Can happiness break your heart?

"Moments of joy 'can damage heart'," reports BBC News.

That's the finding of a study carried out to assess whether Takotsubo syndrome (TTS) – where negative emotional events, such as grief, cause the chambers of the heart to balloon – can also be triggered by positive emotional events, such as a wedding or a birthday party.

In TTS the heart muscle becomes weakened after a sad event, leading to the syndrome also being termed "broken heart syndrome". The researchers seem to suggest it could also be called "happy heart syndrome", if following a positive event.

The study analysed data from 1,750 people with TTS and identified 485 cases which had a definite emotional trigger. Although the vast majority of these events were negative, 20 patients (4.1%) developed the syndrome after a positive event. 

The reliability of these findings is limited by the comparatively small number of people experiencing TTS after a positive event. Also, the study population was mainly female older adults so we cannot be certain the same results would be seen in other groups.

The main finding here is the possibility that positive events can cause TTS in some people, though we do not know how or why this might happen.

This should not be taken as a reason not to enjoy positive emotional events, TTS is rare and its effects are usually reversible, so there is no real need for concern.

Where did the story come from?

The study was carried out by researchers from a number of institutions, including University Hospital Zurich and the University of Southern California. 

Funding was provided by Mach-Gaensslen Foundation, Olten Heart Foundation, Prof. Otto-Beisheim-Foundation, and Swiss Heart Foundation.

The study was published in the peer-reviewed European Heart Journal.

The reporting in the UK media was largely accurate with a number of quotes from the study authors and experts in the field.

The BBC provided the opinion of Professor Peter Weissberg, medical director at the British Heart Foundation, he said: "Takotsubo syndrome is a rare event. This study suggests that in a very few cases, the triggering event may be a happy one. 

"Much more research is needed to understand how such emotional events can trigger temporary heart damage in a few susceptible individuals."

However, The Sun's headline that "too much happiness can kill you," was not an accurate reflection of the study findings. None of the people with a positive event prior to TTS died, and only 1% of people with TTS after a negative event died.

What kind of research was this?

This was a data analysis study which looked at the International Takotsubo Registry to analyse the prevalence and characteristics of Takotsubo syndrome (TTS) following pleasant events, rather than the negative events usually believed to trigger the condition.

TTS is where the heart muscle is weakened, causing the heart chambers to balloon; this is thought to be due to a surge of hormones during a period of stress. The condition is temporary and usually reversible.

What did the research involve?

The researchers used data from the International Takotsubo Registry, which collects data from people with TTS from the leading hospital in Zurich and 25 collaborating centres around Europe, including the UK.

The researchers established how many of those had a clearly identifiable emotional event before developing TTS. They split this group into those occurring after pleasant events, the "happy hearts" group, or negative emotional events, the "broken hearts" group.

The participant's medical records were analysed to look for the following: 

• how the symptoms of TTS developed
• any risk factors or markers for heart disease
• the findings of electrocardiographic (ECG) testing
• any medications they were already taking
• other factors such as age, sex and body mass index (BMI)

Follow-up information was obtained through telephone interviews, clinical visits or medical records.

What were the basic results?

There were 1,750 people included in the study, 485 of which developed TTS following an emotional event. Pleasant emotional events were thought to be responsible for 20 of these cases (4.1%) and negative emotional events for the remainder (95.9%).

Events thought to be responsible for happy heart syndrome included:

• a birthday party
• meeting old friends
• family parties
• a positive job interview
• weddings
• favourite driver winning a car race

Events thought to be responsible for broken heart syndrome included:

• the death of a spouse or other close family member
• an accident such as a car crash
• a burglary
• being arrested
• divorce
• house damaged by fire or flood

People presenting clinically with "happy heart syndrome" and "broken heart syndrome" had similar symptoms, including chest pain and shortness of breath. Other findings were similar between groups.

How did the researchers interpret the results?

The researchers concluded that their study illustrated that, "TTS can be triggered by not only negative but also positive life events.

"Presumably, despite their distinct nature, happy and sad life events may share similar final common emotional pathways, which can ultimately trigger TTS."

Conclusion

This study aimed to assess whether Takotsubo syndrome – which often occurs after negative emotional events leading to "broken heart syndrome" – can also occur after a positive emotional event.

The researchers used data from 1,750 people with TTS and found 485 cases preceded by an emotional event, 20 of which were positive emotional events, leading to the use of the term "happy heart syndrome". These events ranged from family parties to weddings. 

The limitations of this study are that the number of people experiencing TTS after a positive event is very small, so we can only establish themes for further research. Also, the study population was mainly female older adults, so we cannot be certain the same findings would be seen in other groups.

The main finding here is the possibility that positive events can cause TTS in some people; however, we do not know how or why this might happen. Indeed, although it is thought that emotional events trigger TTS, this has not been proven and many of the 1,750 cases did not have any preceding physical or emotional event. Further research is needed in this area.

These findings should not be taken as a reason to not enjoy positive emotional events. TTS is rare and usually reversible, so there is no real need for concern.