Did Debbie Reynolds die of broken-heart syndrome?

Dying of a broken heart is real.

When Debbie Reynolds passed away this week, her son said the stress of his sister Carrie Fisher's death the day before was too much for his mother to take.

The emotional distress of losing a loved one can trigger broken-heart syndrome, a recognized medical condition that disproportionately affects women and can be fatal.

"A 'broken heart' really is an event where the heart ceases to function normally and is prone to heart rhythm abnormalities," said Dr. Mark Creager, director of the Dartmouth-Hitchcock Heart and Vascular Center in New Hampshire and past president of the American Heart Association. "That term is used to explain a very real phenomenon that does occur in patients who have been exposed to sudden emotional stress or extremely devastating circumstances."

Known medically as stress-induced cardiomyopathy or takotsubo syndrome, it can strike anyone, even those in good health with no previous heart problems.

Reynolds, who suffered two strokes in 2015 but recovered, was taken by ambulance to a hospital the day after Fisher died.

"She said, 'I want to be with Carrie,'" Reynolds' son, Todd Fisher, told The Associated Press. "And then she was gone."

No cause of death has been disclosed for either woman.

Broken-heart syndrome is when a surge of stress hormones, such as adrenaline and cortisol, cause arteries to seize, limiting blood flow to the heart. The experience - and diagnosis - is often confused with heart attack, Creager said.

Both conditions look the same on an electrocardiogram, said cardiologist Dr. Holly Andersen, director of education for the heart institute at New York Presbyterian Hospital and scientific adviser for the Women's Heart Alliance. But where heart attacks are caused by blocked arteries, there are no such blockages in "broken" hearts.

The condition can be treated, and even heal untreated, she said, but it can also cause heart arrhythmias and sudden death.

Japanese researchers were the first to describe broken-heart syndrome in 1990. They named it takotsubo, which means "octopus pot," for the way the malfunctioning heart appears in imaging studies.

Andersen has not treated Reynolds, but she suspects the actress succumbed to "a cardiovascular event," noting Reynolds' history of stroke and the prevalence of heart disease among women.

"It wouldn't be surprising that an 84-year-old woman like Debbie Reynolds had some (arterial) plaque, and with this kind of stress, became more vulnerable and had more of a garden-variety heart attack and sudden death," Andersen said. "But you don't have to have any predisposing disease and you could be still susceptible to sudden death from (takotsubo) syndrome because of overwhelming emotional stress."

Barbra Streisand, an advocate for women's cardiovascular health, said in a statement Thursday that "too many women die of heart disease and stroke like mother and child Debbie Reynolds and Carrie Fisher."

Streisand gave $10 million in 2012 to create her namesake Women's Heart Center at Cedars-Sinai Medical Center in Los Angeles, a research and treatment facility. Heart disease is the No. 1 killer of women, but until recently, research has been done almost exclusively on men.

Women's hearts are smaller and beat faster at rest than men's, Andersen said: "There's no question that, physiologically, when you put everything together - the nerves and the blood vessels - that (women's) hearts work differently and get disease differently."

"We need to study more women," she said. "We're under-researched. We're under-treated. But even if you control for all the differences that we know about, we're still more likely to die from heart disease than a man."

Carrie Fisher reportedly suffered a heart attack aboard a flight that led to her death four days later.

Women also get other forms of heart disease more frequently than men, Creager said. Takotsubo syndrome is one example.

The American Heart Association is working with Streisand's heart center to study women, heart attacks and heart disease, he said.

Scientists don't know exactly why takotsubo syndrome primarily affects women, but they think it has something to do with the female stress response and the way women's brains and bodies process emotions.

If fans of Debbie Reynolds and Carrie Fisher want to take a health lesson from the women's tragic, successive deaths, Creager and Andersen hope it will be recognized as the literal vulnerability of women's hearts. Forty percent of women don't experience chest pain during a heart attack, Andersen said, and a recent survey showed that women often neglect to call 911 even when they think they are having a heart attack.

"The majority know that something's wrong," Andersen said. "Jaw pain, back pain, sweating, an overwhelming sense of fatigue. There's a feeling that something's wrong. It could be shortness of breath or crazy indigestion. But we'd much rather be taking care of acid reflux or indigestion in the emergency room than missing a heart attack, so please come in if you think something's wrong.

"You really can die of a broken heart."