Electroanatomic activation mapping for atrioventricular nodal reentry tachycardia ablation: a safe and innovative method in a new era

Abstract Background Catheter ablation of slow pathway (SP) is the treatment of choice for symptomatic patients with episodes of atrioventricular nodal reentry tachycardia (AVNRT). Purpose We sought to evaluate a new technique to identify and ablate SP by using late activation mapping with CARTO 3 (CARTO PRIME V7, Biosense Webster). Methods We obtained Koch triangle 3D activation map in 76 patients (65.8% females, mean age 51.4± 14.4 years) using THERMOCOOL SMARTTOUCH SF ablation catheter (Biosense Webster©, Inc., Irvine, CA, USA). His potential and coronary sinus ostium were accurately marked. During sinus rhythm we generated endocardial voltage gradient and late activation time (LAT) maps. A conventional decapolar catheter was positioned in the CS and a quadripolar on the His bundle. A window of interest (WOI) was set from −200 to +30 ms relatively to P wave using CS ARA (Advanced Reference Annotation). The point where the latest atrial activation was identified at the LAT map, was considered as SP position and was targeted for ablation. The low-voltage bridge was obtained from the voltage gradient map. Results The mean total time of procedure was 66.4 ± 24.9 minutes and the mean mapping time was 27.1 ± 6.3 minutes. The mean RF ablation time was 73.8 ± 59 seconds and the mean RF applications were 3.7 ± 2.7. The mean ablation index was 374 ± 86. The mean contact force was 7 ± 2.2 grams and the mean resistance drop was 8.6 ± 3.7 Ω. No patient experienced any complications during the procedure, and there was no recurrence during the 12-month follow-up. Conclusions SP ablation using 3D activation mapping via CARTO3 V7 system is an innovative, safe, effective and fast alternative for AVNRT ablation. The use of this technique allows SP ablation with minimal radiation, a very small number of energy applications and zero complications from conduction system damage, due to its clear mapping and delineation.Late activation and low voltage SP map