The project aims toward clarifying the underlying mechanism and the long-term impact of congenital heart disease on neurodevelopment.

The project provides detailed information on the impact of congenital heart disease on neurodevelopmental outcome in adulthood. The study investigates if brain maturation and development, and the neurocognitive outcome is compromised in patients with atrial or ventricular septal defects more than 20 years after diagnosis and treatment. Data on brain morphology, brain tissue architecture, and resting-state function will be obtained by 3.0 Tesla MRI. Data on neurocognitive outcome will be obtained by a customized wide neuropsychological test battery. This study will clarify the extent of these patients' neurodevelopmental challenges and guide evaluate targeted interventions to alleviate potentially long-term effects.

Inclusion Criteria:

• ICD codes DX Q21.0 (VSD) or DX Q21.1 (ASD), surgically repaired VSD or open ASD

Exclusion Criteria:

• lack of medical record, suffering from coronary artery disease or other congenital cardiac abnormalities, diagnosed syndromes, spontaneous closure of the atrial septum defect before inclusion-date, magnetic implants or non-MRI compatible foreign objects, pregnancy, lack of Danish language skills or suffering from severe lung disease

Participants are either adults who in childhood were diagnosed with an ASD or VSD, or healthy matched controls.