What Happens When Your Heart Stops

Recently, someone asked me this question:  "What happened when your heart stopped"?  I have been asked many questions since the Sudden Cardiac Arrest (SCA) in 2009, but not quite that one.  There was part of me that wanted to respond: "Nothing much."  But that's not the nicest part of me; that part is a tad sarcastic, so I refrained.

After a second or two, I realized they were asking (with the best of intentions) what I felt or what I remember that I felt as the arrest happened.  So I recounted:  I was sitting there staring at a wall across the way, my vision went to a tunnel and I was out. The next thing I remember was waking up with a whole bunch of very loud people scurrying about, trying to put an oxygen mask on my face (that I wasn't having any of), telling me I was OK.  Well, aside from the fact that you have no idea what happened  -- you are pretty sure it was NOT ok - that was about it.  That is all I remember.  I have no recollection of the three shocks with the paddles or any of the rest of it.

As the arrest happened, my vision went to a tunnel.  (Many months later, I learned from a Sanjay Gupta, MD television special that there is a reason for the tunnel.  Apparently, the retina is exceptionally sensitive to the loss of blood flow, so darkness arrives in that last second of consciousness.
But I report, I did not see a bright light, I did not see a halo, I did not see Mom motioning me from the other side.
My only memory is going out with that tunnel.

So "what happens when your heart stops?"  Hell if I know.  And not all that eager to find out.