Renal, hormonal, and hemodynamic effects of low-dose infusion of atrial natriuretic factor in acute myocardial infarction.

The effects of low-dose infusion of atrial natriuretic factor (ANF; 3 pmol/kg/min; i.e., 10 ng/kg/min) were investigated in a single-blind, random-order, placebo-controlled study of 12 patients with uncomplicated acute myocardial infarction (MI). Compared with the placebo, ANF induced an increase in urine volume (p less than 0.05), sodium excretion (p less than 0.05), and chloride excretion (p less than 0.05). Urinary potassium and creatinine clearance were unchanged. The maximal response of urinary sodium excretion rate after ANF infusion was positively correlated with the basal sodium excretion rate (r = 0.579; p less than 0.05) and inversely correlated with basal plasma renin activity (r = -0.623; p less than 0.05). Furthermore, the plasma aldosterone concentration (PAC) after infusion of ANF was significantly decreased compared with the basal level. The maximal change in PAC was closely correlated with the basal PAC (r = -0.857; p less than 0.01). However, no significant effect on hemodynamic variables was detected with infusion of ANF. Although additional studies are needed to assess the clinical efficacy of ANF infusion in acute MI, our observations suggest that low-dose infusion of the peptide is potentially valuable, as either sole or adjunctive therapy, for the management of water-sodium retention in acute MI.