[Catheter ablation for atrial fibrillation: clinically established or still an experimental method]

Interventional treatment for atrial fibrillation has been introduced as a therapeutic option since the pulmonary veins (PV) have been discovered as the dominant sources of paroxysmal atrial fibrillation (PAF). Elimination of PV conduction is the initial goal during catheter ablation in this setting. The success rate after the initial procedure varies between 60 and 85 %, with more than 80 % after subsequent interventions. Supported by the current guidelines, interventional treatment of AF is indicated in case of symptomatic arrhythmias refractory to antiarrhythmic treatment. The introduction of the combined, stepwise approach has been another important breakthrough with regard to the treatment of chronic persistent atrial fibrillation (CAF). This strategy includes the combination of all conventional ablation strategies (PV isolation, ablation of complex fractionated atrial electrograms, linear ablation) with the goal of AF termination. The first procedure for CAF treatment is quite frequently also only the first step towards stable sinus rhythm with a favourable outcome after AF termination (> 80 % sinus rhythm). In more than half of the patients predominantly other atrial arrhythmias than AF have to be targeted in a second procedure. This approach is currently under clinical investigation and so far not "clinically established" due to the fact that it is a quite time consuming and challenging procedure even in experienced centres. Future studies may help to identify predictors for procedure failure (e.g. LA size, AF duration, atrial cycle length, spectral analysis) in order to improve patient selection. Additionally, it has to be underscored, that in paroxysmal atrial fibrillation the relatively high recurrence rate after the first procedure still is the subject of further investigations. This aspect might be improved by the introduction of novel strategies (i.e. testing of concealed PV conduction after ablation with adenosine) or new technologies (i.e. robotic navigation) for PAF ablation.