Three-dimensional echocardiography in adults with congenital heart disease: a scientific statement of the European Society of Cardiology Working Group on Adult Congenital Heart Disease and the European Association of Cardiovascular Imaging of the European Society of Cardiology.

Congenital heart disease (CHD) is the most common inborn defect affecting up to 1% of newborns. The prevalence of CHD has shifted from childhood to adulthood, and the number of adult patients living with CHD continues to increase. This patient population presents unique challenges in diagnostic imaging and management due to complex underlying cardiac morphology, previous operations and interventions, and haemodynamic conditions. 3D echocardiography (3DE) has significantly improved our understanding of complex anatomic and haemodynamic substrates and emerged as a clinically useful tool that provides incremental information and complements the routine echocardiographic examination. The advantages of 3DE, including more accurate visualization of anatomic structures, absence of geometrical assumptions regarding shape of cardiac structures, and ability to obtain a complete view of the structures of interest from multiple perspectives in a beating heart, are especially relevant for diagnosis and follow-up of CHD in adult population, as well as interventional and surgical planning and guidance. In this scientific statement, we provide detailed and simple-to-follow descriptions of the added value of 3DE in evaluation of specific cardiac structures encountered in CHD, its role in diagnosis and follow-up, and training requirements for proficiency in 3DE in adult CHD.