A medical device system for monitoring a patient's heart includes an implantable medical device (IMD) configured to determine sensing vector data for multiple sensing vectors selected from electrodes coupled to the IMD. The system further includes an external device configured to receive the sensing vector data and provide at least a portion of the sensing vector data to a user display configured to display sensing vector criteria and the sensing vector data as part of a graphical user interface for programming a sensing vector used by the implantable medical device for monitoring a patient's heart rhythm.