Catheter Ablation
Catheter ablation was performed with a 4 mm tip non-irrigated radiofrequency ablation catheter or a 3.5 mm saline cooled catheter. For temperature-controlled delivery, power was titrated from 30-50 W with a temperature limit of 50° to 60° for a duration of 60-90 seconds to achieve accelerated junctional beats with intact AV and VA conduction. For the saline cooled catheter, power was initiated at 20-25 W and titrated up to 35 W while monitoring accelerated junctional beats. Ablation endpoints were lack of inducibility of AVNRT and no more than single slow-fast AV nodal echo beats with programmed stimulation in either the basal state or during isoproterenol infusion.