Arrhythmia Center
Stockholm

Ablation of Atrial Fibrillation

 

Which patients can be considered for AFib ablation?

According to the European and American guidelines of treatment of atrial fibrillation from 2010, patients with pronounced symptoms can be considered for catheter ablation if one or more antiarrhythmic medications (eg, Tambocor, Multaq, or amiodarone) have not had proper effect, or if side effects occur. In 2012 the guidelines where updated and ablation can be offered as a first line treatment for patients who don´t wish to try antiarrhythmic drugs.

The theory behind the treatment

In the late 90's a research team in Bordeaux, France, showed that the vast majority of atrial fibrillation starts due to extra beats that occur in or adjacent to the vessels running between the lungs and the left atrium, the so-called pulmonary veins. Why these extra beats occur in some people and cause atrial fibrillation is not yet known. By isolating these regions from the left atrium approximately 70% of the patients improved or was completely free from fibrillation.

The Ablation Procedure

kateter


The procedure is done by a so-called catheterization. This means that thin wires (catheters) are placed in the heart, inserted under local anesthesia, through a vessel in the groin. The catheter used for the treatment itself, is transferred to the left atrium through the septum between the atria. Often one or more catheters are placed in the heart. With the help of a computer program, a three-dimensional image is created of the left atrium and pulmonary veins. After this, the actual ablation starts by the catheter tip, which is heated, and passed around the pulmonary veins whereby these are isolated from the rest of the atrium (Figure 1). Some parts of the atria are pain-sensitive and analgesic drugs and sedatives are given during the procedure, but general anesthesia is rarely used. Sometimes an extended treatment of the atria is necessary, especially if the palpitations have existed for a long time. The entire procedure takes about 3-6 hours.

We have chosen to work with a form of robotics, so-called Stereotaxis (Figures 2 and 3). This means that the treating catheter is controlled by magnets surrounding the patient.

labbildFig. 2. Our lab

StereotaxisFig. 3. Click to enlarge

After the procedure, the patient lies in bed for about 4 hours and is usually discharged from the hospital the following day. After about a week, the patient can return to full activity, including work. It is quite common that the patient has a lot of atrial fibrillation, particularly during the first three-month period, after an ablation. Because of this, the patient normally continues with regular medication for another three to six months. If the atrial fibrillation returns during this period a cardioversion and adjustment of medication may be necessary. This does not mean that the ablation is a failure and needs to be redone. After about three months of stable heart rhythm, the patient may quit the stabilizing medical treatment.


Results

The result of an ablation is largely dependent on the type of atrial fibrillation the patient suffers from. If the patient have had atrial fibrillation for a long period of time and/or is persistent, the results are less successful. There are many indications that the chances of success with an ablation is greater the earlier in the "atrial fibrillation career" the procedure is done. If the atrial fibrillation attacks are brief and ends spontaneously, the possibility is significantly larger for a successful treatment. On average, one can expect that about 70% of treated patients are free from symptoms and do not need to eat medicine. To achieve this success rate, sometimes more than one procedure is needed.

Complications

Complications associated with an atrial fibrillation ablation occur in 1-5% of all procedures. With modern technology, the risk is much lower, and we have for the first 1400 ablations a complication rate of 0.4%. Because of the quite high dosages of anticoagulant during surgery, one of the most common complications is bleeding or discomfort from the groin. Rarely a bleeding into the pericardial sac occurs, which in some cases may need to be drained. Although anticoagulant is administered during surgery, there is a small risk of stroke or clots to other organs. Previous techniques meant that they gave treatment near the pulmonary veins with the risk of strictures in them. With current technology, the risk of this complication is significantly lower.