This investigational study will evaluate whether the Cardioblate® Closure™ Device can be used to occlude the Left Atrial Appendage (LAA) and to further understand the study device performance.  Patients may be able to participate in this study if they are already scheduled to have cardiac surgery and their surgeon believes they may be an appropriate candidate for LAA occlusion.

The LAA is a part of the heart that serves as a reservoir (container) for blood flowing in and out of the left ventricle.  As the blood flows in and out of the LAA, sometimes the blood becomes trapped in the area and forms a blood clot (blood that has been converted from a liquid to a solid state), and could potentially increase the chances of having a stroke.  A stroke occurs when a blood clot blocks an artery (a blood vessel that carries blood from the heart to the body) or a blood vessel (a tube through which the blood moves through the body) breaks, interrupting blood flow to an area of the brain.  The sponsor of this study has developed a device (Cardioblate® Closure™ Device) which will occlude (close off) the LAA with a small band, much like a rubber band.  This small band will be placed around the LAA to stop blood from moving in and out of the appendage, thus potentially reducing the formation of blood clots.

Participation in this study will last for three months and will involve a total of four visits.

This study is looking for patients with atrial fibrillation that are scheduled to have an ablation procedure for treatment.  With atrial fibrillation, electrical impluses don't follow a normal pathway through the heart causing the upper chambers of the heart (atria) to beat too fast in a disorganized, irregular way.  Medicine often helps treat AF.  In some cases, however, the most effective treatment is to destroy the tissue that causes the irregular impulses using radiofrequency energy (RF ablation).  RF ablation uses radio waves to create small scars on the heart's surface that interrupt the abnormal electrical signals and restore a normal heart rhythm.  This procedure is often called cardiac ablation.

The purpose of this study is to use Magnetic Resonance Imaging (MRI) to view lesions after the RF ablation procedure.  MRI is a widely used clinical test that uses magnetic fields and radio waves to provide detailed pictures of the body.  The results of the cardiac MRI may provide doctors with information that can be used to help determine the most effective ablation technique for treatment of atrial fibrillation.

Participation in this study will last for about 3 months and will involve two follow-up visits.