A patient with congestive heart failure (CHF) may exhibit signs and symptoms that are nonspecific; among these are edema, hypertension, shortness of breath, and weakness. Until recently the diagnosis of CHF was difficult, lengthy, and often concluded by ruling out other conditions.
B-type natriuretic peptide (BNP) and/or the N-terminal fragment, NT-proBNP, are now routinely measured to diagnose CHF.
ProBNP is the precursor of BNP. It is released from the left ventricle myocardium in response to mechanical stretch. This stretch is described as an increase in ventricular wall tension because of pressure and volume overload that occurs in CHF. ProBNP is then enzymatically cleaved to produce BNP and NT-ProBNP. BNP is the active hormone composed of 32 amino acids. The N-terminal fragment is a larger chain of 76 amino acids; this fragment is inactive. Studies indicate that NT-proBNP has the same clinical utility as BNP.
Besides diagnosing CHF, the levels of BNP and NT-ProBNP correlate to the severity of the heart disease, assist in detection of CHF where patients are asymptomatic, and differentiate patients whose pulmonary disease presents with symptoms similar to CHF.
