LocaLisa catheter navigation reduces fluoroscopy time and dosage in ablation of atrial flutter:: A prospective randomized study

Introduction: Catheter ablation has become a well-established therapy for isthmus-dependent right atrial flutter (AFL). Recently, mapping and ablation of AFL have been performed using sophisticated three-dimensional mapping systems, such as electroanatomic and noncontact mapping systems. The LocaLisa system enables nonfluoroscopic navigation of intracardiac electrode catheters based on impedance changes related to catheter movements in transthoracic current fields. The aim of this randomized prospective study was to compare the efficacy of the LocaLisa system with the conventional mapping/ablation approach for radiofrequency ablation of AFL. Methods and Results: Fifty consecutive patients with AFL (39 men and 11 women; age 65 +/- 10 years) were studied. The patients were randomly assigned to undergo radiofrequency ablation guided by a conventional fluoroscopy-based approach (24 patients) or by the LocaLisa system (26 patients). Ablation success rate and documentation of bidirectional isthmus block were 100% in both groups. Compared with fluoroscopy-guided approaches, LocaLisa-guided procedures demonstrated a reduction in total fluoroscopy time from 15.9 +/- 10.6 minutes to 7.5 +/- 6.5 minutes (P < 0.005). Total fluoroscopy dosage was reduced from 21.0 +/- 19.8 to 8.7 +/- 9.5 Gycm(2) (P < 0.05). Fluoroscopy time required for ablation was significantly shortened in the LocaLisa group (2.6+/- 2.6 min) compared with the conventional approach group (11 +/- 10 min, P < 0.0005). In 9(35 %) of 26 patients, the ablation could be performed with a fluoroscopy time less than or equal to 1 minute. There were no significant differences with regard to the number of radiofrequency applications, fluoroscopy time needed for diagnostic reasons, total procedure time, or other ablation data. Conclusion: Compared with the conventional approach, the LocaLisa system significantly reduces the fluoroscopy times needed for ablation of typical AFL.