Table 1.

Inclusion and Exclusion Criteria

Inclusion Criteria

Age ≤ 45 days Age > 1 week if born at 35 weeks gestation Single ventricle physiology Stable systemic and pulmonary blood flow Planned superior cavo-pulmonary anastomosis (either the bi-directional Glenn shunt or hemi-Fontan surgery)

Exclusion Criteria

Birth weight ≤ 2.5 kg if gestational age is ≥ 38 weeks; birth weight < the 5th percentile for gestational age if gestational age is 35–37 weeks < 35 weeks gestation Anatomic diagnosis of pulmonary atresia with intact ventricular septum < 3 days after palliative cardiac surgical procedure, if performed Systemic oxygen saturation < 65% Current mechanical ventilatory support Current intravenous inotropic support Creatinine >1.0 mg/dL Absolute neutrophil count <1000 cells/mL Chromosomal or recognizable phenotypic syndrome of non-cardiac congenital abnormalities associated with growth failure (e.g. trisomy 21, Noonan syndrome, Turner syndrome) Prior ACE inhibitor use for > 7 consecutive days Unable to return for follow-up because of distance from clinical site.