Regarding the ablation there are two types available the first uses a cauterizer that attempts to "burn" the area of the AV node that is the problem. The second is a cryogenic version. The people that I know that have had this done seem to have good results. As the procedure was described to me you are awake and the cardiologist stimulates various places in the AV node area to try to throw the heart into arythmia. Having found the area it is then cryogenically destroyed.