Cardiac secretion of atrial and brain natriuretic peptides in acute ischaemic heart failure in pigs: effect of angiotensin II receptor antagonism.

In a model of acute ischaemic left ventricular failure in pigs, we compared the plasma levels and cardiac secretion of the three atrial peptides, atrial natriuretic factor (ANF), N-terminal proatrial natriuretic factor (N-terminal proANF) and brain natriuretic peptide (BNP). Acute ischaemic left ventricular failure was induced by embolization of the left coronary artery with plastic microspheres. Thereafter, treatment was given by an intravenous injection of the angiotensin II receptor (AT1) antagonist losartan. Effects of failure induction and treatment were documented by measurement of haemodynamic parameters and plasma concentrations of catecholamines, plasma renin activity, angiotensin II and aldosterone. Acute left ventricular failure was accompanied by significant increases in cardiac secretion and plasma levels of all three atrial peptides, which was considerably more pronounced for ANF and N-terminal proANF than for BNP. Treatment with losartan resulted in significant decreases in plasma ANF and N-terminal proANF, whereas BNP did not change. These findings indicate that ANF and N-terminal proANF may be better suited than BNP as markers of cardiac preload during the development and treatment of acute heart failure.