Neurodevelopmental impairments are the most common extracardiac morbidities among patients with complex congenital heart disease (CHD) across the lifespan. Robust clinical research in this area has revealed several cardiac, medical, and social factors that can contribute to neurodevelopmental outcome in the context of CHD. Studies using brain magnetic resonance imaging (MRI) have been instrumental in identifying quantitative and qualitative difference in brain structure and maturation in this patient population. Full-term newborns with complex CHD are known to have abnormal microstructural and metabolic brain development with patterns similar to those seen in premature infants at approximately 34 to 36 weeks' gestation. With the advent of fetal brain MRI, these brain abnormalities are now documented as they begin in utero, as early as the third trimester. Importantly, disturbed brain development in utero is now known to be independently associated with neurodevelopmental outcome in early childhood, making the prenatal period an important timeframe for potential interventions. Advances in fetal brain MRI provide a robust imaging tool to use in future neuroprotective clinical trials. The causes of abnormal fetal brain development are multifactorial and include cardiovascular physiology, genetic abnormalities, placental impairment, and other environmental and social factors. This review provides an overview of current knowledge of brain development in the context of CHD, common prenatal imaging tools to evaluate the developing fetal brain in CHD, and known risk factors contributing to brain immaturity.

Objective

Recurrence risk of congenital heart disease (CHD) in families with an affected first-degree relative is increased as compared with the general population. Advances in genetic testing and evidence that preconceptual folic acid supplementation may decrease risk of CHD warrant preventative counseling for at-risk families. Our goal was to document patterns of preconceptual folic acid supplementation and recurrence risk counseling in at-risk families in order to identify opportunities for improved preventative care.

Design

Mothers referred for a fetal echocardiogram were prospectively enrolled. Cases were defined as mothers deemed to be at higher risk of having an affected fetus with CHD given an affected parent or affected previous pregnancy with CHD. Controls were defined as mothers with no prenatal risk factors. Mothers completed a validated questionnaire assessing use of folic acid supplementation and receipt of recurrence risk counseling. Chi-square analyses were performed to analyze questionnaire responses and demographic data.

Results

A total of 314 subjects participated (controls = 216, cases = 98). Cases took preconceptual folic acid supplementation more often than controls (P < .001), but only 55% started preconceptually. Maternal advanced education and counseling (P < .001) were associated with preconceptual supplementation, whereas complexity of CHD in the relative was not. While 70% of cases received some recurrence risk counseling, those with advanced education and complex CHD in the affected relative were more likely to receive counseling. Few at-risk cases interacted with genetic services (19%).

Conclusions

At-risk mothers with lower education are less likely to take preconceptual folic acid supplementation or receive recurrence risk counseling. Health care providers should proactively provide this information to all at-risk patients and develop collaborations with genetic services.

Background Tube-assisted feeding in infancy is common in patients with single-ventricle physiology ( SVP ). Postnatal brain development is delayed, and injury is common, in patients with SVP . The role of brain findings in feeding outcomes remains unclear. We sought to determine the association between neonatal perioperative brain injury and postnatal brain maturation with feeding-tube dependency in patients with SVP at neonatal discharge and just before the stage-2 palliation. Methods and Results We evaluated a cohort of 48 term neonates with SVP who underwent pre- and postoperative brain magnetic resonance imaging. Perioperative brain injury and microstructural brain development were measured with diffusion tensor imaging including fractional anisotropy in white matter and apparent diffusion coefficient in gray matter. The primary outcome was defined as being 100% orally fed (binary). Of the patients 79% (38/48) were tube fed at hospital discharge, and 27% (12/45) were tube fed before stage-2 palliation. Perioperative brain injury did not differ by group. Orally fed patients had a faster rate of decrease in apparent diffusion coefficient (3%, 95% CI 1.7% to 4.6%, P<0.001) at discharge and a faster rate of increase in fractional anisotropy (1.4%, 95% CI 0.6% to 2.2%, P=0.001) at the time of stage-2 palliation compared with tube-fed patients, denoting more robust brain development. Conclusions Slower rate of postnatal brain maturation but not perioperative brain injury is associated with feeding modality in infancy. These results support the importance of brain health in optimizing feeding outcomes in patients with SVP .

