Maricopa County spokeswoman Cari Gerchick said that's the finding from an autopsy conducted Thursday by the county medical examiner's office.
The 54-year-old wrestler's given name was James Hellwig. He collapsed April 8 while walking with his wife to their car at a Scottsdale hotel and was pronounced dead at a hospital.
Scottsdale police have said there were no signs of foul play.
The Ultimate Warrior was one of pro wrestling's biggest stars in the late 1980s.
Triple H Remembers The Ultimate Warrior
WWE executive vice president Paul "Triple H" Levesque discusses the death of wrestling icon The Ultimate Warrior.