To precisely deliver appropriate therapy, cardiac resynchronization therapy devices track vast amounts of physiologic information. This information may be useful in monitoring heart failure patients and may provide meaningful insight into physiologic stability of volume status, activity, and cardiac electrophysiology. It is presumed that frequent monitoring of heart failure patients reduces the morbidity of heart failure by providing information early on so that measures can be taken to prevent congestion leading to acute decompensation. Until recently, however, frequent monitoring required face-to-face encounters in an office setting. Acquisition of device-based diagnostic information is now possible with Internet-based information systems. This article reviews the nature of device-based diagnostic information, examines how its clinical use can be justified, and makes suggestions for work flow that can make information from implanted devices useful in a clinical setting.