There are three forms of brain natriuretic peptide in myocardial cells: proBNP, BNP, and N-terminal proBNP. BNP is a peptide composed of 32 amino acids and a circular structure composed of 17 amino acids. It is a short peptide hormone secreted by the heart. The 134 amino acid pre pro BNP synthesized in myocardial cells is degraded into a BNP precursor (proBNP) containing 108 amino acids after entering the bloodstream. Under the action of endonucleases, proBNP forms a biologically active BNP and an inactive 76 amino acid fragment NT proBNP. BNP is a biologically active protein with a half-life of 20 minutes. Its in vitro stability time is only 1 hour, and its level is easily affected by the selected drug. When patients receive recombinant human brain BNP (rh-BNP) for treatment, it can lead to an increase in BNP levels in the blood. It is difficult for clinical doctors to determine whether the increase in BNP levels is caused by medication or heart dysfunction. As an inactive NT-proBNP, it has a half-life of 60-120 minutes and a stability time of up to 24 hours in vitro. It has higher sensitivity and is not affected by rh-BNP, making it easy for clinical doctors to accurately detect early and mild heart failure.