Health App Data Collection Study

Inclusion Criteria: * Patients are willing to be compliant with daily measurements required 18 years of age or older * Patients who have been implanted with ABT CRT-D devices connected to Merlin.net * Patients who had at least one HF clinical event during past 12 calendar months * Must provide written informed consent prior to the commencement of this clinical feasibility study * Patients are willing to be compliant with daily measurements required Exclusion Criteria: * Pregnant and/or lactating mothers will be excluded from the study or have a plan to be pregnant in the next 12 months * Patients with a life expectancy less than the duration of the study, as per clinician's discretion. * Patients who will not be able to complete the daily survey questions due to inability to read