SANTA FE, N.M. >> Actor Gene Hackman died of heart disease a full week after his wife died from hantavirus in their New Mexico hillside home, and he may not have been aware she was dead because he showed severe signs of Alzheimer’s disease, authorities revealed Friday.

Both deaths were ruled to be from natural causes, chief medical examiner Dr. Heather Jarrell said alongside state fire and health officials at a news conference.

“Mr. Hackman showed evidence of advanced Alzheimer’s disease,” Jarrell said. “He was in a very poor state of health. He had significant heart disease, and I think ultimately that’s what resulted in his death.”

Authorities ruled out foul play after the bodies of Hackman, 95, and Betsy Arakawa, 65, were discovered Feb 26. Immediate tests for carbon monoxide poisoning were negative.

Investigators found that the last known communication and activity from Arakawa was Feb. 11 when she visited a pharmacy, a pet store and a farm market, Santa Fe County Sheriff Adan Mendoza said Friday.

Hackman’s pacemaker last showed signs of activity a week later and that he had an abnormal heart rhythm Feb. 18., the day he likely died, Jarrell said.

“It’s quite possible he was not aware she was deceased,” Jarrell said.

Their bodies were found a little over a week later. Hackman was found in the home’s entryway. His death was tied to heart disease with Alzheimer’s disease contributing.

Arakawa was found in a bathroom. Authorities linked her death to hantavirus pulmonary syndrome, a rare but potentially fatal disease spread by infected rodent droppings. Thyroid medication pills prescribed to Arakawa were found nearby and weren’t listed as contributing to her death, Jarrell said.

Hantavirus is typically is reported in spring and summer, often due to exposures that occur when people are near mouse droppings in homes, sheds or poorly ventilated areas. This is the first confirmed case of hantavirus in New Mexico this year.