One of the more helpful tests that I’ve used recently in the past few years or so is the B-natriuretic peptide (BNP). It recently came up in a story I was reading.
I was reminded of how useful the test was during a recent emergency room shift. In those presenting with shortness of breath, one has to decide whether the cause is the lungs (pneumonia, COPD, asthma) or the heart (CHF). There are not infrequent cases where patients have both lung and heart disease and a physician has to know what is causing the symptoms in order to guide treatment.
From a NEJM study, a plasma BNP >100 pg/mL diagnosed HF with a sensitivity, specificity, and predictive accuracy of 90, 76, and 83 percent, respectively. Together with clinical suspicion and other supportive tests (i.e. chest X-ray), this is certainly a nice tool to have when evaluating shortness of breath.
