    • Particles pass through cardiomyocyte membranes and create pores,
      • a process termed electroporation, leading to destruction of the myocardium and the arrhythmogenic substrate.
    Diagram of atrial fibrillation ablation illustrating isolation of the left superior pulmonary vein with placement of the ablation catheter in basket and flower configurations.
  5. The catheter is sequentially positioned in each pulmonary vein, first in the oval (basket) configuration and subsequently in the “flower” configuration.
    • Electrical pulses are delivered in both configurations.
  6. Pulsed field ablation is cardioselective:
    • it induces irreversible electroporation of cardiomyocytes and the arrhythmogenic substrate,
    • surrounding tissues (vessels, nerves, oesophagus) remain unaffected.
Atrial fibrillation ablation Class
Pulsed field ablation (not radiofrequency or cryoablation) is recommended as the preferred method of atrial fibrillation ablation. I

These guidelines are unofficial and do not represent formal guidelines issued by any professional cardiology society. They are intended for educational and informational purposes only.

Peter Blahut, MD

Peter Blahut, MD (Twitter(X), LinkedIn, PubMed)