NPPB and hydrops fetalis: The natriuretic peptide family is a sensitive marker of cardiac volume load and pressure load, and family members include B-type natriuretic peptide (BNP) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) is the most commonly used indicator to assess the prognosis of HF and has been used in HFpEF risk prediction models.