Natriuretic peptides in assessment of left-ventricular dysfunction

Abstract

The heart secrets two different natriuretic peptides, atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), which have potent vasorelaxant, diuretic, and natriuretic actions. They are main tools in the body's defense against volume overload and hypertension. The natriuretic peptides (NP) are synthetized as prohormones. The C-terminal endocrinological active peptides and their N-terminal prohormone fragments are found in plasma. The NP system is maximally activated in ventricular dysfunction. However, NP:s are also increased in patients with renal failure or pulmonary hypertension, and increases may be found in arterial hypertension or liver cirrhosis. Among all NP and prohormone fragments currently BNP is the most promising candidate analyte for routine diagnosis. BNP is also superior to other neurohormones for diagnosis of left-ventricular dysfunction (LVD) or estimating prognosis in LVD or during the subacute phase of myocardial infarction. For primary care physicians BNP measurement is useful to decide which patient with suspected heart failure warrants further investigation, particularly when assessment of left ventricular function is not readily available. BNP has an excellent negative predictive value particularly in high risk patients. For the cardiologists the NP:s are helpful for monitoring therapy and disease course in LVD patients and for estimating prognosis in LVD and myocardial infarction patients. There is now sufficient evidence to encourage physicians to gain experience with NP as a supplement in the diagnosis of patients suspected of having heart failure. An increase in BNP is serious enough to warrant follow-up examinations.