title: Plasma L-arginine and metabolites of nitric oxide synthase in patients with left-to-right shunt after intracardiac repair.
abstract: OBJECTIVE
  Human plasma L-arginine serves as a substrate pool for endothelial-derived nitric oxide (NO) synthase. In this pilot study, we tested the hypothesis that plasma L-arginine and other metabolites of the L-arginine NO pathway could correlate with postoperative pulmonary hypertension after cardiopulmonary bypass (CPB).
  
  
  METHODS
  Forty-two patients (median age, 0.5 years; range, 0.1 to 28 years) with atrial septal defect (n = 15), ventricular septal defect (n = 18), atrioventricular canal (n = 8), and aortopulmonary window (n = 1) were enrolled. The influence of patient age, preoperative pulmonary hypertension, duration of CPB, plasma L-arginine, guanosine 3', 5'-cyclic monophosphate (cGMP), and nitrate on postoperative pulmonary hypertension during the first 24 h after CPB was studied by logistic regression.
  
  
  RESULTS
  Nineteen of 42 patients were found to have preoperative pulmonary hypertension. Thirteen of 42 patients showed persistent pulmonary hypertension after intracardiac repair with a mean pulmonary artery pressure (PAP) of 38 mm Hg (range, 23 to 55 mm Hg) at 24 h after CPB. L-arginine concentrations in plasma were significantly lower 24 h after CPB than before: 52 mumol/L (range, 18 to 95 mumol/L) vs 79 mumol/L (range, 31 to 157 mumol/L). Plasma cGMP levels were higher and plasma nitrate levels were lower immediately after weaning from CPB (p < 0.0033). On logistic regression analysis, only patient age (p = 0.02) and preoperative PAP (p = 0.01) were related to postoperative pulmonary hypertension.
  
  
  CONCLUSIONS
  Low plasma L-arginine does not relate to persistent pulmonary hypertension in patients with left-to-right shunt after CPB and intracardiac repair.
authors.affiliation: Department of Pediatric Cardiology, University Medical Center, INF 153, D-69120 Heidelberg, Germany. Matthias_Gorenflo@med.uni-heidelberg.de
authors.forename: Matthias
authors.initials: M
authors.lastname: Gorenflo
authors.forename: Michael V
authors.initials: MV
authors.lastname: Ullmann
authors.forename: Katharina
authors.initials: K
authors.lastname: Eitel
authors.forename: Jasmin
authors.initials: J
authors.lastname: Gross
authors.forename: Walter
authors.initials: W
authors.lastname: Fiehn
authors.forename: Siegfried
authors.initials: S
authors.lastname: Hagl
authors.forename: Jens
authors.initials: J
authors.lastname: Dreyhaupt
mesh_terms: D000293:Adolescent; D000328:Adult; D001120:Arginine / Q000097:blood*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D006152:Cyclic GMP / Q000097:blood; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D006976:Hypertension, Pulmonary / Q000097:blood / Q000209:etiology / Q000378:metabolism*; D007223:Infant; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism*
chemical_list: D001120:Arginine; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP