OBJECTIVETo determine the correlation between the serum level of B-natriuretic peptide (BNP) and hemodynamic variables and to evaluate the diagnostic value of BNP in patients with decompensated heart failure (HF).

METHODSBNP levels (TRIAGE BIOSITE Diagnostics, San Diego, USA) were obtained by a rapid immunofluorescence assay in 117 patients with dyspnea including cardiogenic group (75 patients) and lung disease (42 patients). Hemodynamic parameters of 53 patients [male 28, female 25, mean age (71.6 +/- 9.8) years] with HF were determined and left ventricular end-diastolic diameter (LVEDD) of all patients were measured by echocardiogram.

RESULTSPulmonary capillary wedge pressure (PCWP, mm Hg), mean pulmonary arterial pressure (MPAP, mm Hg), right atrial pressure (RAP, mm Hg) and BNP (ng/L) levels according to New York Heart Association (NYHA) class were: 16.10 +/- 3.50, 22.50 +/- 4.68, 3.11 +/- 1.90, 271.25 +/- 159.29 in NYHA class II, respectively; 21.50 +/- 4.42, 28.60 +/- 9.35, 8.95 +/- 3.86, 619.58 +/- 237.48 in NYHA class III; 29.28 +/- 8.61, 36.50 +/- 12.32, 15.27 +/- 4.96, 1519.28 +/- 618.62 in NYHA class IV (P < 0.01-0.05), respectively. PCWP, MPAP, RAP and plasma BNP levels were directly proportional to cardiac function. The plasma BNP levels had also significant positive correlations with PCWP, MPAP, RAP, (r = 0.59, 0.50, 0.32, P < 0.05-0.01). BNP level [(918.48 +/- 453.25) ng/L] of the group with LVEDD (n = 24) > or = 60 mm was much higher than that of the group with LVEDD (n = 29) < 60 mm [(298.58 +/- 167.51) ng/L]. However, the latter was significantly higher than that in pulmonary dyspnea group with a normal left and right ventricular end-diastolic diameter [(35.4 +/- 26.4) ng/L, P < 0.01]. There was a great difference of BNP between cardiogenic dyspnea group [(761.30 +/- 480.47) ng/L]and lung dyspnea group [(35.4 +/- 26.4) ng/L], P < 0.01.

CONCLUSIONSThe plasma BNP levels had significant positive correlations with PCWP, MPAP, RAP. BNP is a cardiac neurohormone secreted from cardiac ventricles as a response to ventricular volume expansion and pressure overload. Rapid testing BNP should be of help to differentiate pulmonary dyspnea from cardiac etiologies.