NPPB and heart failure: As in adult patients, the brain natriuretic peptide (BNP)/N-terminal prohormone BNP is used as a biomarker heart failure in childhood, despite the knowledge that there is an age-dependent variation in normal individuals from ~3000 pg/ml in 0–2 days of age, which drops to ~100 pg/ml between 1 month and 1-year of age (Nir et al., 2009; Schmaltz, 2015).