We were doing this on the playground in 1963 & 1964.
When discussed at home, we were warned that it could do permanent damage to the heart.
No mention of death back then.
For clarification, we were holding our breath in crouched position, and sometimes kids would pass out.
Never used strangulation devices around the neck.
I don't recall it ever having, apparently, reached epidemic proportions. In fact, I've never heard of it at all 'til recently.
We tried a variant in my Catholic school in 1976 or so.
One kid would squat against the wall, take ten deep breaths, breath the last one all the way out, and then stand up. All the other kids would then press his chest against the wall, so he couldn't breath in.
The world would go all blurry then disappear, and then you would slowly wake up with everybody standing around you laughing.
The nuns went ballistic when they found out about it, after one kid took about twenty minutes to wake up.
I have no idea who thought the game up, or why we all did it. Probably because we were 12 years old and dopey.