[Influence of cardiac structure, blood flow velocity and heart function on circulating atrial natriuretic peptide and renin-angiotension system].

Heart function and plasma atrial natriuretic peptide (ANP), plasma renin activity (PRA) and angiotension II (Ang II) were examined with echocardiography and radioimmunoassay in 9 patients with dilated cardiomyopathy (DCM), 41 with rheumatic heart disease (RHD), 29 with hyperthyroidism (Ht) and 24 normal subjects. ANP level was significantly increased as heart failure progressed (P < 0.01 and 0.001). There was negative correlation between ANP and left ventricular fractional shortening, and between ANP and ejection fraction in DCM and Ht groups. There was positive correlation between ANP and maximal left atrial diameter, right atrial area, and diastolic diameter or volume of left ventricle in DCM and RHD groups, and negative correlation between ANP and peak flow velocity in aorta or through mitral valve in DCM group (r = -0.608, P < 0.05 and r = 0.710, P < 0.05). These findings suggest that the stronger the myocardial contractility and the faster the blood flow, the lower the plasma ANP level.