Natriuretic peptides are hormones produced within the heart and released into the circulation in response to stretch. Both atrial natriuretic peptide (ANP) and brain-type natriuretic peptide (BNP) relate to left ventricular filling pressure. High levels of both, and of the inactive fragment, N-terminal proANP, are associated with poor long-term prognosis in congestive heart failure and survival after acute myocardial infarction.
Correlations were recently found between plasma N-terminal proANP levels and parameters of systolic and diastolic dysfunction. The parameters of left ventricular filling pressures are the early/atrial (late) filling phase ratio (E/A ratio), and the E and A wave velocities and deceleration times. Doppler-derived diastolic filling variables can predict cardiac mortality in dilated cardiomyopathy and congestive heart failure. Fruhwald et al reported that functional impairment in idiopathic dilated cardiomyopathy correlates with the diastolic Doppler filling pattern. A restrictive filling pattern on transmitral Doppler echocardiography was more often associated with high New York Heart Association (NYHA) class than abnormal relaxation. In left ventricular systolic dysfunction, restrictive filling was associated with higher functional class. In another study, Fruhwald et al showed a relationship between natriuretic peptides and diastolic Doppler parameters of left ventricular filling in dilated cardiomyopathy. Restrictive diastolic filling was associated with marked elevation of both N-terminal proANP and BNP, hence with a poor prognosis.
biochemistry; ventricular diastolic dysfunction; natriuretic peptide; neurohumoral activation; left ventricular filling pressure; prognosis