We consider the numerical simulation of integrated heart models for the study of the cardiac functioning with particular emphasis on the coupling of the muscle contraction, the fluid dynamics of the left ventricle, and the interaction with the valves. We address the numerical approximation of the blood flows inside the left ventricle by using the Finite Element method for the spatial approximation of the fluid–structure interaction problem together with the aortic valve and the cardiac muscle, specifically when the contraction of the latter is driven by electromechanical models. We present and discuss numerical results for the fluid dynamics of the left ventricle by analyzing the role of different coupling strategies.