Hemodynamic effects of alpha-human atrial natriuretic polypeptide on patients undergoing open-heart surgery

Background A cardiac hormone, alpha-human atrial natriuretic polypeptide (a lpha-hANP), acts as a vasodilator and a diuretic by activating cyclic GMP f ormation. We studied the hemodynamic effects of continuous intravenous infu sion of alpha-hANP on patients undergoing open-heart surgery. Methods, A total of 15 patients, including 7 with CABG, 4 with AVR, 2 with CABG plus AVR, and 2 with AVR plus MVR were involved in the study. They und erwent open-heart surgery in our institute between July 1996 and April 1997 , The mean age of patients was 68 years, ranging from 63 to 77, A dosage of 0.05 mu g/kg/min of alpha-hANP was administered to all patients on postope rative day 1, Hemodynamics and blood and urine samples were measured at the following times: 2 hours before continuous intravenous infusion of alpha-h ANP, 0, 1, 2, 3, 6, 12 and 24 hours after continuous intravenous infusion. We concomitantly measured urine volume and the plasma concentration of alph a-hANP. Results, The plasma concentration of alpha-hANP increased sufficiently afte r the beginning of continuous intravenous infusion without any side effects , and the urine volume increased too, The administration of alpha-hANP indu ced a decrease in central venous pressure, pulmonary capillary wedged press ure and the pulmonary vascular resistance index, Systemic vascular resistan ce index and cardiac output remained unchanged Conclusions. It is useful for the management of patients with associated vo lume overload following open-heart surgery because the administration of al pha-hANP decreases preload and facilitates satisfactory urination.