AlterationsintheNatriureticHormoneSystemRelatedtoCardiopulmonary BypassinInfantswithCongestiveHeartFailure J.M.Costello, 1,2 C.L.Backer, 3 P.A.Checchia, 4 C.Mavroudis, 3 R.G.Seipelt, 3 D.M.Goodman 2 1 Division of Cardiology, Children’s Memorial Hospital, The Feinberg School of Medicine at Northwestern University, 2300 Children’s Plaza, #73, Chicago, IL 60614-3394, USA 2 Division of Critical Care Medicine, Children’s Memorial Hospital, The Feinberg School of Medicine at Northwestern University, 2300 Children’s Plaza, #73, Chicago, IL 60614-3394, USA 3 Division of Cardiovascular Thoracic Surgery, Children’s Memorial Hospital, The Feinberg School of Medicine at Northwestern University, 2300 Children’s Plaza, #21, Chicago, IL 60614-3394, USA 4 Divisions of Critical Care Medicine and Cardiology, St. Louis Children’s Hospital, Washington University School of Medicine, St. Louis, MO 63110, USA Abstract. This study examined changes in the natri- uretic hormone system in five infants with congestive heart failure (CHF) due to intracardiac left-to-right shunting who were exposed to cardiopulmonary by- pass (CPB) during surgical repair. Plasma concen- trations of three hormones [atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and den- droaspis natriuretic peptide (DNP)] and their sec- ondary messenger, guanosine 3¢,5¢-monophosphate (cGMP), were measured, and the biological activity of the system was quantified. At baseline, BNP and DNP concentrations were normal in our patients, a finding that is strikingly different from that of adult CHF patients, whereas ANP concentrations were elevated. Following CPB, ANP concentrations de- creased (median, 175 vs 44 pg/ml; p = 0.043) and BNP concentrations increased (median, 25 vs 66 pg/ ml; p = 0.043), whereas DNP concentrations did not change. Following modified ultrafiltration, BNP concentrations increased (p = 0.043), but other natriuretic peptide concentrations did not change. The calculated biological activity of the natriuretic hormone system decreased following CPB [molar ratio, cGMP / (ANP + BNP + DNP); median, 213 vs 127; p = 0.043)]. Additional studies are needed to expand on these findings and identify patients with other types of congenital heart disease who have perioperative disturbances in the natriuretic hormone system and thus might benefit from pharmacologic intervention. Keywords: Natriuretic hormones — Congenital heart disease — Congestive heart failure — Cardiopulmo- nary bypass The natriuretic hormone system plays an important role in the pathophysiology, diagnosis, treatment, and prognosis of congestive heart failure (CHF) in adults [20, 21]. Although the cardiovascular disturbances in neurohumoral regulation, vascular tone, and fluid balance seen with CHF are similar to those following cardiopulmonary bypass (CPB), little is known about the natriuretic hormone system in children with con- genital heart disease undergoing CPB. This study examined changes in the natriuretic hormone system in infants with congenital heart disease and CHF due to intracardiac left-to-right shunting who were exposed to CPB during surgical repair. We hypothesized that natriuretic hormone concentrations reflect the cardiac pathophysiology of CHF prior to CPB. Furthermore, we hypothesized that CPB, surgical repair, and modified ultrafiltration (MUF) affect hormonal concentrations and decrease biologic activity. Specifically, since MUF following CPB improves hemodynamics and decreases total body water [23], we hypothesized that MUF de- creases natriuretic hormone concentrations. MaterialsandMethods The institutional review board of the Children’s Memorial Hospital approved the study, and written informed consent was obtained from the parent or guardian of each patient prior to enrollment in the study. Correspondence to: D.M. Goodman Pediatr Cardiol 25:347–353, 2004 DOI: 10.1007/s00246-003-0512-5