Image-based large-eddy simulation in a realistic left heart

• A framework for hemodynamics simulations in patient-specific hearts is presented.
• Heart model and movements are extracted from morphological medical images.
• The simulated blood flow is characterized by its transitional nature.
• Flow dynamics is analyzed and commonly detected physiological patterns are reported.
• Never-reported flow features are discussed for the first time in detail.

A numerical framework allowing insight in fluid dynamics inside patient-specific human hearts is presented. The heart cavities and their wall dynamics are extracted from medical images, with the help of a non-linear image registration algorithm, in order to obtain a patient-specific moving numerical domain. Flow equations are written on a conformal moving computational domain, using an Arbitrary Lagrangian–Eulerian framework. Resulting equations are solved numerically with a fourth-order finite-volume technique. Application of this framework to compute a patient-specific left heart flow is presented as well. The blood flow is characterized by its transitional nature, resulting in a complex cyclic flow. Flow dynamics is analysed in order to reveal the main fluid phenomena and to obtain insights into the physiological patterns commonly detected. It is demonstrated that the flow is neither laminar nor fully turbulent, thus justifying a posteriori the use of Large Eddy Simulation.