Geert Kleinnibbelink

General Introduction and Outline of Thesis 25 1 the relative contribution of longitudinal mechanics to area change, and so provides novel haemodynamic insights into RV function ( Figure 6 ). The RV strain-area loop has been applied in cross-sectional studies to describe and demonstrate different characteristics among different type of sports 49 , however, it has not been used in demonstrating RV mechanical adaption in training studies. Previously, our group has demonstrated that the is associated with changes in afterload in PAH patients. 55 In summary, the RV strain-area loop may provide additional insight into physiology as well as pathophysiology, which will both be further explored in this thesis. RV area (cm 2 ) RV longitudinal strain (%) ESA EDA a. ESslope b. Sslope c. Peak strain d. Uncoupling ED e. Uncoupling LD f. Uncoupling g. EDslope h. LDslope 0 0 -21 a b c e d 100% of EDA 40% of EDA 25 f g h Figure 6 . Example of a RV strain-area loop. The thick black line represents the systolic strain area relation whilst the thin black line represents the diastolic strain-volume relation. Several loop related parameters can be derived: (a) early linear slope during first 5% of volume ejection in systole (ESslope), (b) the overall linear slope during systole (Sslope) and (c) end-systolic peak longitudinal strain (peak strain). Furthermore, (d) early, (e) late diastolic and (f ) overall (un)coupling which is defined as the relationship between systolic and diastolic strain (difference in strain) for any given area. Lastly, (g) the early linear slope during first 5% (EDslope) and (h) late linear slope (LDslope) during last 5% of volume increase in diastole.