Ultra-high frame rate echocardiography for improving left ventricular diastolic function assessment

Diastolic function (DF) of the left ventricle (LV) is impaired in most pathologies of the heart and can even become the dominant problem in some disease. Invasive heart catheterization can describe diastolic properties of the LV very well, but is not feasible for repeated use in the follow-up of patients. Therefore, current guidelines propose a multi-parametric echocardiographic assessment of DF, which, however, is complex and prone to misinterpretation of measurements. Potentially interesting features of LV diastolic motion and deformation cannot be assessed with commercial ultrasound machines, as their temporal resolution (ca. 70 frames/s) is far too low. We therefore propose to use ultra-high frame rate (UHFR) echocardiography in the range of 5000 frames/s for a better assessment of LV DF. UHFR echocardiography can also be used for shear wave imaging, i.e. the measurement of mechanical waves inside the myocardium which are caused by a mechanical excitation (e.g. by a strong ultrasound impulse). The propagation speed of the shear waves is directly related to myocardial stiffness and, therefore a direct surrogate of DF. Our lab has vast experience in UHFR imaging and all necessary expertise and equipment to implement shear wave and other imaging modalities for better DF assessment. The aim of the proposed research is to implement the above mentioned imaging sequences, to validate them in phantoms, animal studies and volunteers, and to finally apply them in a clinical study.