Marinobufagenin, an endogenous ligand of alpha-1 sodium pump, is a marker of congestive heart failure severity.

Background: A reduced cardiac output in chronic heart failure (CHF) evokes renal NaCl and water retention, and, therefore, activates mechanisms promoting natriuresis. Atrial natriuretic peptide (ANP) is one such factor. We hypothesized that another NaCl sensitive endogenous natriuretic factor, i.