Radiofrequency catheter ablation of accessory pathways during entrainment of AV reentrant XXXX .

@entity1 @entity591 @entity2917
Radiofrequency ablation of accessory pathways must sometimes be done during orthodromic @entity2917 when manifest anterograde accessory pathway conduction is absent or retrograde fusion obscures accessory pathway location during ventricular pacing. Unfortunately, abrupt heart rate slowing upon radiofrequency induced termination of @entity2917 often causes catheter dislodgment. We report our experience in circumventing this problem during radiofrequency ablation by using entrainment of @entity2917 . The latter maintains retrograde activation pattern over the accessory pathway while preventing abrupt ventricular rate change. Eight @entity1 (4 @entity1 and 4 @entity1 , mean age 37.3 +/- 17.9) with eleven left-sided accessory pathways were included. Ablation during entrainment was used as the first approach in three @entity1 with concealed accessory pathways and one @entity1 with a bidirectional accessory pathway. In another four @entity1 , ablation during entrainment was used after technical difficulties in ablating during @entity591 . Only 1-3 radiofrequency applications were required to eliminate the accessory pathway using the entrainment technique. The catheter remained stable when accessory pathway conduction was interrupted by radiofrequency current. In conclusion, entrainment of @entity2917 during radiofrequency application is useful for maintaining catheter position for accessory pathway ablation during @entity2917 .
