The aim of this project is to better evaluate the systemic right ventricular (RV) function in patients with transposition of the great arteries (TGA).

Patients with TGA frequently develop supraventricular and ventricular arrhythmia, conduction problems, systemic atrioventricular valve (SAVV) regurgitation, and congestive heart failure (CHF), all at young age. However, there is variation in time of onset of these adverse events. We want to evaluate ventricular and valvular function at rest, markers of RV fibrosis and cardiac reserve.

Inclusion Criteria:

• Patients with a TGA
• Informed consent to participate. If the patient is under the age of 18, the assent of the patient and the permission of the parents to participate

Exclusion Criteria:

• Previous double-switch intervention
• Any medical contra-indication for cardiovascular magnetic resonance (CMR) imaging (e.g. pacemaker)
• The presence of exercise-induced arrhythmia, symptomatic myocardial ischemia, a resting systolic blood pressure > 200 mm Hg and/or diastolic blood pressure > 110 mm Hg, New York Heart Association (NYHA) class III or IV, or non-cardiac co-morbidity that could aggravate by exercise
• Additional exclusion criterion for delayed gadolinium enhancement CMR: any medical contra-indication for intravenous gadolinium

Patients with a transposition of the great arteries (TGA)