Takotsubo syndrome, or broken-heart syndrome, is a rare condition characterized by a weakening of the heart muscles. It can cause chest pains and loss of breath. The condition can even be fatal for those who develop cardiogenic shock, when the heart can't pump enough blood to the body as a result. For those who survive but have cardiogenic shock, they can still die from complications of broken-heart syndrome years later.

While broken-heart syndrome has been linked to a stressful event in a person's life, research shows that happy occasions may trigger its onset as well.

Broken-heart syndrome causes the heart's left ventricle to swell at the bottom while remaining narrow at the top, making it look similar to an octopus trap, hence the Japanese name "takotsubo," which means octopus pot.

The research on the condition, which was published in the European Heart Journal, looked at data from 1,750 patients who had been diagnosed with broken-heart syndrome worldwide. Using information from the International Takotsubo Registry, a database housed at the University Hospital Zurich in Switzerland, researchers noted that 485 patients developed the condition following a definitive emotional trigger.

Of the patients who developed the condition after a trigger, the overwhelming majority — 96 percent — had experienced a sad or traumatic event such as the death of a family member, a recent divorce, an accident, illness or a relationship problem. But the remaining 4 percent developed broken-heart syndrome after a happy or joyful event, such as a birthday party, wedding, or even a favorite team winning a big game.

The majority of broken-heart syndrome patients, whether the condition was triggered by a happy or sad event, were post-menopausal women, leading researchers to believe that irregular surges of hormones may contribute to the condition.

This study is helping researchers get a better look at the intertwined feedback mechanisms within the body. Researchers hope to study the brain wave patterns of patients who experience "happy-heart syndrome," and compare them to those experiencing the "broken-heart" variety so they can better understand the interactions of the brain and the heart and how emotions are processed within the body.

Editor's note: This article has been updated since it was originally published in March 2016.

Too much happiness can lead to a broken heart
Takotsubo syndrome or 'broken-heart syndrome' is typically linked to stress or grief, but it can be caused by happy events, too.