NPPB and hydrops fetalis: According to these guidelines, the diagnosis of HFmrEF includes four elements: HF symptoms with or without signs, LVEF in the range of 40–49%, elevated brain natriuretic peptide (BNP) concentration (>35 pg/ml) or N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration (>125 pg/ml), and relevant structural heart disease or diastolic dysfunction (11).