Anne-Marie Koop

12 RV function encompasses also RV diastolic function. Parameters reflecting diastolic dysfunctionareE/Aratio 1 ,decelerationtime 2 andE/e’ratio 3 derivedbyechocardiography and the slope of the end diastolic pressure volume relationship, i.e. the end-diastolic elastance (Eed), derived byheart catheterization. However, RVdiastolic function is still insufficiently considered in both clinical practice and scientific research. In chapter 2 we will carefully look into the role of diastolic dysfunction in the progression towards RV failure. In the last decades, CMR is being progressively used to characterize cardiac disease. CMR enables tissue characterization, and may be especially of added value in determining dimensions and function used in more complex RV morphology as in CHD. 20,21 A great advantage is the opportunity for 3D approach instead of the echocardiographic 2D approach. Because of the complex RV anatomy, quality of the views and parameters are dependent of the echocardiographic skills of the executor. In chapter 6 and 7 we illustrate the use of CMR in experimental setting of increased RV pressure overload, as has been described in the protocol presented in chapter 5. Right ventricular physiology Although in utero the LV and RV are exposed to a similar pressure load, in the post- natal period rapid unloading of the RV takes place. 22 Under normal conditions, the adult RV pumps blood into the lung circulation which has a relatively low resistance. In pathologic conditions, RV afterload may increase up to five times, while in pathologic conditions of the LV, i.e. systemic hypertension, afterload will maximally increase up to 50% ( figure 1 ). 23 1 E/A ratio: where E represents the RV pressure during early diastolic filling and A represents the RV pressure during late diastolic filling, caused by the atrial contraction 2 deceleration time: time taken from the maximum E point to baseline 3 E/e’ ratio: where E represents the RV pressure during early diastolic filling and e’ represents myocardial relaxation