The Effects of Posture Change and Continuous Positive Airway Pressure on Cardiac Natriuretic Peptides in Congestive Heart Failure

We studied changes in the peripheral plasma levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) in seven patients with congestive heart failure (CHF) during four 1-h protocols during which patients maintained either an upright or a supine posture with or without nasal continuous positive airway pressure therapy (N-CPAP) at a pressure of 10 cm H2O (FIo2=0.21). The mean plasma ANP concentration of patients increased significantly from baseline at the end of 1 h of recumbency (65.9 ± 5.8 to 82.6 ± 8.3 pg/mL (mean ± standard error); p