It's unclear what led to Debbie Reynolds' death just one day after her daughter Carrie Fisher died - but it's been scientifically proven that emotionally traumatic events can trigger a surge in stress hormones.
Those hormones are felt to "stun" the heart and prevent it from pumping properly, or cause an artery supplying the heart to go into spasm.
Cardiologist Harmony Reynolds of New York University's Langone Medical Center has studied this under-recognised condition.
She says it occurs mainly in older women, many of whom have no obvious pre-existing heart disease.
"This is a heart attack syndrome that, unlike a typical heart attack, occurs with the arteries completely open," Dr Reynolds said.
"The area of the heart is quite large, but if people survive the event, it all goes away."
Symptoms can resemble a heart attack including chest pain and shortness of breath, but may be subtle, causing women to delay seeking help.
"We don't understand why an emotional connection exists, but the brain and heart are connected. You can die of heartbreak, but exactly how that happens and exactly why, we don't know," Dr Reynolds explained.