It's shaped like a retarded pear because that's the way the mammalian heart evolved. Cephalapods for example have 3 more simple 'hearts' to do the job. read more
Why the heart symbol you see everywhere in February doesn't look anything like an actual human heart, though, is a little less clear. The symbol goes at least as far back as the 1400s, when it appeared on European playing cards to mark one of the red suits, though it may even be older than that. The shape is pretty much a mystery, though. read more
It’s shaped like a retarded pear because that’s the way the mammalian heart evolved. Cephalapods for example have 3 more simple ‘hearts’ to do the job. I’m not an evolutionary biologist, but basically it’s taken that form by 500 million years of trial and error to get to what it is. read more
Another theory is the "heart" shape is formed by the back and wings of a dove, which was associated with Aphrodite, the ancient Greek goddess of love. There are many different beliefs by many different historians, which means no one really knows where the symbol originated. It's just one of those mysteries. read more