The purpose of this clinical study is to see whether a medical device called the DiamondTemp Ablation Catheter (also called the DiamondTemp Ablation System) can restore the heart to a normal heart rhythm.The DiamondTemp Ablation System being evaluated in this research study is investigational because it is not approved by the FDA for the treatment of atrial fibrillation by radiofrequency ablation. The DiamondTemp System is like systems currently being used to treat atrial fibrillation with radiofrequency ablation including the control system that participants could be randomized to.
This study is being done to see if receiving electrical treatment from a cardiac resynchronization therapy (CRT) device with the AdaptivCRT (aCRT) programming feature is better than receiving electrical treatment from a CRT device with the standard method of CRT device programming in patients with heart failure. Subjects will receive an already approved CRT pacemaker or defibrillator depending on what the doctor recommends. Approximately 3000 subjects will be enrolled at up to 200 centers around the world.