BACKGROUND: T2-weighted Single Shot Fast Spin Echo (SSFSE) scans at 3 Tesla (3T) are increasingly used to image fetal pathology due to their excellent tissue contrast resolution and signal-to-noise ratio (SNR). Temperature changes that may occur in response to radio frequency (RF) pulses used for these sequences at 3T have not been studied in human fetal brains. To evaluate the safety of T2-weighted SSFSE for fetal brains at 3T, magnetic resonance (MR) thermometry was used to measure relative temperature changes in a typical clinical fetal brain MR exam. METHODS: Relative temperature was estimated using sets of gradient recalled echo (GRE) images acquired before and after T2-weighted SSFSE images which lasted 27.47±8.19 minutes. Thirty-one fetuses with cardiac abnormalities, and 20 healthy controls were included in this study. Fetal brain temperature was estimated by proton resonance frequency (PRF) thermometry and compared to the estimated temperature in the gluteal muscle of the mother. Seven scans with excessive motion were excluded. Local outlier factor (LOF) was performed to remove 12 additional scans with spurious phase measurements due to motion degradation and potential field drift. Linear regression was performed to determine if temperature changes are dependent on the rate of energy deposition during the scan. RESULTS: For the 32 participants used in the analysis, 17 with cardiac abnormalities and 15 healthy controls, the average relative fetal temperate change was 0.19±0.73 ℃ higher than the mother, with no correlation between relative temperature change and the rate of images acquired during the scans (regression coefficient =-0.05, R-squared =0.05, P=0.22, F-statistic =1.60). The difference in the relative temperature changes between the fetal brain and mothers gluteal tissue in the healthy controls was on average 0.08 ℃ lower and found not to be statistically different (P=0.76) to the group with cardiac abnormalities. CONCLUSIONS: Our results indicate that the estimated relative temperature changes of the fetal brain compared to the mothers gluteal tissue from RF pulses during the course of the T2-weighted SSFSE fetal MR exam are minimal. The differences in acquired phase between these regions through the exam were found not to be statistically different. These findings support that fetal brain imaging at 3T is within FDA limits and safe.

Current recurrence risk counseling for conotruncal cardiac defects (CTD) is based on empiric estimates from multiple studies. We examined the risk of congenital heart disease (CHD) in relatives of probands with CTDs to assist in counseling practices in the current era. One thousand six-twenty probands with CTDs and no reported chromosomal or genetic abnormalities were recruited sequentially. A three-generation pedigree was obtained for each proband by a genetic counselor detailing the presence and type of CHD in each family member. Risks and 95% confidence intervals (CI) were calculated for sub-groups of relatives based on degree of relationship for all probands and by individual lesion of the proband. For pairs of affected relatives, concordance rates were calculated. Severity of CHD in the affected relative was assessed. The risk of CHD was higher in siblings (4.4%, 95% CI 3.4-5.4) than in parents (1.5%, 95% CI 1.1-1.9). Risk varied by the cardiac lesion of the proband with the highest risk in first-degree relatives of probands with tetralogy of Fallot and the lowest in D-transposition of the great arteries. 39% of affected parents and 69% of affected siblings had a concordant lesion (i.e., CTD). Most affected siblings of probands with severe CTDs had complex defects (58%), whereas very few affected parents had complex defects (20%). These data suggest that recurrence risk varies by lesion and relationship, with substantial concordance observed by cardiac lesion and complexity of disease, particularly among siblings. These findings contribute to risk counseling in the current era.

• A PAVM was diagnosed in a critically ill cyanotic neonate. • Echocardiography played a pivotal role in establishing the diagnosis. • Urgent transcatheter device occlusion resulted in immediate hemodynamic stabilization.

