question: I feel quite stressed and have done for a long time.  I have a constant tight feeling in my chest, particularly under my left breast and into my left arm pit.  A few weeks ago i was sitting talking to a friend, leaned slightly to the left side and got very sharp fluttering type pains where my heart is.  These caused me to feel very breathless and if I took in a breath the pain was worse.  the pains lasted for about 20 mins.  I had another episode the next day which lasted a few minutes.  I have had these previously once or twice.  What do you think the cause is?