BNP natriuretic peptide measurement is used as an adjunctive test to diagnose congestive heart failure.
More information
Natriuretic peptides are structurally similar peptides produced by whole-body cells. Two of them, A-type natriuretic peptide (ANP - Atrial Natriuretic Peptide) and B-type natriuretic peptide (BNP - Brain Natriuretic Peptide), are produced by myocardial cells. ANP is made exclusively by the muscle cells of the heart's ventricles, while BNP is produced by the muscle cells of both the atria and ventricles of the heart. The natriuretic peptides ANP and BNP maintain homeostasis by promoting diuresis and sodium excretion (natriuresis). BNP is released from the ventricles, especially the left ventricle, during increased pressure or oncotic overload. It causes dilation of arteries and veins and also reduces the levels of vasoconstrictor hormones and sodium-retaining neurohormones. It is now known that ventricular overload leads to the release of both BNP and N-terminal (amino-terminal) proBNP (NT-proBNP).
Although ANP was the first natriuretic peptide, BNP is the most widely used clinically. This is partly due to its longer half-life (20 minutes for BNP vs. 3 minutes for ANP), and exercise does not affect BNP levels. In contrast, ANP levels can be affected by regular physical activity. NT-proBNP has a half-life of 120 minutes, making it somewhat less helpful for monitoring acute changes. However, it is used in the diagnosis of heart failure, and several studies suggest it is a strong predictor of mortality.
The use of BNP in helping to diagnose heart failure is well established. BNP levels are elevated in patients with symptomatic heart failure in a decompensated state. However, patients with left ventricular dysfunction compensated by medical therapy may have normal BNP levels. Measuring BNP is particularly useful in distinguishing between dyspnea due to heart failure and other causes. BNP levels may increase in women and the elderly while obesity may appear (falsely) decreased.
Possible Interpretations of Pathological Values
- Increase: Acute lung injury, acute myocardial infarction, chronic renal failure, cirrhosis, congestive heart failure, coronary angioplasty, hypertension, hypervolemic states, left ventricular hypertrophy, pulmonary hypertension.
- Decrease: Therapeutic response to antihypertensive therapy, therapeutic response to diuretic therapy.
Important Note
Laboratory test results are crucial for diagnosing and monitoring all pathological conditions. 70% and 80% of diagnostic decisions are based on laboratory tests. Correct interpretation of laboratory results allows a doctor to distinguish "healthy" from "diseased."
Laboratory test results should not be interpreted from the numerical result of a single analysis. Test results should be analyzed based on each case and family history, clinical findings, and the results of other laboratory tests and information. Your physician should explain the importance of your test results.
At Diagnostiki Athinon, we answer any questions you may have about the test you perform in our laboratory and contact your doctor to ensure you receive the best possible medical care.
