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Scientists have shown for the first time that the brain is
involved in the development of Takotsubo syndrome (TTS) also known as “broken
heart syndrome”. They found that regions of the brain responsible for
processing emotions and controlling the unconscious workings of the body, such
as heart beat, breathing and digestion, do not communicate with each other as
well in TTS patients as in healthy people.

The study is published in the European Heart Journal and
the researchers say that although, at this stage, they cannot show that the
reduced brain functions definitely cause TTS, their findings suggest that these
alterations in the central nervous system may be part of the mechanism involved
and they are linked with the onset of TTS in response to stressful or emotional
triggers.

TTS is characterised by a sudden temporary weakening of the
heart muscles that causes the left ventricle of the heart to balloon out at the
bottom while the neck remains narrow, creating a shape resembling a Japanese
octopus trap, from which it gets its name. Since this relatively rare condition
was first described in 1990, evidence has suggested that it is typically
triggered by episodes of severe emotional distress, such as grief, anger or
fear, or reactions to happy or joyful events. Patients develop chest pains and
breathlessness, and it can lead to heart attacks and death. TTS is more common
in women with only 10% of cases occurring in men.

In an unusual example of collaboration between
neuroscientists and cardiologists, researchers carried out MRI brain scans in
15 TTS patients taken from the InterTAK Registry, established at the University
Hospital Zurich, Switzerland, in 2011. They compared the scans with those from
39 healthy people. The scans were performed between July 2013 and July 2014 and
the average time between TTS diagnosis and the MRI scans was about a year.

Prof Christian Templin, principle investigator at the
Registry and professor of cardiology at University Hospital Zurich, said: “We
were interested in four specific brain regions that are spatially separate from
one another but functionally connected, meaning they share information. We
found that TTS patients had decreased communication between brain regions associated
with emotional processing and the autonomic nervous system, which controls the
unconscious workings of the body, compared to the healthy people.

“For the first time, we have identified a correlation
between alterations to the functional activity of specific brain regions and
TTS, which strongly supports the idea that the brain is involved in the
underlying mechanism of TTS. Emotional and physical stress are strongly
associated with TTS, and it has been hypothesised that the overstimulation of the
autonomic nervous system may lead to TTS events.”

The regions of the brain that the researchers looked at
included the amygdala, hippocampus and cingulate gyrus, which control emotions,
motivation, learning and memory. The amygdala and cingulate gyrus are also
involved in the control of the autonomic nervous system and regulating heart
function. In addition, the cingulate gyrus is involved in depression and other
mood disorders that are common among TTS patients.

“Importantly, the regions we’ve identified as communicating
less with one another in TTS patients are the same brain regions that are
thought to control our response to stress. Therefore, this decrease in
communication could negatively affect the way patients respond to stress and
make them more susceptible to developing TTS,” said Prof Templin.

A limitation of the study is that the researchers did not
have MRI scans of patients’ brains before or at the time they developed TTS, so
cannot say for certain that the decreased communication between brain regions
caused the TTS or vice versa.

Co-author, Dr Jelena Ghadri, a senior research associate at
the University Hospital Zurich and co-principle investigator of the InterTAK
Registry, said: “Our results suggest that additional studies should be conducted
to determine whether this is a causal relationship. We hope this study offers
new starting points for studying TTS in terms of understanding that it much
more than ‘broken heart’ syndrome and clearly involves interactions between the
brain and the heart, which are still not fully understood. We are at the
beginning of learning more about this complex disorder. Hopefully, one day new
findings can be translated into developments in preventive, therapeutic and
diagnostic strategies to improve patient care.

“Of note, this study presents the results of a collaboration
between neuroscientists and cardiologists. One problem in TTS research is that
usually cardiologists only focus on the heart; we believe that approaching TTS
in a multidisciplinary way might help to uncover the real nature and causes of
this disease. The methods we used are mainly neuroscientific in nature, but the
findings we uncovered are, in our view, of major importance for cardiologists
in understanding TTS.”

Source: https://www.escardio.org/The-ESC/Press-Office/Press-releases/Broken-heart-syndrome-may-originate-in-the-brain

Reference: Templin
C, et al. Altered limbic and autonomic processing supports brain-heart axis in
Takotsubo syndrome. European Heart Journal. Published 5 March 2019. https://academic.oup.com/eurheartj/advance-article/doi/10.1093/eurheartj/ehz068/5366976