AVP and hydrops fetalis: In addition, HF is characterized by increased production of endothelin-1 (ET-1) and ADH following baroreceptor activation (7), both of which enhance systemic vasoconstriction and reduce free water clearance; (4) secretion of various factors that play an important role in the deterioration of the cardiac and renal function along with systemic and local inflammation, endothelial dysfunction, anemia, and other metabolic alterations (6, 35).