CardioInsight 2 - Non-responder

Background Cardiac Resynchronization Therapy (CRT) is proven to improve survival and heart function of patient with certain electrical conduction abnormality and heart failure. However, in patient with certain electrical conduction abnormality, being nonresponder is observed in up to 40% in patient receiving CRT. Conventionally the surgical approach of CRT is to implant one pacing lead in the right heart and one in the left heart to resynchronize the contraction and the pacing lead in the left heart is usually placed in the posterior or lateral portion of the left heart. However, this single approach may not be optimal, especially for those patients with conduction abnormality known to have no response to CRT. Purpose of the clinical investigation. The purpose of the Electrical Activation Guided CRT for Nonresponders Study is to study the effectiveness of an addition of Hisbundle pacing approach to CRT nonresponder by direct His-bundle pacing to improve the responder rate of nonresponder of conventional CRT and a tailored made approach to CRT procedure by using a noninvasive globally mapping system studying the electrical conduction under different approaches to delivery CRT. The pacing approach that optimally corrects conduction abnormality will be determined before the actual addition of new lead procedure. Conduct of the Investigation This study will include 18 patients already implanted with device delivering conventional CRT that known to have no response to the conventional CRT after 6 months of the CRT therapy from Prince of Wales Hospital, Hong Kong. You will be followed in the device clinic as per usual care after your participation in the study is completed.