The effect of NavX on fluoroscopy times in pediatric catheter ablation

Catheter ablation is the established curative therapy for pediatric tachyarrhythmias. However, exposure to ionizing radiation from fluoroscopy during the procedure is of concern to both patients and caregivers. We sought to assess the impact of an impedance-based three-dimensional navigation system (NavX(TM), Endocardial Solutions, Inc., St. Paul, MN) on pediatric catheter ablation procedures. We retrospectively analyzed procedural data during a 7-year period (2002-2008), which spanned the transition between standard fluoroscopic mapping and adoption of NavX(TM) mapping for catheter ablation of atrioventricular nodal reentrant tachycardia (AVNRT) and right/left-sided accessory pathways (RAP/LAP). Comparisons of total procedure time, total fluoroscopy time, and ablation fluoroscopy time (from insertion of ablation catheter until completion of procedure) between NavX(TM) and conventional mapping were made. Three hundred eighty-eight patients (aged 1-18 years, M/F 236:183) underwent ablation of AVNRT (n = 101), LAP (n = 130), or RAP (n = 157) using either conventional (n = 70) or NavX(TM) (n = 318) mapping. Overall success rates were similar between the two mapping approaches (95.7% for conventional versus 95.9% for NavX(TM)). NavX(TM) mapping significantly reduced ablation fluoroscopy time (15.9 +/- 14.3 versus 11.0 +/- 8.9 min for NavX(TM), p < 0.01) with a trend towards a decrease in total fluoroscopy time (26.4 +/- 15.6 versus 23.8 +/- 11.1 min for NavX(TM), p = 0.095). Total procedure time was not significantly different between the two methods (210.1 +/- 66 versus 222.8 +/- 61 min for NavX(TM), p = 0.13). When analyzed by arrhythmia substrate, there were significant reductions in ablation fluoroscopy time for both LAP and RAP. NavX(TM) mapping reduced ablation fluoroscopy times for accessory pathways during pediatric catheter ablation.