I have been having a strange "Flutter" feeling on the left side of my chest just below my pectoral muscle. The feeling is painless just a strange uncomfortable feeling, almost like a muscle tic but on the inside. I don't have shortness of breath and no pain but I suffer from anxiety and have anxiety attacks which this seems to trigger. I have told myself this is not going to kill me & have been able to stem the anxiety attacks to a certain extent. However because this strange unexplainable "Flutter" occurs My mind wants to trigger an anxiety attack. This flutter happens with no rhyme or reason. I can be sitting,standing moving, bending,at rest or on the move. It has occurred in each of these incidents but not always and without warning. It lasts between 1`sec & 3 sec. I am hoping this is not a serious issue and am anxious for insight from anyone as to severity of this and how concerned I need to be. I appreciate all insight