Difficult to recruit eligible subjects

This study will assess the outcomes of using magnetic navigation to treat ventricular tachycardia (VT) or premature ventricular contractions (PVCs) that occur for unknown reasons and are not related to structural heart disease.

During conventional ventricular arrhythmia ablation procedures, simply contacting the cardiac wall can significantly alter the electrocardiogram. Induction of ventricular ectopy is important in determining the focus of the arrhythmogenic tissue during an electrophysiology (EP) procedure; however, instrumentation with stiff ablation catheters can temporarily eliminate VT during the mapping portion of the procedure making it difficult to track the arrhythmia prior to ablating the tissue responsible for its genesis. The catheters used with the Stereotaxis Magnetic Navigation System (MNS) are less stiff compared to manual catheters since no pull wires are required to deflect the distal tip. Large external magnets positioned on either side of the EP procedure table create a magnetic field within the patient's chest. These large magnets (in direct relationship to the magnetic field) can be manipulated using specialized software. The physician controls the distal tip of the catheter by using the software while remotely using a catheter advancing system (QuickCAS®, Stereotaxis, Inc, St. Louis, MO) to reach the desired location within the heart. The soft catheters may provide a unique quality to the electrophysiologist who may assist by providing accurate maps without temporarily eliminating the ventricular ectopy due to excessive mechanical forces applied to the cardiac tissue. This study will assess the physician's ability to appropriately map and ablate the ventricular substrate using remote magnetic technology. All devices are approved by FDA and no off-label use of the products is mandated within the protocol.

Inclusion Criteria:

• Patients must be between 18 - 80 years of age
• Willing to provide written informed consent
• Present with ventricular ectopy of non-ischemic origin
• able to be safely exposed to a static magnetic field
• Failure of at least 1 antiarrhythmic medication

Exclusion Criteria:

• Presence of a mobile ventricular thrombus
• Unable to obtain percutaneous access to the left ventricle
• Contraindicated for short-term anticoagulation therapy
• Life expectancy less than 1 year
• Body habitus limits placement on the procedure table
• Previously failed ablation procedure for VT/PVCs

Patients will be diagnosed with any ventricular tachycardia or symptomatic PVCs of non-ischemic origin.