Final answer:
BNP is elevated in heart failure patients due to excessive stretching of ventricular cells. It helps to lower blood volume and pressure by increasing sodium and water excretion from the kidneys, useful in diagnosing and managing HF.
Step-by-step explanation:
The BNP (B-type natriuretic peptide) is typically elevated in patients with heart failure (HF). BNP is secreted by cells in the ventricles of the heart in response to excessive stretching caused by increased blood volume. This can occur as a result of heart failure, where the heart cannot pump blood effectively, leading to elevated intracardiac pressure and volume. BNP and ANP (atrial natriuretic peptide) work to lower blood pressure and blood volume by promoting the loss of sodium and water through the kidneys, suppressing renin and aldosterone, and reducing the reabsorption of sodium in the renal tubules. A significant elevation in BNP is often used clinically to diagnose and assess the severity of heart failure, and it can be a helpful marker for prognosis and treatment response.