TMZ broke the story ... Lisa Marie was in full cardiac arrest Thursday morning, before paramedics arrived. We're told her housekeeper found Lisa Marie unresponsive in her bedroom, and just as the housekeeper made that discovery her ex-husband, Danny Keough -- with whom Lisa Marie lives -- returned home from taking their kids to school. He administered CPR until paramedics took over.
Paramedics gave her at least one epinephrine shot and her pulse was restored. She was then rushed to a nearby hospital.