Cardiac resynchronization therapy (CRT) is a major breakthrough in therapy for patients with advanced congestive heart failure, however, a number of key clinical research questions remain, perhaps most importantly the issue of why apparently suitable patients do not respond to CRT. These issues are also relevant to patients who do respond to CRT as potentially their response might be further increased. Though patients do not respond to CRT because of many known postulated reasons, we review the importance of maintaining atrioventricular intrinsic conduction during CRT in this paper, which maybe is one of methods to reduce the rates of non-response to CRT.