Pulmonary vein isolation for atrial fibrillation

Atrial fibrillation can be caused by electrical signals that originate in the area around the pulmonary veins. If this is the case, catheter ablation can be used to isolate the pulmonary vein from the left atrium. This is referred to as pulmonary vein isolation.

What is pulmonary vein isolation?

Pulmonary vein isolation is a minimally-invasive catheter-based electrosurgical technique for the treatment of atrial fibrillation. The purpose of treatment is to prevent a recurrence of the symptoms of atrial fibrillation. Pulmonary vein isolation should be considered in patients who remain symptomatic despite optimal pharmacological therapy.

Pulmonary vein isolation prevents electrical signals from the pulmonary veins from reaching the left atrium. The pulmonary veins are responsible for producing frequent electrical signals (triggers) that cause atrial fibrillation. Ablation can isolate the triggers produced in the pulmonary veins, thus stopping them from reaching the atrium and triggering atrial fibrillation.

3D-mapping image showing the precise anatomy of the left atrium. The image is produced using CT data obtained with the NavX mapping system.

What happens during pulmonary vein isolation?

Catheter ablation offers a potential treatment option in patients with symptomatic paroxysmal atrial fibrillation.

3D reconstruction showing the anatomy of the left atrium (shaded in blue). The image is produced using CT data, and allows precise anatomical mapping in patients with challenging or abnormal anatomy.

Prior to the procedure

Certain tests may be required prior to the actual procedure. These will provide the technical data necessary for the procedure, as well as helping to make the procedure safe. The decision as to which types of tests are required is made on a case-by-case basis.

Trans-thoracic (TTE) and trans-esophageal (TEE) echocardiography - an ultrasound examination to establish the precise anatomy of the heart.
MRI (magnetic resonance) imaging or CT (computed tomography) scanning to establish the precise anatomy of the left atrium. Amongst other things, these imaging data will be used to produce a 3D reconstruction during the procedure.
Significant disruptions to normal blood flow through the heart need to be ruled out. If in doubt, left heart cardiac catheterization (coronary angiography) may be required

The examination takes place in a specially equipped catheterization laboratory - our electrophysiology laboratory. Prior to undergoing the actual procedure, you will be connected to a number of different monitors (e.g. ECG). This allows continuous monitoring of your heart function throughout the procedure.

During the procedure

The procedure is performed using local anesthesia. In most cases, additional drugs will be administered that also induce sleep (procedural sedation).  

A catheter is inserted into the femoral vein and advanced toward the heart. It enters the right atrium via the vena cava, passing through the septum into the left atrium.   
Once the left atrium and the pulmonary veins have been visualized using contrast agents, a special computer-guided system is used to produce a 3D mapping image of the left atrium. This image is then used as a guide throughout the remainder of the procedure.  

Once the relevant area has been successfully ablated, the procedure is often interrupted for a considerable period of time in order to determine whether the ablated tissue is likely to recover. At the end of the procedure, the catheters are removed.  The procedure normally takes between 2-4 hours.

Robotic catheterization procedure (Sensei X - Hansen Medical)

In our hospital, we have the option of performing this procedure using a robotic navigation system. This allows the physician to operate the catheters remotely, from a control room, reducing radiation exposure for both the patient and the operator. In addition, catheter stability is improved, which may make difficult-to-reach areas more accessible. The decision as to whether robotic navigation is a viable option must be made on a case-by-case basis.

After the procedure

The patient remains in the catheterization laboratory while a pressure bandage is being applied, and will need to remain in bed for a number of hours after the end of the procedure. It will be necessary for the patient to be closely monitored for at least one day after the procedure.

Discharge from hospital

It is usually possible for patients to be discharged from the clinic a day or two after the procedure.

At home

After discharge, you should try to avoid physical activity for a duration of one week.

Once a tiny incision has been made in the septum, the catheters are advanced into the left atrium. The left atrium is then explored using special catheters, which provide the data necessary to produce an anatomically correct image of the atrium, with exact measurements on the location of the pulmonary vein ostia (shown in color). This helps to make pulmonary vein isolation less technically challenging, as well as making it safer for the patient.

Ablated areas are represented by near-continuous red lines. Ablation results in almost complete isolation of the pulmonary veins. Results of the successful catheter ablation procedure are visualized using the NavX 3D mapping system. At the Brandenburg Heart Center, this system is used in all patients undergoing pulmonary vein isolation.

Where can I find out more about pulmonary vein isolation?

General information

Deutsche Herzstiftung (German Heart Foundation)

herzstiftung.de

Deutsche Gesellschaft für Kardiologie (German Cardiac Society)
dgk.org

Kompetenznetz Vorhofflimmern (The German Competence Network on Atrial Fibrillation, AFNET)
kompetenznetz-vorhofflimmern.de

Sources

Leitlinien, Deutsche Gesellschaft für Kardiologie - Katheterablation [Guidelines, German Cardiac Society - Catheter Ablation]

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