Stereotaxis Study To Obliterate Persistent Ventricular Tachycardia

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.

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