6. AVNRT: Electrophysiological Aspects and Ablation Results

Specific Objective We sought to compare the efficacy of the Localisa (L) three dimensional navigation systems in reducing radiation exposure by comparison to a conventional method using fluoroscopy (F) in a consecutive series of patients undergoing Radiofrequency ablation (RFA) of Supraventricular Tachycardia (SVT). Methods and Results 55 patients undergoing RFA (31 male) were studied, (mean age 47[SD ± 16.5]). Patients were randomly assigned to either L (with fluoroscopy as required) or F alone. 52 procedures were completely successful. 26 patients were assigned to F and 29 to L. Indications for RFA were AVNRT in 17 (30.9%), atrio-ventricular nodal ablation in 6(10.9%), cavo-tricuspid isthmus ablation in 10(18.2%) and accessory pathway ablation in 20(36.4%). The mean fluoroscopy time using the F was 20.16 ± 8.3 minutes and 14.90 ± 14.7 minutes using L (p = 0.006). The mean fluoroscopy dosage was 4946 ± 4914 cGY.cm-2 using F and 3280 ± 4458 cGY.cm-2 using L (p = 0.07). The mean RFA time was 5 minutes (± 5.6) with no significant difference with either approach. Conclusion Routine use of the Localisa results in a significant reduction in fluoroscopy and radiation exposure in patients undergoing routine RFA for SVT.