Geert Kleinnibbelink

Chapter 10 198 During the past two decades, the right ventricle (RV) has received increasing scientific and medical interest. Although the importance of imaging and assessing RV structure and function is clear in multiple clinical scenarios, use of non-invasive echocardiographic techniques to follow-up patients with pulmonary hypertension (PH) is limited. Likewise, RV structure and function in the athlete’s heart has been studied to aid differentiation from cardiomyopathies, such as arrhythmogenic RV cardiomyopathy, that increase the risk of sudden cardiac death and could be identified in pre-participation screening or secondary care. The general aim of this thesis was to investigate the acute and chronic effects of load challenges, either induced by pathological (e.g. PH) or physiological stimuli (e.g., exercise), on RV structure, function and mechanics. For this purpose, we have used novel echocardiographic techniques, namely speckle tracking echocardiography and the strain-area loop. In this final chapter, we will discuss and integrate the findings of this thesis with the existing literature and any future directions for research. 10.1 – Relevance of evaluation during and post-acute exercise For many decades, cardiopulmonary exercise testing has been used to evaluate cardiovascular conditions, providing information on exercise capacity, heart rate (and rhythm) and blood pressure during exercise. 1-3 Exercise testing may have even further potential for clinical use in the diagnosis or prognosis of cardiovascular disease. Indeed, following an acute bout of exercise, a temporary increase of cardiac biomarkers is found (e.g. troponin and natriuretic peptide [BNP]) 4 , but also a reduction in systolic cardiac function (i.e. exercise-induced cardiac fatigue [EICF]) 5 or decrease in blood pressure (post- exercise hypotension [PEH]) 6 ( Figure 1 ). Interestingly, exercise-related changes in these markers may have clinical potential as the magnitude of these exercise-induced changes seem to relate to clinical outcomes. 7-9 To further explore the potential of exercise-induced changes, in this thesis, we evaluated cardiac function during exercise to evaluate EICF ( Chapter 2 ) and further investigated the relevance of PEH ( Chapter 5 ). Findings of these chapters will be discussed below to support the wider use of measures of cardiovascular function during and post- exercise for improved (patho)physiological insight and clinical use.