The cause of broken heart syndrome isn’t fully known. However, extreme emotional or physical stress is believed to play a role in causing the temporary disorder.
Although symptoms are similar to those of a heart attack, what is happening to the heart is quite different. Most heart attacks are caused by near or complete blockage of a coronary artery. In broken heart syndrome, the coronary arteries are not blocked, although blood flow may be reduced.
In most cases, broken heart syndrome occurs after an intense and upsetting emotional or physical event. Some potential triggers of broken heart syndrome are:
- Emotional stressors—extreme grief, fear, or anger, for example as a result of the unexpected death of a loved one, financial or legal trouble, intense fear, domestic abuse, confrontational argument, car accident, public speaking, or even a surprise party.
- Physical stressors—an asthma attack, serious illness or surgery, or exhausting physical effort.
Researchers think that sudden stress releases hormones that overwhelm or “stun” the heart. (The term “stunned” is often used to indicate that the injury to the heart muscle is only temporary.) This can trigger changes in heart muscle cells or coronary blood vessels, or both. The heart becomes so weak that its left ventricle (which is the chamber that pumps blood from your heart to your body) bulges and cannot pump well, while the other parts of the heart work normally or with even more forceful contractions. As a result the heart is unable to pump properly. (For more information about the heart’s pumping action and blood flow, go to the Health Topics How the Heart Works article.)
Researchers are trying to identify the precise way in which the stress hormones affect the heart. Broken heart syndrome may result from a hormone surge, coronary artery spasm, or microvascular dysfunction.
Intense stress causes large amounts of the “fight or flight” hormones, such as adrenaline and noradrenaline, to be released into your bloodstream. The hormones are meant to help you cope with the stress. Researchers think that the sudden surge of hormones overwhelms and stuns the heart muscle, producing symptoms similar to those of a heart attack.
Coronary Artery Spasm
Some research suggests that the extreme stress causes a temporary, sudden narrowing of one of the coronary arteries as a result of a spasm. The spasm slows or stops blood flow through the artery and starves part of the heart of oxygen-rich blood.
Another theory that is gaining traction is that the very small coronary arteries (called microvascular arteries) do not function well due to low hormone levels occurring before or after menopause. The microvascular arteries fail to provide enough oxygen-rich blood to the heart muscle.