I forgot to even post the other theory..
Some say that constriction causes heart attack or stroke by putting so much pressure on the blood vessels.. That seemed more likely to me, especially with smaller prey like mice.. Seems that there would be enough oxygen in the blood even to last longer than 8 seconds. Naturally, I run all my scientific questions through the 'seems to me' test so there you have it, lol..
Here's what I was looking for..
http://journals.cambridge.org/action...line&aid=54353