A method is disclosed that includes selecting an electrode configuration from a plurality of electrode configurations associated with electrodes of an implantable lead, sensing activity of the right ventricle and the left ventricle, determining an interval between sensed activity of the right ventricle and sensed activity of the left ventricle and determining whether the selected electrode configuration is suitable based at least in part on the interval. In one embodiment, an implantable device performs such a method to improve patient response to the CRT therapy, for example, by selecting a different electrode configuration if the current configuration is not suitable. Other exemplary methods, devices, systems, etc., are also disclosed.