I don't drink and I have mine when I am sleeping, when I am driving my car,when I am watching a movie...so it seems to be when i am at rest that I have it.   I have been having them on and of (maybe 3 or 4 times a week) for the past few years and 4 months ago I took a severe one and ended up in emerge by ambulance but was told that I didn't have a heart attack.  I failed a stress test and than had a mibi test (another type of stress test) and I again failed the threadmill part of the test but passed the resting part of it.  They believe it has something to do with the muscles around the heart or damage to the wall of the heart.  My appointment with the cardoligist got cancelled lst week so I am now waiting for a call to have my appt. rescheduled and hopefully can find out where to go from here.  My pain is in the left breast and radiates to the left side of the breast and under the arm and it is not nice at all.  sometimes it lasts for 5 or 10 minutes but can last up to half hour..I will post again if I get a diagnosis