Understanding the underlying feedback mechanisms of fluid/solid coupling and the role it plays in heart function is crucial for characterizing normal heart function and its behavior in disease. To improve this understanding, an anatomically accurate computational model of fluid–solid mechanics in the left ventricle is presented which assesses both the passive diastolic and active systolic phases of the heart. Integrating multiple data which characterize the hemodynamical and tissue mechanical properties of the heart, a numerical approach was applied which allows non-conformity in an optimal finite element scheme (J. Comp. Phys., submitted; Fluid–solid coupling for the simulation of left ventricular mechanics, University of Oxford, 2009). This approach is applied to look specifically at left ventricular fluid/solid coupling, allowing quantitative assessment of blood flow through the left ventricle, pressure distributions, activation and the loss of mechanical energy due to viscous dissipation. Copyright © 2010 John Wiley & Sons, Ltd.