My DD2 did it every time she got hurt, not just little ouches but head bangs and such, The first time it scared the living daylights out of me... then sad to say i kind of got used to it, she would take the deep breath to scream then just not let it out and pass out, I took her to the Dr and he was blase "yep some babies do that". i would talk to her and blow on her face when she held the breath to long which would get her going again. It was worst between 1 and 2 i think, has not happened in 6 months or so now.
She was never out as long as a minute though... may have felt like forever but in reality i would say she way out 10-15 secs on occasion.