According to guidelines, single determination of B-type Natriuretic peptide (BNP) should be used for distinguishing between cardiac and non-cardiac acute dyspnea at the emergency room. BNP measurement is also recommended before hospital discharge in patients hospitalized for heart failure to assess prognosis and to evaluate treatment efficacy.In acute cardiogenic pulmonary edema, BNP is measured using a single BNP determination, but the temporal behavior of BNP during pulmonary edema recovery is unknown.