This document updates a report published by SBU Alert in 2005.

Atrial fibrillation is an abnormal irregular heart rhythm (atrial tachyarrhythmia) characterized by a rapid and uncoordinated activation of the upper chambers of the heart (atria), leading to an irregular and unsynchronized activation of the lower chambers (ventricles). Atrial fibrillation is the most com­mon tachyarrhythmia and is often associated with an impaired heart function and an increased risk for embolic stroke.

Although many patients may benefit from anti­ arrhythmic drug treatment, catheter ablation is a treatment option for patients with severe symptoms who do not respond to or cannot tolerate anti­ arrhythmic drugs. Using a special ablation catheter, heat energy can be applied to tissue around the pulmonary veins (pulmonary vein isolation) and, in some cases, to certain areas in the left atrium.

• In patients with severe symptoms of atrial fibril­lation, refractory to conventional treatment with medication, catheter ablation is more effective than continued pharmacotherapy in treating symptoms. Results of follow­ups (up to 12 months) show that patients with paroxysmal atrial fibrillation respond more favourably to catheter ablation than those with persistent atrial fibrillation.
• The catheter ablation treatment carries risks for serious complications, and its risk profile differs from that of continued pharmacotherapy. Hence, it is important that patients who are candidates for catheter ablation receive comprehensive and objective information about the benefits and risks.
• The scientific evidence is insufficient for drawing conclusions about the cost ­effectiveness of the method, since its long­ term effects are uncertain.