I have had this sensation since I was little and I remember the doctor saying it was just "growing pains". I can remember telling my mom, even at my young age, that it was something more. Now I am 27 and I still get them. I also have palpitations and diagnosed myself with Mitral Valve Prolapse (I am a nurse so we tend to self-diagnose). After having a cardiac Echo done, they attributed my palpitations to a "leaky mitral valve" but apparently not severe enough to call it Mitral Valve Prolapse. I definitely believe there is a connection in all of it. During the attacks, it always helps if I lean over. It feels like it takes pressure off of my heart and opens my chest up. It is so interesting to read everyones stories. I never knew this was an actaul condition until I decided to research it more.