WorldStarHipHop founder Lee O'Denat -- known as "Q" -- has died

WorldStarHipHop founder Lee O'Denat -- known as "Q" -- has died ... TMZ has learned.
 We're told Q, the face and CEO of WorldStar, died in his sleep Monday night.
 Q founded the premiere hip-hop website in 2005 when he started posting mixtapes, which gradually progressed into a mash-up of hip-hop videos, fight clips and other outrageous camera footage.
 An autopsy is scheduled for later Tuesday ... although one source tells us Q died of a heart attack.
 He was 43.
 RIP
TMZ