Heche, 53, also had a fractured sternum caused by “blunt trauma,” according to information on the website of the Los Angeles County Medical Examiner-Coroner.
A full autopsy report was still being completed, the coroner’s office said.
The Emmy-winning film and television actor was removed from life support Sunday at a burn center. She was injured when her car jumped a curb and smashed into a West Los Angeles home on Aug. 5. The car and the home burst into flames. Only Heche was injured.
Heche suffered a “severe anoxic brain injury” caused by a lack of oxygen, according to a statement released last week on behalf of her family and friends.
She was declared brain-dead but was kept on life support until her organs could be donated.
Detectives looking into the crash had said narcotics were found in a blood sample taken from Heche. However, police ended their investigation after she was declared brain-dead.
The coroner’s office listed Aug. 11 as her date of death.