Heart failure with preserved ejection fraction (HFpEF) affects approximately 1% of the Dutch population and is increasing in prevalence every year. While the presentations of HFpEF vary considerably, it is primarily a dysfunction of the filling phase of the heart, where the left ventricle is not able to relax efficiently and requires increased filling pressures to achieve the same cardiac output. Earlier diagnosis is a critical step forward for effective management of the syndrome, but the gold standard for measuring diastolic filling pressures is by invasive heart catherization, which has limited applicability for early recognition of diastolic dysfunction. Echocardiography is the primary imaging modality for diagnosis of HFpEF but current clinically recommended metrics are either insensitive or unspecific, especially at the early stages of disease progression. Part of the limitation of current echocardiography is the reliance on ultrasound Doppler for haemodynamic measurements, which is limited to only estimating the 1-dimensional blood flow components towards or away from the probe, providing a limited view of intracardiac haemodynamics.
I propose to use state-of-the-art high frame rate 3-dimensional, contrast enhanced echocardiography to measure the haemodynamics in the left ventricle with unparalleled temporal resolution. This technique, termed 4D-flow echocardiography, is capable of quantifying not only the blood flow in 4-dimensions (3- spatial dimensions + time), but by using physics-informed regularisation, the pressure gradients within the left ventricle can be estimated. This technique has potential for improved understanding of the haemodynamic mechanisms of left ventricular diastolic dysfunction as well as a tool for early stage identification of individuals at risk of developing HFpEF.
In this project I will develop and validate my 4D-flow echocardiography technique using a state-of-the-art matrix ultrasound probe, both with in vitro and in pigs. The outcome of this project is a novel tool that can be used by cardiologists and biomedical researchers for the study and diagnosis of diastolic dysfunction.