AV Node Ablation

Atrioventricular (AV) node ablation is a medical procedure used to treat atrial fibrillation (AF), a condition where the atria (the chambers at the back of the heart) beat irregularly.

This procedure is typically performed when other methods of managing the symptoms or the rate of AF have not been successful.

Procedure

AV node ablation is performed in two stages, typically 3-4 weeks apart. If you have a pacemaker already, the AV node ablation may be performed at any time.

Step 1:

1. Pacemaker insertion: A pacemaker is inserted, which sends electrical impulses to the ventricles. This pacemaker does not improve symptoms, but allows for the AV node ablation to be performed. If your heart function is normal, a ‘normal’ pacemaker is used; if your heart function is reduced, you may receive a specific pacemaker (called CRT) that maintains synchronous contraction of the heart.

Step 2:

2. AV node ablation: A thin wire (catheter) is inserted into the femoral vein in the groin area and threaded to the heart. An electrode at the tip of the catheter delivers current to the AV node to “burn” it, preventing electrical signals from traveling from the atria to the ventricles. The atria remain in fibrillation, but the ventricles no longer respond. The pacemaker then takes over to deliver a controlled and regular heart rate.

Advantages

Advantages of the procedure include a stable and regular heart beat, and the ability to stop taking certain medications used to manage the symptoms of AF. Most patients will feel much better.

Disadvantages

The main disadvantages include the need for two separate hospital admissions separated by 3-4 weeks, and the fact that the ablation does not “cure” AF, so anticoagulant medication will still be needed. Additionally, there are small risks from the procedures themselves.

Once the AV node ablation is performed, you will be dependent on the pacemaker, and the ablation cannot be reversed. However, modern pacemakers are very reliable and are monitored daily.

Risks

The nature and risks of pacemaker implantation are detailed here.

The risks of AV node ablation include:

• bleeding at the catheter site
• perforation of a heart chamber, or the wall of a blood vessel, requiring surgery
• dislodgement of a pacemaker lead
• dependence on a pacemaker for life
• pacing induced cardiomyopathy - where pacing of the heart weakens the heart muscle; in this case the pacemaker would be upgraded to a cardiac resynchronisation device
• the risk of a very serious complication including stroke, heart attack, or emergency surgery is less than 1 in a 1000