Plasma L-arginine and metabolites of nitric oxide synthase in patients with left-to-right shunt after intracardiac repair.
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.
Gorenflo
Matthias
M
Department of Pediatric Cardiology, University Medical Center, INF 153, D-69120 Heidelberg, Germany. Matthias_Gorenflo@med.uni-heidelberg.de
Ullmann
Michael V
MV
Eitel
Katharina
K
Gross
Jasmin
J
Fiehn
Walter
W
Hagl
Siegfried
S
Dreyhaupt
Jens
J
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*
D001120:Arginine; D019001:Nitric Oxide Synthase; D006152:Cyclic GMP