HOUSTON, TEXAS. The Stereotaxis Niobe system is a magnetically-guided, remotely-controlled system for performing radiofrequency (RF) ablation. It is usually combined with the CartoMerge system and a CT scan to provide accurate mapping and precise catheter location. The main advantages of the system are the substantially improved mapping accuracy, greater flexibility of the catheter enabling its tip to reach areas in the left atrium which may be difficult to reach with a manually-guided catheter, and the fact that the catheter movement can be controlled remotely, thus substantially reducing radiation exposure to the operator. It is expected that the use of the Stereotaxis system will significantly improve the outcome of RF ablations, even if carried out by relatively inexperienced electrophysiologists.

EPs at the Ohio State University Medical Center and the University of Texas now report on the case of a 72-year-old man experiencing daily episodes of atrial tachycardia causing palpitations and shortness of breath. The patients underwent a RF ablation using the Stereotaxis system with a 4-mm tip Navistar-RMT catheter. The operators located the source of the tachycardia and isolated it with 5 lesions (burns). The total procedure time was close to 5 hours (275 minutes) with a fluoroscopy time of 29 minutes. After the ablation it was no longer possible to induce the tachycardia. The authors of the report conclude that, �From our experience in general, and this case in particular (where the entire mapping and ablation procedure was performed safely, effectively, and efficiently with remote navigation), we feel that Stereotaxis Niobe MNS potentially has wide applicability in the area of interventional ablation therapy of complex cardiac arrhythmias.�

Mehta, R, et al. Successful ablation of focal left atrial tachycardia using Stereotaxis Niobe remote magnetic navigation system. Europace, Vol. 10, 2008, pp. 280-83

Editor�s comment: Although one large study undertaken at the Cleveland Clinic found significant shortcomings with the Stereotaxis system when used in pulmonary vein isolation, it is expected that these shortcomings (inadequate lesion depth and charring at catheter tip) have been overcome through the development of an irrigated catheter. Other studies have confirmed the advantages of the system in achieving immediate success in eliminating arrhythmias, but a definitive study of the long-term success rate of the system for PVI is still awaited.