EFFECTS OF LONG-TERM INFUSION OF SYNTHETIC ATRIAL-NATRIURETIC-FACTOR ON HEMODYNAMICS AND WATER INPUT-OUTPUT BALANCE IN PATIENTS WITH ACUTE MYOCARDIAL-INFARCTION

The administration of atrial natriuretic factor (ANF) increases corona ry blood flow and decreases coronary vascular resistance. However, lit tle is known about the feasibility and reliability of intravenous long -term infusion of ANF in patients with coronary heart disease. We ther efore examined the effects on hemodynamic parameters and water input-o utput balance of 24-hour administration of synthetic ANF (ANF-[99-126] : 20-50 ng/kg/min) in 8 patients with acute myocardial infarction (6 m en and 2 women; mean age 55 years). The ANF infusion significantly dec reased pulmonary capillary wedge pressure to a maximum of greater than 50% 4 hours after infusion (from 16+/-2 to 7+/-2 mmHg; p<0.01), and t he effect was sustained throughout the 24-hour infusion without diures is (mean water balance, +25+/-12 ml/hr). This reduction was significan tly correlated with the baseline value before infusion (r=-0.85, p<0.0 1). The effect on pulmonary capillary wedge pressure was accompanied b y small reductions (approximately 20%) in systemic blood pressure and cardiac index, without significant changes in systemic vascular resist ance and heart rate. These results indicate that prolonged administrat ion of low to medium doses of synthetic ANF causes potent and sustaine d left ventricular unloading without reflex tachycardia and volume dep letion, and may thus be safe and have potential benefits for patients with coronary heart disease.