A project I'm looking at requires a fairly attractive animated heart. The point of it is the heart has a faulty valve, and it needs to be shown how a certain thing will change how this valve is working - a simple version is the valve is torn and we need to pin it back together. So you'd have the main heart animation beating away, and then the valve would have a broken animation, fixed animation and probably some in-between animation showing the medical thing taking place (while the heart is beating). I know little about animation from an artist's perspective. I'm not looking to do this myself, I just would like to know what form of animation/modelling is sensible here? Is simple bone-based animation the correct choice? It has to be something creatable in 3DS/Maya; the guy in charge is on the graphical design side and has access to modellers, but I believe we need someone with a focus on real-time/game modelling for this. Any advice is welcome. If anyone's potentially interested in working on this on a paid basis, PM me as the project leader is happy for me to find some quotes for this.

It may be easier to buy an animated heart model and edit it, realistic medical models are not cheap but professional artists aren't cheap either.
Have a look at 3D Science the detailed model costs $4800 with Textures and Animation.

It doesn't need to be hugely detailed. Apart from the main shape and heart-beat animation, the only detail is really needed on the valves. We also need to be able to see inside the heart, making selected parts invisible (like an atrium or one entire side of the heart).