Hi ive been having thumps in the middle of my chest possibly my heart sometimes followed by dizziness or as if im about to faint when the thump happens it makes me want to take a deep breathe and afterwards I feel like my chest is tight and its hard for me to focus and sometim. Makes me feel nervous what could this be I went to the er a couple times and everything checked out fine.....but one problem it keeps happening its not an everyday thing but it happens to much to the point im woworried. ..