Joanie Simpson woke early one morning with a terrible backache. Her chest started hurting when she turned over. Within 20 minutes, she was at a local emergency room. Soon she was being airlifted to a hospital in Houston, where physicians were preparing to receive a patient exhibiting the classic signs of a heart attack. But tests at Memorial Hermann hospital revealed something very different. Doctors instead diagnosed Simpson with Takotsubo cardiomyopathy, a condition with symptoms that mimic heart attacks. It usually occurs following an emotional event such as the loss of a spouse or child. That link has given the illness its more colloquial name: Broken-heart syndrome. In Simpson's case, the event that she says tipped her over the edge was the recent death of her beloved Yorkshire terrier, Meha. "I was close to inconsolable," she said. "I really took it really, really hard." Simpson's 2016 experience is described this week in the New England Journal of Medicine - not because of the dog's role, according to one of her doctors, Abhishek Maiti, but because hers was a "very concise, elegant case" of a fascinating condition that research has established as quite real and sometimes fatal. Although not the first published case linking broken-heart syndrome to stress over a pet's death, it underscores something many animal owners take as a given: That grieving for sick or deceased pets can be as gutting as grieving for humans. A growing body of research supports this notion, which was echoed in a recent study that found pet owners with chronically ill animals have higher levels of "caregiver burden," stress and anxiety. It's the flip side of evidence that links pets to health and happiness, which gets more attention. Not that people who have lost beloved animals are likely to be surprised. Simpson certainly wasn't shocked. At the time of what she calls her "episode," she'd been having a rough stretch: Her son was facing back surgery. Her son-in-law had lost his job. A property sale was proving to be complicated and lengthy. Meanwhile, 9-year-old Meha was suffering from congestive heart failure. The dog was like a daughter, Simpson said. She adored jumping into the