Ablation of focal atrial fibrillation

In the past decades management of atrial fibrillation (AF) has been based mainly on drug therapy. New insights into the pathophysiology of AF initiation and maintenance have provided the background for the design of catheter based procedures. The crucial role of the pulmonary veins (PVs) as triggers of AF paved the way for successful mapping and ablation. Electrical isolation of all PVs using the circular mapping approach has been shown to be an effective procedure, with reported success rates around 70 to 80% in most series. Intracardiac echocardiography is a very helpful adjunctive tool to facilitate correct positioning of the circular catheter at the PV-left atrial junction, as well as to monitor energy delivery and assist transseptal left atrial access. PV stenosis is a potential serious complication, occurring in around 2% of cases. It presents mainly with respiratory symptoms, although it is frequently asymptomatic. Spiral computed tomography is a reliable non-invasive method for imaging the PVs and can be used to screen patients for PV stenosis after radiofrequency ablation. In symptomatic patients, PV dilatation and stenting is the preferred treatment approach. The possibility of curing AF represents a major breakthrough in invasive cardiac electrophysiology. Isolation of all PVs is a very solid endpoint for successful ablation and should be pursued in all patients. It seems to be associated with high success rates over long term follow-up. Future refinements in catheter technology should provide simpler and faster procedures and render catheter ablation of AF more widespread and accepted.