Purpose

BNP is predominantly secreted by the ventricles of the heart in response to increased pressure. BNP acts as a vasodilator and has diuretic and natriuretic properties. BNP suppresses both sympathetic tone and the renin-angiotensin system. These physiologic effects serve to reduce intraventricular pressure and improve the symptoms of congestive heart failure (CHF). BNP levels increase with age and can be transiently increased by vigorous exercise. BNP levels have been shown to be useful in the diagnosis of patients with symptoms that are consistent with CHF. BNP levels can be used to accurately identify patients with CHF from a population of patients presenting at the emergency room with shortness of breath. A BNP value >80 pg / mL could be used to identify patients with CHF from this population with a sensitivity of 97% and specificity of 98%.