Stereotaxis Study To Obliterate Persistent Ventricular Tachycardia (STOP-VT)

Stereotaxis Study To Obliterate Persistent Ventricular Tachycardia: Data Collection of Clinical Scar-related VT Cases

This is a prospective, non-randomized, multi-center clinical case series evaluating the outcomes of the magnetic navigation system in ventricular tachycardia (VT) cases. Subjects will be evaluated acutely and will be followed clinically at 1, 6 and 12 months post-treatment.

Catheter ablation of ventricular tachycardia (VT) is greatly facilitated by using a substrate mapping approach - that is, mapping of the left ventricle during sinus or paced rhythm to identify diseased myocardium. Using three dimensional electroanatomical mapping, it is possible to reconstruct an anatomical rendering of the left ventricle based on voltage. For hemodynamically stable or unstable VTs, various electrophysiologic maneuvers can then be used to identify the critical portions of the VT circuit within the scar (entrainment mapping, identification of diastolic potentials, identification of electrically-unexcitable scar, fractionated potentials and pace mapping). These methods are limited by the resolution of the substrate map, accuracy of catheter manipulation, and operator skill. To this end, a magnetic navigation system has been developed that allows for remote cardiac mapping. When used in concert with a compatible electroanatomical mapping system, it is possible to create a high-density ventricular substrate map of healed myocardial infarction. By removing the necessity for technical skill with catheter manipulation, this system has the potential for both improving the efficacy of VT ablation and expanding the clinical use of this substrate mapping approach. Recently, a higher-powered, irrigated tip catheter has become available in certain markets for use in cardiac arrhythmia ablations. This study will evaluate the outcomes of using this magnetic irrigation ablation catheter during mapping and ablation of VT while also using remote magnetic navigation.

Patients with documented VT and prior MI, in whom an ICD was implanted either for primary or secondary prevention, were recruited for endocardial mapping/ablation during VT (entrainment mapping, activation mapping) and/or substrate mapping in sinus rhythm (elimination of fractionated/late potentials, endocardial scar homogenization) with remote magnetic navigation (Niobe, Stereotaxis Inc.,St Louis, USA) and irrigated RF ablation (NaviStar RMT ThermoCool, Biosense Webster,California, USA).

In order to qualify for inclusion in the chronic success statistic, patients must first be an acute success and must have had no VTs identified in their ICD history post ablation therapy.

Inclusion Criteria: Subject must be between the ages of 18 - 80 years Willing to provide prior written informed consent per local ethics committee guidelines Subjects must present with ventricular tachycardia, characterized by: history of myocardial scar and spontaneous ventricular tachycardia Able to be safely exposed to static magnetic fields No in-situ devices are present or any in-situ devices have been verified to be compatible to magnetic fields Exclusion Criteria: Presence of a mobile ventricular thrombus Inability to access the left ventricle Subjects must not have any contraindications to short-term anticoagulation Subjects must not have a life expectancy of <1 year due to a medical illness