Initial Experience With Remote Catheter Ablation Using a Novel Magnetic Navigation System

Background— Catheters are typically stiff and incorporate a pull-wire mechanism to allow tip deflection. While standing at the patient’s side, the operator manually navigates the catheter in the heart using fluoroscopic guidance. Methods and Results— A total of 42 patients (32 female; mean age, 55±15 years) underwent ablation of common-type (slow/fast) or uncommon-type (slow/slow) atrioventricular nodal reentrant tachycardia (AVNRT) with the use of the magnetic navigation system Niobe (Stereotaxis, Inc). It consists of 2 computer-controlled permanent magnets located on opposite sides of the patient, which create a steerable external magnetic field (0.08 T). A small magnet embedded in the catheter tip causes the catheter to align and to be steered by the external magnetic field. A motor drive advances or retracts the catheter, enabling complete remote navigation. Radiofrequency current was applied with the use of a remote-controlled 4-mm, solid-tip, magnetic navigation–enabled catheter (55°C, maximum 40 W, 60 seconds) in all patients. The investigators, who were situated in the control room, performed the ablation using a mean of 7.2±4.7 radiofrequency current applications (mean fluoroscopy time, 8.9±6.2 minutes; procedure duration, 145±43 minutes). Slow pathway ablation was achieved in 15 patients, whereas slow pathway modulation was the end point in the remaining patients. There were no complications. Conclusions— The Niobe magnetic navigation system is a new platform technology allowing remote-controlled navigation of an ablation catheter. In conjunction with a motor drive unit, this system was used successfully to perform completely remote-controlled mapping and ablation in patients with AVNRT.