BOSTON, Jan. 29 A test for BNP, or B-type natriuretic peptide, is a simple, safe blood test that can help doctors evaluate cardiac function, says a U.S. study.BNP belongs to a family of protein hormones called natriuretic peptides, which includes ANP, BNP, CNP and DNP. Natriuretic peptides are part of the body's natural defense mechanisms designed to protect the heart from stress and play an important role in regulating circulation. They promote urine excretion, relax blood vessels, lower blood pressure and reduce the heart's workload, according to the February issue of Harvard Men's Health Watch.Measurement of BNP helps doctors diagnose and treat congestive heart failure. In this condition, the heart is unable to pump blood efficiently, and the heart chambers swell with blood. As the heart cells stretch, they produce extra BNP, which pours into the bloodstream.By measuring blood levels of BNP, doctors can spot signs of congestive heart failure in its early stages, when it may be hard to distinguish from other disorders. A normal BNP level is about 98 percent accurate in ruling out heart failure. In general, the higher the level, the worse the heart failure.Copyright 2007 by UPI
