The goal of this observational study is to exploratively investigate intracardiac geometry and hemodynamics in patients with ongoing HeartMate 3-therapy in the Swedish Southeast Healthcare region. The main question it aims to answer is: \- How do different flow levels in the HeartMate 3 left ventricular assist system influence intracardiac geometry and hemodynamics? Participating research subjects are called upon to undergo three followed photon-counting CT scans, as well as certain echocardiographic imaging, all in one session. The research subject's HeartMate device is connected to software that allows for variations in the pump's flow between these image collections. Analyzed variables includes three-dimensional geometry, CFD-computed parameters such as blood velocity, pressure, turbulence, and blood stasis. The variables are related with device settings and, alongside, selected echocardiographic measurements and patient details such as age, BMI, and diagnostic codes for both method validation and comprehensive perspective.