Time-limited cryomapping during tachycardia: improved long-term outcomes for cryoablation of AVNRT

Abstract

PurposeCryothermal ablation (CTA) for atrioventricular nodal reentrant tachycardia (AVNRT) is considered safer than radiofrequency ablation (RFA) since it eliminates the risk of inadvertent AV block. However, it has not been widely adopted due to high late recurrence rate (LRR). In an effort to improve LRR, we evaluated a new approach to cryothermal mapping (CTM): “time to tachycardia termination” (TTT).MethodsThis single-center study had 88 consecutive patients who underwent CTA using TTT for AVNRT. The CTA catheter was positioned in sinus rhythm at the posteroseptal tricuspid annulus, and then AVNRT was induced. The CTA target site was identified by prompt tachycardia termination in ≤20 s during CTM. Procedural success was defined as no inducible AVNRT and ≤1 single AV nodal echoes.ResultsAcute procedural success was achieved in 87 of 88 patients (98.9 %) and was similar to prior studies for both CTA and RFA. No permanent AV block was observed. LRR was 3.7 % at a mean follow-up of 19.7 months. LRR was equivalent to that commonly reported for RFA and improved when compared to conventional CTA.ConclusionTTT for CTA of AVNRT provides enhanced safety and similar long-term efficacy when compared to RFA. Based upon this experience, TTT provides an enhancement to conventional CTA that appears to result in improved long-term outcomes. In light of these findings, it seems reasonable to undertake additional randomized trials to determine whether RFA or CTA using TTT is the optimal approach for the catheter ablation of AVNRT.

Fluoroless Catheter Ablation of Cardiac Arrhythmias: A 5‐Year Experience

“…The techniques we employed have been described in detail previously . The technique can be briefly summarized as follows.…”

“…The techniques we employed have been described in detail previously. [17][18][19] The technique can be briefly summarized as follows. If employed, an ICE catheter is advanced to image the heart and is positioned in the right atrium.…”

Safety and efficacy of first‐line cryoablation for para‐hisian ventricular arrhythmias using a cryomapping protocol approach: A case series

“…Furthermore, the efficacy may be explained by a strict cryomapping protocol of the disappearance of VAs within 20 seconds after starting cryomapping. 10 Another study also reported a successful cryoablation for VAs from para-Hisian region. However, cryotest (cryomapping) was attempted before the cryoablation only in 40% of the patients, and detailed approach and mapping protocol of the cryotest were not reported in their study.…”

“…In contrast, we reported that the VAs originating near the His bundle region were successfully eliminated by first‐line cryoablation in all 4 patients. Furthermore, the efficacy may be explained by a strict cryomapping protocol of the disappearance of VAs within 20 seconds after starting cryomapping 10 . Another study also reported a successful cryoablation for VAs from para‐Hisian region.…”

“…When the His bundle potential was visible in the distal electrode of the ablation catheter placed at the earliest activation site, we first evaluated the effect of the elimination of VAs on cryomapping slightly toward to ventricular apex site (below the earliest activation site). The efficacy was defined as the disappearance of VAs within 20 seconds after starting cryomapping 10 . If the effect was poor but no AV block was found, cryomapping was performed by shifting the catheter to the earliest ventricular activation site where the His bundle potential was visible in the distal electrode of the catheter.…”