Abnormal circulating B-type natriuretic peptide concentration 2017-06-10T18:39:37Z Increased plasma levels of circulating natriuretic peptides (NP) have been described in patients with congestive heart failure and are directly proportional to the severity of congestive heart failure as classified by the New York Heart Association criteria. A deviation from the normal circulating concentration of B-type natriuretic peptide (BNP). Abnormal B-type natriuretic peptide level Abnormal circulating proANP concentration