Evaluation of Left Bundle Branch Area Pacing As A Rescue Strategy for Cardiac Resynchronization Therapy Non-Response

Inclusion Criteria: All Veterans in this study will have undergone CRT at least 12 months prior to enrollment and determined to have non-response by all the following criteria: * Lack of improvement in New York Heart Association (NYHA) class * Lack of LVEF increase by \> 5% * Lack of decrease in LVESV by \> 15% Exclusion Criteria: * Unable to understand or provide informed consent * Unable or unwilling to participate in the protocol or comply with any of its components * Pregnant women * Known cancer patients, actively receiving chemotherapy * Patients unable to pass MRI safety screening (intra-orbital metallic foreign bodies, severe claustrophobia, etc) * Patients with anatomical difficulties for implanting LBBAP * Patients with high risk of procedure-related infection * Immunocompromised patients