Background

Characterization of brain injury and neurodevelopmental (ND) outcomes in critical congenital heart disease (cCHD) has primarily focused on hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA). This study reports brain injury and ND outcomes among patients with heterogeneous cCHD diagnoses beyond HLHS and TGA.

Methods

This prospective cohort study included infants with HLHS, TGA, or heterogenous "Other cCHD" including left- or right-sided obstructive lesions, anomalous pulmonary venous return, and truncus arteriosus. Brain injury on perioperative brain MRI and ND outcomes on the Bayley-II at 30 months were compared.

Results

A total of 218 participants were included (HLHS = 60; TGA = 118; "Other cCHD" = 40, including 8 with genetic syndromes). Pre-operative (n = 209) and post-operative (n = 189) MRI showed similarly high brain injury rates across groups, regardless of cardiopulmonary bypass exposure. At 30 months, participants with "Other cCHD" had lower cognitive scores (p = 0.035) compared to those with HLHS and TGA, though worse ND outcome in this group was driven by those with genetic disorders.

Conclusions

Frequency of brain injury and neurodevelopmental delay among patients with "Other cCHD" is similar to those with HLHS or TGA. Patients with all cCHD lesions are at risk for impaired outcomes; developmental and genetic screening is indicated.

Impact

This study adds to literature on risk of brain injury in patients with critical congenital heart disease (cCHD) diagnoses other than hypoplastic left heart syndrome (HLHS) and transposition of the great arteries (TGA), a heterogenous cohort of patients that has often been excluded from imaging studies. Children with cCHD beyond HLHS and TGA have similarly high rates of acquired brain injury. The high rate of neurodevelopmental impairment in this heterogenous group of cCHD diagnoses beyond HLHS and TGA is primarily driven by patients with comorbid genetic syndromes such as 22q11.2 deletion syndrome.

Background

A growing body of evidence indicates that right ventricular dysfunction in patients with palliated hypoplastic left heart syndrome (HLHS) originates in fetal life. In this study, the systolic-to-diastolic time index (SDI) was used to study the presence of ventricular dysfunction in single right ventricles in fetuses with HLHS or evolving HLHS and to assess whether this dysfunction is related to increase preload, myocardial performance, or interventricular interaction.

Methods

Echocardiograms from 78 fetuses with HLHS and 10 with evolving HLHS were retrospectively compared with those of 78 normal control fetuses. Fetuses with HLHS were further grouped according to morphology of the left ventricle (LV): not visible (n = 35) or visible (n = 43). Spectral Doppler signals obtained from right ventricular inflow (blood pool) and tissue Doppler from the tricuspid lateral annulus were analyzed. The SDI was calculated as the ratio of the ejection time plus isovolumic contraction and relaxation times to the diastolic filling time. E/A and E/e' ratios, cardiac output, preload index, and Tei index were also calculated.

Results

Fetuses with HLHS demonstrated significantly elevated right ventricular SDI values by both blood pool Doppler and Doppler tissue imaging compared with control subjects (1.89 ± 0.33 vs 1.58 ± 0.29 [P < .001] and 2.1 ± 0.57 vs 1.66 ± 0.31 [P < .001], respectively). Changes in filling time rather than ejection time predominated. Fetuses with HLHS with visible LVs and those with evolving HLHS had significantly higher SDI values than fetuses with HLHS without visible LVs (no visible LV, 1.75 ± 0.22; visible LV, 2 ± 0.36; P = .001; evolving HLHS, 2.19 ± 0.68; P < .001). SDI was correlated with the Tei index (R = 0.58) and was more sensitive than the Tei index in identifying differences between the HLHS subgroups.

Conclusions

Fetuses with evolving and overt HLHS exhibit abnormally increased SDI values in utero. This difference is likely related to inherently pathologic interventricular interactions and/or diastolic dysfunction of the right ventricle in fetuses with HLHS.