Abstract 18477: Outcome of Anatomical Approach of Radiofrequency Catheter Ablation for Atrioventricular Nodal Reentrant Tachycardia: 15 years experience

Abstract

BACKGROUND: Even though the anatomical approach as the radiofrequency (RF) ablation for atrioventricular nodal reentrant tachycardia (AVNRT) has been introduced long ago, large population based outcome of this approach remains unclear. Moreover, electrophysiologic characteristics between different successful target sites have not been identified as well. The purpose of this study was to investigate outcome and electrophysiologic characteristics according to successful target site. METHODS: A total of 1391consecutive patients (mean age 45±16 years, female 63%) who underwent RF catheter ablation based on anatomical approach for AVNRT between 1996 and 2010 were enrolled in this study. The tricuspid annulus between the coronary sinus ostium and the His bundle recording site was divided into posterior (P), medial (M), and anterior (A) regions. Serial RF energy applications were delivered from P site to superior side until junctional rhythm was inducible. RESULTS: Dual AV nodal physiology was documented in 91.9 %, typical AVNRT was 92.4 %. The mean procedure time, fluoroscopic time, and the ablation time was 63±28 min, 12±7 min, and 226±176 sec, respectively. Successful target site was P in 46.7% (n=684), M in 47.9% (n=701), and A in 0.7% (n=5). Long-term recurrence rate was 1.8% (n=25). AV nodal block requiring pacemaker occurred in 0.2 % (n=3). When divided into two groups, A (successful ablation at P site) and B (successful ablation at M and A sites), there was no difference between two groups in age, gender, tachycardia cycle length, atrial effective refractory period (ERP), AV block cycle length (BCL), ERP of fast and slow pathway, ventricular ERP, temperature, RF power, and long-term recurrence (all p values > 0.05). However, group A had more atypical form (9.4% vs. 6.0%, p=0.019), longer shortest VA interval (30.0±1.35 vs. 24.5±1.13 msec, p=0.002), longer VA BCL (376±102 vs. 361±88 msec, p=0.007), and shorter RF time (180±121 vs. 317±226 sec, p<0.001) than group B. CONCLUSION: Anatomical approach of RF ablation for AVNRT showed excellent long-term outcome. The electrophysiologic characteristics were different according to successful ablation site.