There have been many people that have been revived after being dead for a short time and some of them actually have confessed memories of transcendence of some type. Some might describe it as a glimpse of heaven, but its truly impossible to say for certain as it might just be one's imagination running wild shortly after death. We all know the brain still has activity for a reasonable amount of time after one's initial death.
Either way, if you die in your sleep it would be plenty uneventful mentally, but in any other way, how you feel at the moment of death won't last long anyway.