Resync-AF (Rate vs Rhythm Control in AF Patients With CRT-D)

This study is being done to find out if controlling rate or controlling rhythm is better for heart failure patients who also have AF. Patients with AF who are receiving a CRT-D device and AV node ablation as part of their clinical care will be followed for one year. One group will have their heart rate controlled by the ICD and AVN ablation alone and the second group will be treated with the ICD, AVN ablation and standard medical therapies to restore the heart's normal rhythm. The study doctors will compare the information collected from all of the subjects in this study to see if treating rate or treating rhythm is better in patients with heart failure and AF, resulting in a better quality of life.