Integrated Diagnostic for Heart Failure

Inclusion Criteria: * Patient is 18 years of age or older * Patient ( or patient's legally authorized representative) is willing and able to provide written informed consent * Patient is willing and able to comply with the required study follow up visits * Patient is implanted with a Medtronic wireless ICD or CRT-D device capable of OptiVol fluid monitoring feature * Patient is on Medtronic CareLink network or is willing to be enrolled on the CareLink network * Patient is being managed, or has been managed, by a HF clinician * Patient has signed an informed consent for CareLink Network Services * Patient is implanted with device for at least three months * Patient is willing and able to transmit data using the CareLink home monitor (2490C). Exclusion Criteria: * Patient is participating in another study that may interfere with TRIAGE-HF protocol required procedures * Patient with an implantable cardiac device that is indicated to reach ERI in less than 12 months