The Efficiency of Transcatheter Cryoablation for Treating Atrioventricular Nodal Reentrant Tachycardia.

Objective To observe the efficiency of transcatheter cryoablation of atrioventricular nodal slow-pathway for treating atrioventricular nodal reentrant tachycardia(AVNRT) and compare with the radiofrequency cardiac ablation(RFCA).Methods Thirteen patients with AVNRT underwent transcatheter cryoablation of slow-pathway.Cryomapping was perfomed after cryoadheres to the target point at a temperature of-30℃.-75℃ cryoablation was performed for 4-8 minutes after confirming the target point and no fast-pathway injury.During cryoablation,the atrioventricular nodal conduction was guarded.The cryoablation would be stopped and the target point would be changed as soon as the injury of atrioventricular node had been found.Results Cryoablation was succeeded in all 13 patients and no relapse was found during 1-9 months'follow-up.There was no migration of the joint between the target point and the top of cryoablation catheter at cryomapping and cryoablation.During cryoablation,nodal premature beats and nodal rhythm were not found.Two cases developed complete AV block during cryomapping and cryoablation which disappeared within few seconds after rewarming.There were no other complications.Conclusions Transcatheter cryoablation is an effective therapy for AVNRT.It's safer than RFCA,because its reversible injury decreases the incidence rate of atrioventricular block in special temperature-time range.