Is it possible to perform a linear lesion with no local electrograms using a three-dimensional mapping system for the ablation of typical atrial flutter?

AIMS: A randomized prospective study to evaluate the efficacy, safety and long-term outcomes of the complete disappearance of local electrograms along the linear lesion using the EnSite NavX three-dimensional mapping system compared to the conventional fluoroscopy-based mapping for the ablation of typical atrial flutter (AFL). METHODS: 83 patients with spontaneous AFL episodes were randomized to the conventional procedure (group I, 41 patients) or to the EnSite NavX three-dimensional mapping system (group II, 42 patients). When bidirectional block was achieved, a renavigation of the ablation line was performed to verify the absence of local potentials along the line. RESULTS: In all patients, bidirectional isthmus block was achieved. Total mean fluoroscopy time was 19.8 +/- 4.1 min and 9.1 +/- 3.5 min (p < 0.001) and radiofrequency (RF) mean fluoroscopy time was 6.9 +/- 1.4 min and 0.6 +/- 0.3 min (p < 0.001), respectively, in group I and II. During long-term follow-up of 16 +/- 9 months, there were 4 (10%) AFL recurrences in group I and 0 in group II (p < 0.005). CONCLUSION: NavX accurately renavigates the lesion line and verifies local potentials. The electro-anatomic activation map accurately identifies gaps in the RF lesion line and no recurrences were found compared with 10% recurrences after standard procedures for typical AFL.

Is it possible to create a linear lesion with no local electrograms? Comparison between a three-dimensional mapping system and conventional fluoroscopy for cavotricuspid isthmus ablation of typical atrial flutter.

OBJECTIVE: The aim of this prospective, randomised study was to evaluate the efficacy, safety and long-term outcomes of the complete disappearance of local electrograms along the linear lesion using the EnSite NavX three-dimensional mapping system as compared with conventional fluoroscopy for ablation of typical atrial flutter (AFL). METHODS: Seventy-three patients with spontaneous AFL episodes were randomised to undergo fluoroscopy-guided (group I, n=35) or EnSite NavX-guided (group II, n=38) ablation. When bidirectional isthmus block was achieved, the catheter was navigated back along the ablation line to assess the presence of local potentials along the lesion line. RESULTS: Bidirectional isthmus block was achieved in all patients. Mean total fluoroscopy time was 19.8 +/- 4.1 min in group I and 9.1 +/- 3.5 min in group II (P<0.001); mean fluoroscopy time required for radiofrequency ablation was 6.9 +/- 1.4 min in group I and 0.6 +/- 0.3 min in group II (P<0.001). During a follow-up of 16 +/- 9 months, three patients in group I (10%) experienced recurrence of AFL as opposed to none in group II (P<0.005). CONCLUSIONS: NavX technology allows accurate re-navigation of the lesion line to assess the presence of local potentials during an ablation procedure for typical AFL. Electroanatomic activation mapping can accurately identify gaps in the linear radiofrequency lesion with no AFL recurrence compared with 20% of recurrences after a standard procedure.