My heart stopped a number of times while asleep, in hospital and measured - up to 4.5 seconds, could it be sleep apnea?

V.dangerous: This almost certainly involves the autonomic (automatic) nervous system and this is like the mechanism of sids; if sugar figures in your pleasures, stop all forms including sweeteners and diet drinks. You also need a supplement of thiamine and magnesium + multivitamin that you can get at a health food store. Do not delay. You are at risk. Sleep apnea comes from the same cause.

Yes it could be: Your next step would be to undergo a sleep study. This will determine if it is sleep apnea.