ADRB3 and hydrops fetalis: This dual-sided paradigm would largely explain the discrepancies reported on the protective or deleterious effects of β3-AR stimulation in the diseased heart, depending on the phenotypic stage and/or HF model (myocardial infarction, hemodynamic pressure overload, ischemia-reperfusion, etc.), disease severity and timing in the progression of pathological remodeling.