The purpose of this non-randomized, cross-over, unblinded, single-center feasibility study is to assess the sensitivity of the LINQ ICM to measure derived-subcutaneous impedance in patients with heart failure during periods when diuretics and/or HF-medication consumption is increased or suspended for 48 hours (up to 72 hours at physician discretion) and to collect safety information related to HF status and to medication consumption changes.