For the last one month I can feel my heart beating very fast when I carry something heavy or when walking upward the hill, I feel like it is shaking. I have been having problems sleeping on the left hand side because when I do so, something beats me very fast and hard and I can feel it with my finger, I feel like it is the bottom of the heart because I touch the ribs located there. I just feel that my heart is shaking each time and I don't know what the problem is and I don't sleep on my left nowadays.