Our hearts go out to the brilliant actor Patton Oswalt and his family in their grief.

Patton Oswalt’s wife, Michelle McNamara, died abruptly in her sleep at the age of 46 about a year ago, and the comic has revealed the cause of her death.

The actor and comedian told the Associated Press on Friday, “We learned today that the combination of medicines in Michelle’s system, along with an illness we were unaware of, proved devastating.”

Oswalt explained that the pair, who married in 2005, had “no notion” she had a disease that caused her arteries to constrict.