HEMODYNAMIC EFFECTS OF α-HUMAN ATRIAL NATRIURETIC POLYPEPTIDE ON PATIENTS UNDERGOING OPEN-HEART SURGERY

A cardiac hormone, α-human atrial natriuretic polypeptide (α-hANP), acts as a vasodilator and a diuretic by activating cyclic GMP. The purpose of this study is to evaluate hemodynamic effects of continuous intravenous infusion of α-hANP on patients undergoing open-heart surgery. A total of 10 patients, including six patients with CABG, two with AVR, one with CABG plus AVR, and one with AVR plus MVR, had intravenous administration of α-hANP on postoperative day 1 with a dose of 0.05μg/kg/min. The mean age of the patients was 69 years, ranging 64 to 77. The plasma concentration of α-hANP increased sufficiently after beginning of contiunous intravenous infusion without any adverse side effects, and also the urine volume increased. The administration of α-hANP induced a significant decrease in central venous pressure, and decreasing tendencies in pulmonary capillary wedged pressure and pulmonary vascular resistance index. Systemic vascular resistance index and cardiac output remained unchanged. Since the administration of α-hANP decreases preload and facilitates adequate urination, it is useful for the management of patients associated with volume overload following open-heart surgery. In this study, it was obscure that α-hANP increased cardiac output by decreasing afterload and by intensifying the contractile force of the heart.