Brain natriuretic peptide (BNP), forms together with atrial natriuretic peptide (ANP) a peptide family involved in the regulation of blood pressure and fluid volume. It is used for the early diagnosis of heart failure (HF) in patients presenting to the emergency room with dyspnea. Additionally, in patients with chronic HF and acute and chronic coronary syndrome, BNP is a marker of unfavorable prognosis, being associated with increased mortality.