Sandra "Sandy" Herold, 72, died at her home in North Stamford when an artery ruptured, the Stamford (Conn.) Advocate reports.
Attorney Robert Golger says the near-death of Herold's friend Charla Nash, the resulting lawsuit and the death of Herold's husband, all played a part in her demise.
"In the end, her heart, which had been broken so many times before, could take no more," Golger said.
Herold's chimp Travis went berserk and attacked Nash on Feb. 16, 2009.
Nash sued Herold for $50 million.