The right ventricle in congenital heart diseases

Right ventricular function is an important determinant of prognosis and outcome in congenital heart diseases. Right ventricular (RV) adaptation to congenital heart diseases (CHD) has many faces as there is a wide variety in defects involving the right ventricle as well as in treatment strategies. This variety induces differences in loading conditions and also changes over time as a result of surgical interventions. Also, treatment practice has evolved changing the nature and outcome of survivors of CHD. Lastly, several lesions also affect the left ventricle (LV) that may interact with RV function and thereby change the RV function. Although in practice sometimes artificially, for educational and conceptual purposes the effects on the RV can be divided into three types of abnormal loading conditions, i.e. increased preload (e.g. shunts or valvular insufficiency), increased afterload (e.g. stenosis or connection to systemic circulation), or a mixture of both. During the process of maturation and ageing and as a result of interventions loading conditions can shift from increased afterload to increased preload. In this chapter we will describe the different faces of the RV with a focus on the functional capacity. We will differentiate between lesions affecting preload, afterload and a mixture of those. Special attention is given to the RV in corrected tetralogy of Fallot and the systemic RV in congenitally corrected transposition of the great arteries or after the atrial switch procedure for transposition of the great arteries.