EFFECTS OF EXERCISE ON PLASMA-LEVEL OF BRAIN NATRIURETIC PEPTIDE IN CONGESTIVE-HEART-FAILURE WITH AND WITHOUT LEFT-VENTRICULAR DYSFUNCTION

This study was designed to determine whether plasma brain natriuretic peptide (BNP) increases in response to exercise in patients with conge stive heart failure and to show what kind of hemodynamic abnormalities induce increased secretion of BNP during exercise. Plasma levels of a trial natriuretic peptide (ANP) and BNP and hemodynamic parameters wer e measured during upright bicycle exercise tests in seven patients wit h dilated cardiomyopathy and nine with mitral stenosis. At rest, there were no intergroup differences in cardiac output or pulmonary capilla ry wedge pressure; however, the group with dilated cardiomyopathy had higher left ventricular end-diastolic pressures and lower left ventric ular ejection fractions than did the group with mitral stenosis. Plasm a ANP levels were comparable between the dilated cardiomyopathy group (170 +/- 77 [SE] pg/ml) and the mitral stenosis group (106 +/- 33 pg/m l) (p, not significant), whereas BNP was significantly higher in the d ilated cardiomyopathy group (221 +/- 80 pg/ml) than in the other group (37 +/- 10 pg/ml) (p < 0.05). The plasma concentration of BNP but not of ANP significantly correlated with left ventricular end-diastolic p ressure and volume. Exercise increased plasma ANP and BNP in the two g roups. The dilated cardiomyopathy group had a larger increment in BNP (+157 +/- 79 pg/ml) than did the mitral stenosis group (+17 +/- 5 pg/m l) (p < 0.05), although the increase in pulmonary capillary wedge pres sure was greater in the mitral stenosis group. Thus exercise increases plasma levels of BNP, and impaired left ventricular function may be a main factor in the greater increment in BNP during exercise in patien ts with congestive heart failure.