Abstract 13697: Direct Effects of C-Type Natriuretic Peptide on Left Ventricular Contractile Performance in Heart Failure: Assessment by Left Ventricular Pressure-Volume Analysis

Background: Emerging evidence supports C-type natriuretic peptide (CNP), a potent endogenous vasodilating and natriuretic peptide as a new therapeutic option for the treatment of HF. Both circulating and cardiac levels of CNP are increased in patients with congestive heart failure (HF), which may alter left ventricular(LV) functional response to CNP and suggest it is released as a cytoprotective mechanism. However, the direct cardiac effects of CNP, independent of the alterations in loading conditions, remain controversial. We test the hypothesis that CNP has a direct positive inotropic effect on LV contractile performance in HF, which is independent of altered heart rate, load or baroreflexes. Methods: We assessed the cardiac effects of CNP (2 μg/kg plus 0.4 μg/kg/min, iv, 20 min) in 11 chronically-instrumented conscious dogs with pacing-induced HF by using pressure (P)-volume (V) analysis. Results: With reflexes intact, CNP administration significantly reduced LV end-systolic pressure (PES, 94±20 vs 106...