Procedure protocol improved - study protocol became obsolete

Magnetic navigation will permit delivery of the LV lead tip to a prospectively defined location more efficiently and in a higher proportion of patients than is possible with manual navigation.

MAGNET CRT is designed to compare magnetic navigation to manual (i.e., traditional) navigation in placing an over-the-wire (OTW)left ventricle (LV) lead at a target site identified by the investigator. This is a prospective, randomized, multicenter trial in which randomization (2:1, magnetic: manual navigation) will occur after the patient-specific target site is identified on two hardcopy x-ray images of the coronary venogram. The target area will be identified upon review of a venogram of the patient's coronary venous system taken during the current procedure.

Other variables such as navigating through the vasculature to a potential target site (especially if the path is tortuous), achieving good contact with the myocardium, providing repositioning if needed, countering heart motion, retrograde blood flow, and maintaining a stable delivery system during the release of the lead, are all determinants in the success of LV lead placement.

The Magnetic Navigation System (MNS) may thus aid in coronary venous vasculature navigation of guidewires for over-the-wire (OTW) left ventricular (LV) pacing lead placement by assisting in directing the tip of the guidewire, regardless of the tortuosity of a given patient's anatomy.

No investigational products will be used in the conduct of this study. The Niobe® Magnetic Navigation System and all Stereotaxis guidewires and other disposable products to be utilized have received US marketing clearance, and the protocol applications are within their specified intended use.

Inclusion Criteria/Exclusion Criteria:

1. The patient is 18 years of age or older.
2. The patient is clinically indicated for left ventricular lead placement as part of a pacing or defibrillator system.
3. The patient may be safely exposed to magnetic fields that exist in Niobe® MNS laboratory.
4. The patient is not participating in any clinical trial or studies that would conflict with the guidewire navigation/LV lead implant protocol for this study.
5. The patient is not pregnant, and if of childbearing potential has completed a pregnancy test which resulted negative.
6. The patient does not have an implanted pacemaker or defibrillator, unless such device will be explanted or otherwise deactivated during this procedure.
7. The patient has no contraindications for contrast dye injection.
8. The patient's diastolic blood pressure is greater than 40 mm Hg.
9. In the opinion of the investigator, the patient's general health status does not preclude participation in the study.
10. In the opinion of the investigator, the patient is a reasonable candidate for participation in this study.
11. The patient is not expected to undergo a heart transplant in the next 6 months.
12. The patient does not have a mechanical triscupid heart valve.
13. The patient has not had a myocardial infarction, unstable angina, percutaneous coronary intervention, or coronary artery bypass graft during the preceding 30 days prior to enrollment.