Heather North, longtime voice of Scooby-Doo's Daphne, died of a heart attack brought on by respiratory disease, TMZ reports.
North's death certificate lists her official cause of death as cardiopulmonary arrest with an underlying cause of constrictive bronchioliti. The death certificate also lists North as having had Hypoxemia, or an abnormally low level of oxygen in the blood.
North passed away on November 29 at the age of 71. A memorial service was held Wednesday, December 20 in Studio City, Los Angeles.
The actress voiced Daphne in seasons 2 and 3 of Scooby-Doo, Where Are You!, two seasons of The New Scooby-Doo Movies, 16 episodes of The Scooby-Doo/Dynomutt Hour, and 40 episodes of The Scooby-Doo Show.
North continued to lend her voice to the red-haired "jeepers!"-exclaiming investigator in various Scooby-Doo movies and television shows until 2003's Scooby-Doo! and the Monster of Mexico.
She is survived by her son Kevin, daughter-in-law Stephanie; stepdaughter Nina and her husband Brent; stepson Wes and his wife Leslie; and granddaughter Jocelyn.