Imaging Assessment of Diastolic Function

Diastolic function is poorly studied in children with congenital heart disease. This is mainly due to the lack of validated techniques. Cardiac MRI offers two advantages compared to echocardiography: 1. accurate measurements of ventricular volumes and mass; 2. tissue characterization. The main advantage of echocardiography is a better temporal resolution which allows the study of short events like early relaxation. Overall there is a lack of studies correlating different echocardiographic and MRI parameters of heart function in pediatric populations with congenital or acquired heart diseases. This study will address specific questions on specific groups of patients that might bring more insight into chamber interaction and cardiac function. This study hypothesizes the following: * Atrial enlargement is a marker of chronic increase in filling pressures and 3D echo might be the best method for follow-up. * Cardiac remodeling associated with chronic loading results in changes in diastolic properties related to changes in cardiac mass and volume. This is related to changes in cardiac mechanics influencing diastolic parameters. Especially the influence on twisting and untwisting will be studied. * Regional myocardial fibrosis and scarring may account for regional systolic and diastolic dysfunction with possible prognostic impact