Fiona may be able to answer this better as she works on hearts but I don’t think so. The horses heart is similar in appearance to humans but much larger (the horses heart pumps blood around a very large animal) and has a different electrical signal that produces heart beats… I think. Both these this make it very difficult to transplant horses hearts. I think pig hearts are very similar to human hearts and they use to put pigs hearts into humans back in the early days of heart transplantation..
it would of been so cool to have been a pioneering surgeon who transplant the first heart…
What Justin said is correct (mostly :P) – I’m just going to add to it.
The horse heart works the same way as the humans and does a pig, but they are just not the right size. The horse is a much bigger animal, has a lot more muscle and so has a bigger heart. If you try put that in a human then our lungs would be crushed.
The other problem is that each heart cell has a label on it saying that is ours. If you try to put something that is not ours into our body, then our body will try to kill it off. So if you put a horses heart into a human, the body will kill off the heart anyway and the person would die.