Slow Atrioventricular Nodal Pathway Ablation: Electrocardiogram Monitoring During Effective Delivery of Radiofrequency Energy / 中山大学学报(医学科学版)

ABSTRACT

【Objective】 To explore the significance of electrocard iogram monitoring during the effective application of radiofrequency energy to s low atrioventricular (AV) nodal pathway ablation. 【Methods】 Slow AV nodal pathway ablation was performed in 58 patients with slownfast AV nodal ree-trant tachyca rdi a (AVNRT). The changes of electrocardiogram were monitored during the effective application of low radiofrequency RF energy (15～25 W). A faster rate of junctio nal ectopy (>150 min-1), ventriculoatrial (VA) block in association with j unctional ectopy, and l ong P-R interval during sinus beat were considered as harbingers of atrioventri cular (AV) block. RF energy deliveries were discontinued as soon as the harbinge rs of AV block occurred. Otherwise, RF energy continued until junctional ectopie s were decreased or vanished. If junctionnal ectopies were not decreased, RF ene rgy continued lasted for 90～120 s. 【Results】 Slow AV nodal pathway ablation w as successful in all patients who had junctional ectopy during the effective del ivery of RF energy. The effective ablation time was (128±26) s. 54 patients exp erienced one time successful ablation, and 4 patients experienced two times abla tion. Unsustained AV block occurred in 6 patinets after RF energy deliveries whi ch were immediately terminated because of VA block in association with junctiona l ectopy in 4 patinets and long P-R interval during sinus beats in 2 patients. No patients developed permanent AV block. Recurrent AVNRT requiring second ablat ion occurred in 2 of 58 successfully ablated slow pathway during (18±16) months of follow-up. 【Conclusion】 RF energy deliveries could be instructed b y intracardiac electrocardiogram monitoring during AVNRT ablation, which could e nhance the successful rate of slow pathway ablation, reduce recurrence and avoide permanent AV block.