EFFECTS OF BRAIN NATRIURETIC PEPTIDE ON EXERCISE HEMODYNAMICS AND NEUROHORMONES IN ISOLATED DIASTOLIC HEART-FAILURE

Background Experimental models suggest that brain natriuretic peptide (BNP) can modify left ventricular diastolic performance. The aim of th is study was to evaluate the effects of BNP on resting and exercise he modynamics and neurohormones in patients with isolated diastolic heart failure. Methods and Results Six patients with isolated diastolic hea rt failure were studied. After baseline hemodynamic measurements were obtained with use of thermistor-tipped pulmonary artery catheters, pat ients were randomized to receive infusion of BNP or placebo in a singl e-blind, crossover study. Hemodynamic and neurohormonal parameters wer e measured at rest after 30 minutes of infusion and during incremental supine bicycle exercise. BNP did not significantly affect resting hem odynamics but attenuated the rise in both pulmonary capillary wedge pr essure (placebo, 23+/-2 mm Hg; BNP, 16+/-2 mm Hg; P<.01) and mean pulm onary artery pressure (placebo, 34+/-3 mm Hg; BNP, 29+/-3 mm Hg; P<.05 ) during exercise without affecting changes in heart rate, systemic bl ood pressure, or stroke volume. In response to BNP, there was signific ant suppression of plasma aldosterone concentration (placebo, 551+/-10 7 pmol/L; BNP, 381+/-56 pmol/L; P<.05). Conclusions BNP infusion cause s beneficial hemodynamic and neurohormonal effects during exercise in patients with isolated diastolic heart failure.