Death note states that if there's no other way a person would die due to a heart attack, but what if when you should die via the death note you have no heart? And no, that's not a silly question, there's a machine used for heart tranplant surgery called extracorporeal circulation system that acts as a sort of heart for the person in which the surgery is being performed on while it's done. So, technically speaking if your name where to be written you could not die due to a heart attack, unless that by heart we would also consider that machine, although this is a bit far fetched. Then if you get another heart or put yours back you have avoided the death note effect, and at this point it has failed to its own rules. From this point I'm not sure what would happen.
I don't think something like that was covered either in the anime or the manga, although I think it would have been an interesting concept to explore, as they could have experimented with that if they wished, but maybe the author explained how things would be like in a case like this one in an interview.
Is there any official explanation or any thing I missed that would give an answer to my question?
Thanks.