What is B-Type Natriuretic Peptide?

B-type natriuretic peptide (BNP) is a chain of 32 amino acids that make up a polypeptide. The word poly means many, so the term polypeptide means many peptides. Amino acids are present throughout the body and are the building blocks of polypeptides and proteins. A high level of b-type natriuretic peptide in the blood can be an indicator of a serious problem with the heart.

If an individual is having a problem breathing or is experiencing swelling in the legs, the doctor may order a BNP test. This blood test measures the amount of b-type natriuretic peptide in the blood. If the BNP level is high this can tell the doctor the heart is not functioning properly.

Too much pressure in the heart will cause high levels of BNP in the blood. Pressure in the heart occurs when the lower two chambers of the heart are not pumping as effectively as they could be. These lower chambers of the heart are called the ventricles. When these ventricles fail it can cause a condition called congestive heart failure.

When an individual has congestive heart failure, the pressure causes the heart muscles to expand or stretch. When these muscles are stretched, b-type natriuretic peptide is released into the blood. The higher the level of BNP in the blood, the more severe the heart failure. The severity of heart failure determines how aggressive the treatment should be.

It is easy to test for the presence of b-type natriuretic peptide in the blood. A small amount of blood will be drawn from the vein using a needle. This blood is placed in a laboratory machine that can test for BNP. The results should be determined in approximately 15 minutes. Almost every hospital in the United States has the ability to run this BNP test.

There are few risks involved with this type of test. Some people may experience bruising at the needle insertion site. For those who have a bleeding disorder, prolonged bleeding may be a problem. In rare cases, infection can occur at the puncture site. In most cases, there are no adverse effects from testing the blood for b-type natriuretic peptide.

Because symptoms of heart failure can mimic symptoms of other conditions, the BNP test is an important diagnostic tool. A recent study proved that the BNP blood test accurately detected heart failure 83 percent of the time. This is a valuable lab test for emergency room doctors to use in clinical decision making processes. Sometimes quick action is needed to treat an individual in severe congestive heart failure.