RethinQ Study - Evaluating Pacing in Heart Failure Patients

Patients with heart failure have a pumping action of the ventricles in which one ventricle contracts before the other ventricle. This uncoordinated (unsynchronized) pumping is due to a delay in the stimulation of the left ventricle because of its increased size. Pacing both the right and the left side of the heart (or cardiac resynchronization therapy \[CRT\]) has been proven to be effective in the treatment of heart failure (HF). Current market-approved devices combine both pacing (CRT) and shocking (implantable cardioverter defibrillator \[ICD\]) therapy for patients who have severe heart failure and are at risk for developing life-threatening heart rhythms. These devices provide an electrical pacing stimulus to both ventricles and may help the heart contract in a more coordinated way and improve heart failure symptoms. The investigational portion of this trial involves the implantation of a market-approved CRT implantable cardioverter defibrillator (CRT-D) system in patients who do not meet the current criteria for a CRT implant. In order to receive a CRT-D implant today, patients must have heart failure symptoms, have a weakened heart muscle, and have uncoordinated pumping of the heart. To demonstrate this uncoordinated pumping of the heart, a test (electrocardiogram \[ECG\]) is done. It is believed that by using a different test (echocardiogram) to measure whether this uncoordinated pumping is present, more patients will be identified that will benefit from CRT-D therapy. This study will look at whether patients identified by using this echocardiogram test show a benefit from having this CRT-D therapy.