Scientists are one step closer to working out why some people die of a broken heart, with the combination of long-term stress and experiencing a stressful event thought to trigger a condition known as broken heart syndrome.
Also known as takotsubo syndrome, broken heart syndrome has symptoms similar to those of a heart attack and can include chest pain and shortness of breath.
The syndrome can cause a range of complications and is thought to affect around 2,500 people in the UK each year. Those affected are mainly post-menopausal women and, in some cases, the syndrome can be fatal.
New research funded by the British Heart Foundation (BHF) and published in the journal Cardiovascular Research has found that two molecules linked to increased stress levels play a key role in the development of the syndrome.
Experts from Imperial College London found that increased levels of microRNAs -16 and -26a (small molecules that regulate how genes are decoded) increase the chance of suffering the syndrome.
During lab work, the researchers examined human and rat heart cells and measured how they responded to adrenaline after exposure to the two molecules.
When researchers looked at heart cells that had been treated with the microRNAs, they saw that the cells were more sensitive to adrenaline and more likely to develop loss of contraction.
Changes linked to broken heart syndrome were therefore seen at lower levels of adrenaline.
MicroRNAs -16 and -26a are linked to depression, anxiety and increased stress levels, suggesting that longer-term stress followed by a dramatic shock could trigger the effects seen in broken heart syndrome.
Experts hope a blood test or drugs may now be developed in the future in response to the findings.
Sian Harding, professor of cardiac pharmacology at Imperial College London, said: “Takotsubo syndrome is a serious condition, but until now the way it occurs has remained a mystery.
“We don’t understand why some people respond in this way to a sudden emotional shock while many do not.
“This study confirms that prior stress, and the microRNAs associated with it, can predispose a person to developing takotsubo syndrome in situations of future stress.
“Stress comes in many forms and we need further research to understand these chronic stress processes.”
Professor Metin Avkiran, associate medical director at the British Heart Foundation, said: “Takotsubo syndrome is a sudden and potentially catastrophic heart problem but our knowledge about what causes it remains limited.
“As such, it is vital that we learn more about this neglected condition and develop new ways of preventing and treating it.
“This research is not only a crucial step towards better understanding of this mysterious disease but also could provide new ways to identify and treat those at risk of takotsubo.
“We now need further research to determine if drugs that block these microRNAs could be the key to avoiding broken hearts.”
Broken heart syndrome often occurs following a particularly intense event. This could include the death of a loved one, a life-threatening medical diagnosis, losing a lot of money, a redundancy or the end of a relationship.
Currently, there exist no treatments to prevent a repeat attack of the syndrome.
Additional reporting by PARead More