PhD defence L.B.H. (Lana) Keijzer

The clinical aim of this thesis was the development of a non-invasive method to directly assess myocardial stiffness. This is relevant for the assessment of myocardial stiffening in people at risk for developing heart failure, and potentially for the diagnosis of underlying pathophysiologies in patients with heart failure with a preserved ejection fraction. The focus of this thesis was the accurate measurement and interpretation of natural shear waves after valve closure, using novel high frame rate ultrasound imaging techniques. The propagation speed of these shear waves is assumed to be linked to the myocardial stiffness. This thesis shows that shear wave elastography measurements are feasible in healthy volunteers, and measurements are currently performed in 2 patient studies.  In addition, this thesis shows that these natural shear waves after valve closure represent a mixed state of passive myocardial stiffness, relaxation, contraction and loading. Therefore, although natural shear waves can potentially be used to detect an increased myocardial stiffness, it is likely that a combination with other techniques is required to further distinguish the contributions of passive myocardial stiffness, relaxation and contraction. This project was financed through the ‘Early recognition of Cardiovascular disease’ call 2015, a public-private partnership between NWO-Applied Engineering Science and the Dutch heart foundation, project EFFECTS (1 milion euro). Executed in collaboration with Erasmus MC, Delft University of Technology, KU Leuven (Belgium), and Mindray/Zonare Ultrasound.

Due to corona, the PhD defences do not take place publicly in the usual way in the Senate Hall of the Professor Andries Querido Room. The candidates will defend their dissertation either in a small group or online.