[Transposition of the great arteries with pulmonary valvular stenosis and intact interventricular septum. Discussion of management strategies with respect to one case]. / Transposition des gros vaisseaux avec sténose valvulaire pulmonaire à septum interventriculaire intact. Discussion des enjeux thérapeutiques à propos d'un cas.

The authors report the case of a neonate with transposition of the great arteries (TGA) with pulmonary stenosis (PS) and intact Interventricular septum. The child was born at full term without a prenatal diagnosis with cyanosis developing at the 12th hour. After emergency atrioseptostomy, detransposition was performed on the 6th day. Commissurotomy and shaving of the much thickened bicuspid pulmonary valve was also performed. The postoperative course was complicated by a non-compliant left ventricle. After two months, myocardial ischaemia and persistent obstruction of the outflow tract led to severe cardiac failure and the death of the child. TGA with PS and intact interventricular septum is a very rare cardiac malformation. The prognosis is closely related to the anatomy of the pulmonary valve and the impact on the left ventricle. The therapeutic options are complex and are discussed in relation to this case.

Endogenous nitric oxide production and atrial natriuretic peptide biological activity in infants undergoing cardiac operations.

OBJECTIVES: To examine whether preoperative heart failure and cardiac surgery influence nitric oxide production and atrial natriuretic peptide (ANP) biological activity in infants and whether nitric oxide and ANP participate in the control of postoperative pulmonary vascular tone. DESIGN: Prospective, clinical study. SETTING: Tertiary pediatric cardiac intensive care unit in a referral cardiosurgical center. PATIENTS: Nineteen infants (median age 4 months) undergoing cardiac surgery: 13 infants with ventricular or atrioventricular septal defect associated with heart failure and pulmonary hypertension (group 1); and six infants with tetralogy of Fallot, without heart failure (group 2). INTERVENTIONS: Blood samples obtained from indwelling catheters or bypass circuit outlets. MEASUREMENTS AND MAIN RESULTS: Nitrite and nitrate blood concentrations (as a marker for nitric oxide synthesis) and the molar ratio of cyclic guanosine 3',5'-monophosphate (cGMP) to ANP (as a marker for ANP biological activity) were determined before, during, and up to 24 hrs after cardiopulmonary bypass (CPB). In group 1 patients, these biological parameters were related to postoperative pulmonary arterial pressure. Preoperative nitrite and nitrate concentrations were higher in group 1 patients than in group 2 patients (p < .02), and this difference persisted during CPB. Nitrite and nitrate concentrations 24 hrs postoperatively were lower than preoperative values in group 1 patients (p < .05) and were unchanged in group 2 patients. An inverse correlation was observed postoperatively between nitrite and nitrate concentrations and systolic pulmonary arterial pressure (r2 = 0.4, p < .05). Group 1 patients had a lower preoperative cGMP/ANP ratio than group 2 patients (p < .05), despite higher ANP levels (p < .005). The cGMP/ANP ratio decreased during CPB in both groups (p < .0001), and in group 2 patients, cGMP and ANP values remained below preoperative values < or = 24 hrs postoperatively. A correlation was observed between ANP levels and systolic pulmonary arterial pressure 2 and 4 hrs postoperatively (r2 = .4, p < .05, respectively), but no correlation was observed between ANP biological activity and postoperative pulmonary arterial pressure. CONCLUSIONS: Infants with heart failure and pulmonary hypertension have increased nitric oxide synthesis and decreased ANP biological activity; both phenomena may be involved in the pathophysiology of this clinical condition. CPB has no detectable effect on nitric oxide production but does decrease ANP biological activity. In patients with preoperative heart failure and pulmonary hypertension, endogenous nitric oxide appears to play a role in the control of postoperative pulmonary vascular tone.

Interleukin-10 release related to cardiopulmonary bypass in infants undergoing cardiac operations.

To evaluate cytokine balance related to cardiopulmonary bypass, we prospectively investigated 11 infants undergoing cardiac operations for congenital heart disease. Proinflammatory cytokines (tumor necrosis factor-alpha and interleukin-8) and the antiinflammatory cytokine interleukin-10 were measured at multiple time points before, during, and after bypass. Tumor necrosis factor-alpha and interleukin-8 values were within normal range before the operation. These values increased significantly during bypass, reaching their peaks after protamine administration (tumor necrosis factor-alpha, 133.6 +/- 124.9 pg/ml; mean +/- standard deviation; p<0.005) and 2 hours after termination of the procedure (interleukin-8, 92.1 +/- 44.1 pg/ml; p < 0.01). Tumor necrosis factor-alpha and interleukin-8 equaled normal prebypass values from the first postoperative day on. Interleukin-10 levels were within normal range before the operation and were already significantly increased 10 minutes after initiation of bypass (interleukin 10, 39.4 +/- 34.3 pg/ml; p<0.05). These levels remained elevated throughout the procedure but returned to normal after protamine administration. A second significant release of interleukin-10 occurred from the early postoperative period on, reaching its peak 24 hours after termination of cardiopulmonary bypass (interleukin-10, 351.6 +/- 304.0 pg/ml; p < 0.01). Interleukin-10 values were normal on the second postoperative day in all patients. Interleukin-10 kinetics showed an inverse pattern compared with tumor necrosis factor-alpha and interleukin-8. This difference suggests an interplay between proinflammatory and antiinflammatory cytokines released during and after cardiopulmonary bypass. Interleukin-10 levels measured 4 and 24 hours after bypass strongly correlated with the degree of hypothermia during bypass (Spearman's correlation coefficient, -0.77 [p < 0.01] and -0.89 [p < 0.0005], respectively); these levels did not correlate with duration of bypass and aortic crossclamping, however. This result suggests that besides immunologically mediated production of interleukin-10, hypothermia itself could modulate interleukin-10 production. In conclusion, this study demonstrates interleukin-10 production, in addition to interleukin-8 and tumor necrosis factor-alpha synthesis, in response to cardiopulmonary bypass in infants. Interleukin-10 could play a protective role by down-regulating proinflammatory cytokine release during and after cardiopulmonary bypass.