I was out of breath.  Carrying an empty suitcase up one flight of stairs, and I was out of breath.  I commented to my husband that we are really out of shape and have to get back to the gym regularly.  I didn’t think it was anything more than being 51 and letting myself go.  What I didn’t realize is that it could have killed me. It was mid-November.  I had a trip to California on business, and as is my practice, I opted for the window seat for all my flights.  I hate getting up during flights.  I like to settle in near the window and try to forget…