When I was about 7 or so, I was watching a movie with my sister and dancing to the songs and such. When all of a sudden I felt a HUGE rip right in the middle of my chest. I got so scared I ran to my father, and he told me how fast my heart was beating. I calmed down, and everything was fine. Now, I am 14 (100 pounds, about 5"5) and for about the last 5 months or so, i've been getting these feelings where it's almost like my heart stops with a THUD, and starts again. I'm very worried. Please help