NPPB and hydrops fetalis: These have a high negative predictive value for HF and congestion as causes of dyspnea (Ponikowski et al., 2016), with thresholds for ruling out AHF of Brain Natriuretic Peptide (BNP) < 100 pg/ml and N-terminal prohormone of BNP (NT-proBNP) < 300 ng/ml, which may vary according to sex, ejection fraction, and the presence of atrial fibrillation.