What happens to the heart when we love?

Dr Simon Andreas Müggler, from a cultural and historical perspective, the heart has always been more than just a muscle that pumps blood. As a specialist in cardiology, do you agree?

I absolutely agree. Of course, the heart can be seen purely as a "pump", a specialised muscular organ that maintains blood circulation and thus the supply of oxygen to the organs. However, the fact that many people pay more attention to the heart than other organs is based on several factors: A failure of cardiac function lasting even a few seconds quickly leads to unconsciousness and irreparable damage, for example to the brain, occurs after just a few minutes if cardiac function is not immediately restored or replaced by cardiac massage ("resuscitation") or technical measures ("heart-lung machine"). The heart is thus seen as a symbol of life like no other organ. For thousands of years, people have also regarded the heart as the seat of the "soul" and as a symbol of love. The heart is strongly associated with emotions, and expressions such as "a heartless person", "it breaks my heart", "heartfelt greetings" or "taking something to heart" still bear witness to this in our language today.

There is a close connection between the heart and the brain, between our feelings and our emotions. To what extent is it true to assume that love, partnership and satisfying social relationships are also good for the heart in a medical sense?

This assumption is absolutely correct. There are many reasons for this and several studies that have shown the positive effects of love, an intact partnership and positive social relationships. Love lowers stress levels and leads to the release of happiness hormones, which tends to prevent people from engaging in self-harming behaviour such as smoking, excessive alcohol consumption, unhealthy eating or lack of exercise. People in an intact relationship also have lower blood pressure levels, which has a positive effect on long-term heart health. A large US study showed that married people live longer compared to widowed, divorced or unmarried people. It is also known that people who live in a partnership in which they receive little support from their partner have a higher risk of developing arteriosclerosis. Arteriosclerosis (hardening of the arteries) can then lead to a heart attack. Love in the sense of sexual activity is also good for the heart: both women and men with regular sexual activity have a lower risk of a heart attack. Sex can be seen as a form of endurance training with positive effects for the heart in terms of fitness, blood pressure and stress levels.

The heart is known to be equipped with around 40,000 nerve cells. What about heartbreak: is the heart muscle directly affected when "the heart breaks"?

In most cases, the heart survives heartbreak unscathed. However, the "broken heart" really does exist: it has been known for a good 30 years that acute, extraordinary emotional stress, including heartbreak, can lead to a functional disorder of the heart muscle and heart failure. This clinical picture (Takotsubo syndrome, stress cardiomyopathy) is also known as "broken heart syndrome". The exact mechanism of this disease is still the subject of research, but a connection with the body's own stress hormones adrenaline and noradrenaline probably plays a decisive role. Broken heart syndrome can present like a heart attack with chest pain or shortness of breath, so that further investigations and treatment must be carried out immediately. Fortunately, the prognosis for broken heart syndrome is generally good, with most patients making a full recovery within a few weeks. Incidentally, women are significantly more frequently affected by broken heart syndrome than men.

Interestingly, it is not only negative emotions that can trigger stress-related heart problems. It is said that there is also a "happy heart syndrome". Is this true and what is it all about?

Strong positive emotions, such as a wedding, the birth of a grandchild or a surprise birthday party, can also trigger stress cardiomyopathy, probably according to the same mechanism as "broken heart syndrome" (Takotsubo syndrome). Apparently, despite their different character, both sad and happy life events can have similar emotional effects, which can lead to "broken heart syndrome" (in the case of negative emotional exceptional situations) or "happy heart syndrome" (in the case of positive emotional exceptional situations). How and whether Takotsubo syndrome can be prevented is still unknown. However, the risk of developing it a second time after the first occurrence is increased. Nevertheless, people affected should try to enjoy life and not be constantly afraid of contracting the disease a second time. This would lead to chronic stress, which in turn would be bad for the heart.