Reduction or Extension of COnduction Time With Ventricular Electromechanical Remodeling (RECOVER)

Inclusion Criteria: * meeting the current ESC or ACCF/AHA/HRS Class I or Class IIa indications for cardiac-resynchronization (CRT) implant Exclusion Criteria: * Myocardial infarction, unstable angina within 40 days prior the enrollment * Recent cardiac revascularization in the 4 weeks prior to the enrollment or planned for the 3 months following * Cerebrovascular accident (CVA) or transient ischemic attack (TIA) in the 3 months prior to the enrollment * Primary valvular disease requiring surgical correction * Pregnant or are planning during the duration of the investigation * Status 1 candidate for cardiac transplantation or consideration for transplantation over the next 12 months * Post-cardiac transplantation * Life expectancy \< 12 months * Currently participating in any other clinical investigation except for observational registry