Quantifying Congestion by Ultrasound

The investigators will determine the feasibility of identifying and quantifying changes in interstitial and intravascular congestion by imaging in participants with heart failure. The investigators will either continue or temporarily suspend both loop diuretics and mineralo-corticoid antagonists (MRA) for 48 hours in participants with heart failure that is both stable and mild and compare measurements of interstitial (B-lines) and intra-vascular fluids (IVC and JV diameter and renal venous flow) by ultrasound and, in a subset of participants without contra-indications, by cardiac MRI.