Infants with an unbalanced atrioventricular septal defect (AVSD) frequently present with comorbidities that may have an impact on their medical course and outcome. This study aimed to assess outcomes and explore possible prognostic indicators for patients undergoing surgical palliation for an unbalanced AVSD. The medical records of all infants presenting to the authors' institution with an unbalanced AVSD over a 5-year period were retrospectively reviewed for assessment of outcomes and comorbidities. The study group consisted of 44 patients with an overall survival rate of 51% for the entire follow-up period. The majority of these patients (88%) underwent single-ventricle palliation, with an 83% rate of survival to initial hospital discharge and an overall long-term survival rate of 50%. The midterm outcome was significantly worse than that for a cohort of hypoplastic left heart syndrome patients undergoing single-ventricle palliation during the same period (P = 0.03). In addition, 30% of the patients required either repair or replacement of their systemic atrioventricular valve at initial palliation or during subsequent follow-up evaluation. Of the patients with an unbalanced AVSD, 75% had associated congenital anomalies. In conclusion, infants with an unbalanced AVSD are a high-risk population with diminished midterm survival compared with palliated patients who have more classic forms of hypoplastic heart syndromes. This may be due to the higher incidence of both severe atrioventricular valve regurgitation and important associated congenital anomalies.

Giant right atrial aneurysm is a rare form of congenital heart disease with a wide spectrum of clinical presentation varying from asymptomatic patients to those with refractory atrial arrhythmias or severe airway obstruction. Diagnosis is often confused with other causes of right atrial dilation such as Ebstein disease. Because of its rare occurrence and variable clinical presentation, inconsistencies in medical and surgical management strategies exist between centers. We present five cases of giant right atrial aneurysm managed at our institution and discuss the clinical presentation, diagnostic challenges, and medical and surgical management.

In infants with congenital heart disease who are placed on venoarterial extracorporeal membrane oxygenation postoperatively, hyperoxia (defined as a mean PaO2 > 193 mm Hg in the first 48 hr of extracorporeal membrane oxygenation) was an independent risk factor for 30-day mortality after surgery. Future studies are needed to delineate the causative or associative role of hyperoxia with outcomes, especially in children with baseline cyanosis who may be more susceptible to the effects of oxidative stress.