Dextro-Transposition of Great Arteries and Neurodevelopmental Outcomes: A Review of the Literature

Prenatal Detection of D-TGA and Novel Interventional Program Decrease Time to Balloon Septostomy

Infants with dextro-transposition of the great arteries (d-TGA) are at high risk for hemodynamic compromise in the immediate postnatal period due to dependence on intracardiac mixing for oxygen delivery. This period of profound hypoxemia may have long-term implications, as previous studies demonstrated patients with d-TGA are at increased risk for neurocognitive delays despite effective surgical correction in the neonatal period. Balloon atrial septostomy (BAS) is an established intervention that improves intracardiac mixing and perioperative hemodynamics. This retrospective study aimed to quantify the time from birth to BAS and compare short-term outcomes for patients with prenatal and postnatal diagnoses of d-TGA. We identified 68 newborns born with d-TGA who were admitted to our facility between 2013 and 2022 and required BAS within 48 h after birth. Halfway through this study, our cardiac interventional team began traveling to a nearby delivery center where a bedside BAS could be performed prior to transferring the patient. We divided the patients into 3 groups-postnatal diagnosis (n = 27), prenatal diagnosis with rapid transport (n = 24), and prenatal diagnosis with interventional team performing a BAS at the delivery hospital (n = 17). The time from birth to BAS was significantly shorter for patients in the interventional program group (1.1 h) compared to the rapid transport (4.5 h) and postnatal diagnosis groups (9.3 h, p value < 0.01). The interventional program group also had lower lactate levels and less acidotic pH compared to the other groups. There was no significant difference in lowest oxygen saturation level, pre-surgical neurologic complication rate, time to surgery, or hospital length of stay. The interventional program proved to be a safe and effective model, as there were no procedural complications and the time to BAS decreased. Long-term follow-up is needed to determine if abating this initial period of hemodynamic instability will lead to improved neurodevelopmental outcomes.

A case report of spastic diplegic cerebral palsy in a late preterm child with hypoplastic left heart syndrome

Background

Congenital heart disease (CHD) is the most common birth defect, affecting 1% of children who are born in the United States each year. Children with hypoplastic left heart syndrome, a type of critical CHD, are at high risk for neurodevelopmental disabilities, which are conditions that can affect motor, language, and cognitive development. In children with critical CHD, the severity and prevalence of their motor delays is most pronounced in infancy.

Case Description

We present a case of a former late preterm male with hypoplastic left heart syndrome and history of hypoxic ischemic encephalopathy, who was diagnosed with spastic diplegic cerebral palsy in the setting of periventricular leukomalacia. Like many children with critical CHD, this child had gross motor delays and tone abnormalities in infancy. However, unlike many children with CHD, he continued to have neurologic differences that prompted additional evaluation through a Cardiac Neurodevelopmental Program. He was diagnosed with spastic diplegic cerebral palsy based upon clinical history and physical examination. Ancillary testing showed periventricular leukomalacia on brain magnetic resonance imaging (MRI); this finding was consistent with his clinical diagnosis.

Conclusions

This is an interesting case report of spastic diplegic cerebral palsy in a late preterm infant with critical CHD. When making a diagnosis of cerebral palsy, it is important to consider the etiology of the motor impairment. Selective vulnerability may have played a factor in this child's condition. The most vulnerable part of the neonatal brain is the periventricular white matter; cerebral hypoxia can lead to periventricular leukomalacia. Children with CHD have brain dysmaturity beginning in-utero. Thus, it is possible that this child's brain dysmaturity may have increased his susceptibility to periventricular leukomalacia. Because most children with CHD have gross motor delays in infancy, it may be challenging to make a definitive diagnosis of cerebral palsy in an infant with critical CHD. Children with cerebral palsy have early motor delays that persist throughout life. It is the identification of persistent motor impairments through repeat evaluations that enabled this child's cerebral palsy diagnosis. This illustrates the importance of developmental surveillance in children with critical CHD.

The Genetics of Neurodevelopment in Congenital Heart Disease

Congenital heart disease (CHD) is the most common birth anomaly, affecting almost 1% of infants. Neurodevelopmental delay is the most common extracardiac feature in people with CHD. Many factors may contribute to neurodevelopmental risk, including genetic factors, CHD physiology, and the prenatal/postnatal environment. Damaging variants are most highly enriched among individuals with extracardiac anomalies or neurodevelopmental delay in addition to CHD, indicating that genetic factors have an impact beyond cardiac tissues in people with CHD. Potential sources of genetic risk include large deletions or duplications that affect multiple genes, such as 22q11 deletion syndrome, single genes that alter both heart and brain development, such as CHD7, and common variants that affect neurodevelopmental resiliency, such as APOE. Increased use of genome-sequencing technologies in studies of neurodevelopmental outcomes in people with CHD will improve our ability to detect relevant genes and variants. Ultimately, such knowledge can lead to improved and more timely intervention of learning support for affected children.