Remote-controlled catheter ablation of accessory pathways: results from the magnetic laboratory

Aims This study evaluates feasibility, safety, and efficacy of magnetic remote-controlled accessory pathway (AP) ablation. Methods and results The novel magnetic navigation system (MNS) (Niobe, Stereotaxis) creates a steerable magnetic field (0.08 T) controlling the distal magnetic tip of an ablation catheter. In conjunction with a catheter advancer system (Cardiodrive, Stereotaxis) remote catheter ablation is enabled. Conventional electrophysiology study identified AP conduction in 59 patients (37 males, 36 + 14 years, 60 APs). First generation 1-magnet tip (1-M) (group I, n ¼ 18), second generation bipolar 3-magnet tip (3-M) (group II, n ¼ 27), and third generation quadripolar 3-magnet tip catheters (3-M quad.) (group III, n ¼ 14) were used for magnetic remote-controlled ablation. Successful AP ablation was achieved in 67% (group I), 85% (group II), and 92% (group III). A significant decrease of median [IQR: Q1–Q3] fluoroscopy time and dosage was observed: 21.2 [12.1–33.8] min, 1110 [395–3234] mGym 2 (group I); 6.5 [4.4–15.4] min, 290 [129–489] mGym 2 (group II), and 4.9 [3.4–8.0] min, 129 [74–270] mGym 2 (group III). Mean procedure time (217+ 67 min; 182+ 68 min, and 172 + 90 min) significantly decreased in group III. Median number [Q1–Q3] of radiofrequency current applications in groups I, II, and III was 4 [2–9], 4 [2–6], and 2 [2–4], respectively. No complications occurred. Conclusion Remote AP ablation is safe and feasible using the novel MNS. Introduction of the 3-magnet quadripolar ablation catheter significantly improved the efficacy of the procedure.