The idea that vampires die when placing a stake through their heart is so funny to me, because most things die once you've put a stake through their heart...
I think the idea is that vampires don't die unless you put a stake through their heart. Most things have many other ways of killing them.
I thought sunlight and water also kills them.
I think the original idea was vampires don't stay dead unless they're staked through the heart.
But most things die if you put the stake through their brain. Vampires only die if it goes through the heart. I'm thinking of one of Saberhagen's vampire stories where the vampire's car (or perhaps he was a passenger??) has a bomb that goes off, as it goes boom the vampire is worried about whether any of the dash is made of wood.