Ablation 

Radio frequency ablation or ablation is a nonsurgical procedure used to treat some types of rapid heart rhythms. Rapid, uncoordinated heartbeats which start in the heart's upper chambers (atria) or middle region (AV node or the very beginning portion of the heart's electrical system), can often be controlled by this procedure.

During the ablation, a physician guides a catheter with an electrode at its tip to the area of heart muscle where there's an accessory pathway. Then a mild, painless radiofrequency energy (similar to microwave heat) is transmitted to the site of the pathway. Heart muscle cells in a very small area (about 1/5 of an inch) die and stop conducting the extra impulses that caused the rapid heartbeats.

Radiofrequency ablation has a low risk of complications. It causes little or no discomfort and is done under mild sedation with local anesthesia.