To assess the effects of atrial natriuretic factor (ANF) on cardiac function, synthetic human ANF was infused directly into the left main coronary artery of eight patients with congestive heart failure (CHF) and six subjects with normal left ventricular (LV) function (controls) who underwent cardiac catheterization. ANF infusion at the incremental rates of 60, 125, 400, and 800 ng/min induced a dose-related increase in plasma ANF concentrations in the coronary sinus, from 1,223 +/- 590 to 3,923 +/- 1,123 pg/ml in patients with CHF (p less than 0.01) and from 1,041 +/- 605 to 2,710 +/- 1,741 pg/ml in controls (p less than 0.01). Peripheral plasma ANF concentrations (femoral artery) increased from 538 +/- 278 to 752 +/- 262 pg/ml (p less than 0.01) in patients with CHF and from 193 +/- 63 to 401 +/- 147 pg/ml (p less than 0.01) in controls. The increase in peripheral or coronary sinus plasma ANF concentrations did not differ between patients with CHF and controls. At the three lowest ANF infusion rates, cardiac index (CI), systemic vascular resistance (SVR), and LV contractility assessed by peak positive dP/dt remained unchanged both in patients with CHF and in controls. At the highest ANF infusion rate, CI increased from 2.18 +/- 0.53 to 2.54 +/- 0.49 L/min/m2 (p less than 0.01) and SVR decreased from 14.6 +/- 3.6 to 12.8 +/- 4.5 mm Hg.min/L (p less than 0.01) in patients with CHF. There was no associated change in heart rate (HR), mean arterial blood pressure (MAP), cardiac filling pressures, or peak positive dP/dt.(ABSTRACT TRUNCATED AT 250 WORDS)