Lost love really can cause a broken heart
Study: Tragic events linked to chest pain, shortness of breath
Confirming the wisdom of the poets and philosophers, doctors say the sudden death of a loved one really can cause a broken heart. In fact, they have dubbed the condition "broken heart syndrome."
In a study published just in time for Valentine's Day, doctors reported how a tragic or shocking event can stun the heart and produce classic heart attack-like symptoms, including chest pain, shortness of breath and fluid in the lungs.
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http://www.msnbc.msn.com/id/6941271/
It doesn't cause the heart to break, it just messes with your emotion and stress and stuff which sends you over the top, if you react that much to love, you probably had problems anyway, don't assume you were in perfect health just because love makes you feel like perfection.
Quotebroken heart
Surly everyone on this forum knows that it is your heart chakra (energy center) thats that gives you the feeling of a broken heart. It is not your real heart.
http://www.kheper.net/topics/chakras/Heart.htm