I am getting a thudding in my chest , right about under my left breast . I feel short of breath and it last 0.5 to 1 hour. I am very healthy, on bp pills but am soon going to quit them as I started running, lost 60 lbs and feeling great. Alot of family history of heart related problems. father had 3 heart attacks, grandmother and grandfather also. Mother had series of mini strokes at 65. I worry alot , have alot of stress .