Causes

The exact cause of broken heart syndrome is unclear. It's thought that a surge of stress hormones, such as adrenaline, might temporarily damage the hearts of some people. How these hormones might hurt the heart or whether something else is responsible isn't completely clear.

A temporary constriction of the large or small arteries of the heart has been suspected to play a role. People who have broken heart syndrome may also have a difference in the structure of the heart muscle.

Broken heart syndrome is often preceded by an intense physical or emotional event. Some potential triggers of broken heart syndrome are:

• The death of a loved one
• A frightening medical diagnosis
• Domestic abuse
• Losing — or even winning — a lot of money
• Strong arguments
• A surprise party
• Public speaking
• Job loss or financial difficulty
• Divorce
• Physical stressors, such as an asthma attack, COVID-19 infection, a broken bone or major surgery

It's also possible that some drugs, rarely, may cause broken heart syndrome by causing a surge of stress hormones. Drugs that may contribute to broken heart syndrome include:

• Epinephrine (EpiPen, EpiPen Jr.), which is used to treat severe allergic reactions or a severe asthma attack
• Duloxetine (Cymbalta), a medication given to treat nerve problems in people with diabetes, or as a treatment for depression
• Venlafaxine (Effexor XR), a treatment for depression
• Levothyroxine (Synthroid, Levoxyl), a drug given to people whose thyroid glands don't work properly
• Unprescribed or illegal stimulants, such as methamphetamine and cocaine

How is broken heart syndrome different from a heart attack?

Heart attacks are generally caused by a complete or near complete blockage of a heart artery. This blockage is due to a blood clot forming at the site of narrowing from fatty buildup (atherosclerosis) in the wall of the artery. In broken heart syndrome, the heart arteries are not blocked, although blood flow in the arteries of the heart may be reduced.