What are the other Names for this Test? (Equivalent Terms)
- Brain Natriuretic Peptide Blood Test
- B-Type Brain Natriuretic Peptide Blood Test
- N-Terminal Pro Brain Natriuretic Peptide Blood Test
What is BNP and NT-proBNP Blood Test? (Background Information)
- Brain Natriuretic Peptide (BNP) is a hormone that reduces blood volume and pressure. It is produced by the walls of the heart in response to an increase in blood volume and pressure
- Contrary to its name, BNP is made by the heart, not the brain. The heart contains 4 chambers: the right and left atria, and the right and left ventricles
- When the level of blood entering the heart increases, heart muscle cells stretch. This stimulates the release of BNP by the ventricles and a similar hormone, ANP (atrial natriuretic peptide) by the atria
- BNP is effectively a “mayday” hormone. Cells in the heart walls secrete BNP to inform the rest of the body that the heart is experiencing a rising influx of blood. BNP then travels through the blood stream to reach target organs to exert its effects
- At the kidneys, BNP increases salt and water excretion; at the hypothalamus of the brain, BNP reduces thirst; and at the blood vessels, BNP causes dilation. These effects combine to reduce blood volume and pressure, which alleviates stresses on the walls of the heart
- BNP also inhibits the release of hormones that increase blood volume and pressure, such as vassopressin, aldosterone, and adrenaline. This ensures that two opposing mechanisms are acting at the same time
- The heart walls produce BNP directly, only when they stretch. However, they also produce a BNP precursor, proBNP, continuously in small amounts. Enzymes cut proBNP into active BNP and N-terminal proBNP (NP-proBNP)
- BNP and NT-proBNP levels elevate, when the walls of the heart stretch. This can occur normally, such as when exercising, or in pathologic conditions, such as a heart failure
- The BNP and NT-proBNP Blood Test is a test that is used to assess the levels of BNP and NT-proBNP in blood. It is used to detect a recent heart failure. A heart failure results, when blood backs up due to the heart’s inability to properly pump blood
What are the Clinical Indications for performing the BNP and NT-proBNP Blood Test?
Following are the clinical indications for performing a BNP and NT-proBNP Blood Test:
- Monitoring the effects of therapy for heart failure
- Shortness of breath
- Swollen extremities, particularly feet and ankles
- Heart abnormalities
- Loss of appetite
- Frequent urination
- Swollen veins
- Enlarged liver and enlarged spleen
How is the Specimen Collected for BNP and NT-proBNP Blood Test?
Following is the specimen collection process for BNP and NT-proBNP Blood Test:
Sample required: Blood
Process: Insertion of a needle into an arm vein.
Preparation required: No special preparation is needed prior to the test.
What is the Significance of the BNP and NT-proBNP Blood Test Result?
Elevated levels of BNP and NT-proBNP may indicate heart failure. This can be due to:
- Chronically high blood pressure
- Coronary artery disease
The laboratory test results are NOT to be interpreted as results of a "stand-alone" test. The test results have to be interpreted after correlating with suitable clinical findings and additional supplemental tests/information. Your healthcare providers will explain the meaning of your tests results, based on the overall clinical scenario.
Additional and Relevant Useful Information:
- Levels of BNP and proBNP increase with age
- Heart disease, along with diabetes, is the leading cause of death and disability in many countries, including in the United States
Certain medications that you may be currently taking may influence the outcome of the test. Hence, it is important to inform your healthcare provider, the complete list of medications (including any herbal supplements) you are currently taking. This will help the healthcare provider interpret your test results more accurately and avoid unnecessary chances of a misdiagnosis.