Quartet Lead and Resynchronization Therapy Options III (QUARTO_III)

Inclusion Criteria: * Patient that will be implanted with a Cardiac Resynchronization Therapy (CRT-D) with the MultiPoint Pacing (MPP) feature under the current Guidelines indications for CRT-D implant (including upgrades from single or dual chamber Defibrillator or Pacemaker). * Patient that will be implanted with a Quartet Left Ventricular (LV) quadripolar lead. * In sinus rhythm at baseline visit. * Patients with Left Bundle Branch Block (LBBB) * Must be willing and able to comply with study requirements. * Older than 18 years * Must indicate their understanding of the study and willingness to participate by signing an appropriate informed consent form. Exclusion Criteria: * Already has a CRT device implanted. * Myocardial Infarction or unstable angina within 40 days prior the enrollment. * New York Heart Association (NYHA) Class IV * Recent cardiac revascularization in the 4 weeks prior to enrollment. * Cerebrovascular Accident (CVA) or Transient Ischemic Attack (TIA) in the 3 months prior the enrollment. * Classification of Status 1 for cardiac transplantation or consideration for transplantation over the next 12 months. * Primary valvular disease requiring surgical intervention. * Atrial Fibrillation (AF): * Persistent AF at the time of enrollment or 30 days prior the enrollment * Permanent AF not treated with Atrio-Ventricular node ablation within 2 weeks after the CRT-D implant * History or incidence of Paroxysmal or Persistent AF within 30 days prior the en…