Congenital heart disease (CHD) is a common cause of childhood morbidity, occurring in 6–8/1000 live births, with up to 50% of these children requiring open-heart surgery to correct their defect.1 2 Most forms of CHD can now be definitively repaired with neonatal surgery resulting in good cardiac function. However, neurological deficits are common, particularly in infants. Given the burden of neurodevelopmental impairment following neonatal cardiac surgery, this article will discuss:

• the timing of brain injury in newborns with CHD;

• how the pattern of brain abnormalities on imaging studies, such as stroke or white matter injury, informs etiology;

• the surprising predominance of white matter injury in term newborns with CHD.

NEURODEVELOPMENTAL ABNORMALITIES ARE COMMON IN INFANTS WITH CHD

CHD refers to a variety of malformations of the heart present at birth, and includes both cyanotic and acyanotic types. A seminal study of two forms of cardiopulmonary bypass for the correction of transposition of the great arteries (TGA), a relatively homogeneous type of cyanotic CHD, noted neurological abnormalities in more than a third of enrolled patients.3 4 The identified deficits persisted throughout childhood with considerable detriment to school performance.3 4 Others have noted that compared with population norms newborns with TGA are more likely to have abnormal neurological examinations, learning disabilities and behavioural disorders.5^–7 Motor and global developmental delay is seen in children with multiple types of CHD, in addition to TGA.8 In newborns with hypoplastic left heart syndrome, a type of single ventricle physiology, the incidence of major disabilities in survivors exceeds 60%.9 10 The neurological basis for the high incidence of these global deficits in children with CHD is beginning to be understood with insight from neuroimaging.

THE TIMING OF BRAIN INJURY IN NEWBORNS WITH CONGENITAL HEART DISEASE

The etiology …