I don’t know the reasons why emotional pain is often accompanied by physical pain but consider that the opposite is often true as well. Emotional delight is often accompanied by feelings of euphoria and exhilaration. In the exuberant case the (physical) feelings are often attributed to endorphins or adrenalin. I suppose something similar occurs to accompany bad news.
The notion of the heart as the seat of emotions is widespread but certainly not universal. The early Maoris thought the kidneys fulfilled that role. When the Bible was translated into Maori the term they used for the emotional center was, IIRC, ngakau which is usually translated as kidneys. This creates some unusual imagery for us poor westerners. “Who shall ascend unto the hill of the Lord?”, the Psalmist asks. The answer? “He that hath clean hands and pure kidneys.”
“pluto … a seriously demented but oddly addictive presence here.” – TVeblen
Haven’t you ever heard that the way to a man’s heart is through his stomach? Well, it turns out that the reverse is also true. The nerve bundle that runs through the center of the chest contains nerves from both the stomach and the heart. The body is notoriously bad at mixing signals.
So what happens is that when you experience a “heartbreaking” experience, you feel increased anxiety and stress. And what’s associated with anxiety and stress? Ulcers and acid reflux. Heartburn.
So all those poor creatures in the folk songs who died of a broken heart (Anachie Gordon, etc.) – well, they should have taken antacids.
You guys laugh at the Maori kidneys all you want. Just remember that in European history, the Romans thought that all emotions (including love) had their source in the bowels.