Whole-heart modelling with valves in a fluid-structure interaction framework

Computational modelling of whole-heart function is a useful tool to study heart mechanics and haemodynamics. Many existing heart models focus on electromechanical aspect without considering physiological valves and use simplified fluid models instead. In this study we develop a four-chamber heart model featuring realistic chamber geometry, detailed valve modelling, hyperelasticity with fibre architecture and fluid-structure interaction analysis. Our model is used to investigate heart behaviours with different modelling assumptions including restricted/free valve annular dynamics, and with/without heart-pericardium interactions. Our simulation results capture the interactions between valve leaflet and surrounding flow, typical left ventricular flow vortices, typical venous and transvalvular flow waveform, and physiological heart deformations such as atrioventricular plane movement. The improvement of ventricular filling and atrial emptying at early diastole is evident with free annulus. In addition, we find that the added pericardial forces on the heart have a predominant effect on atrial wall deformation especially during atrial contraction, and further help with the atrial filling process. Most importantly, the current study provides a framework for comprehensive multi-physics whole-heart modelling considering all heart valves and fluid-structure interactions.