We’re all familiar with the idea of a broken heart, used to describe the emotional and sometimes physical pain of losing a loved one. It’s not uncommon to hear a broken heart blamed when someone dies not long after a much-loved partner.
But it wasn’t until recently that heart doctors identified a new heart condition that may shed some new light on these more anecdotal tales. Because it’s usually triggered by a severely stressful event, such as discovering the death of a loved one, it has become known as broken heart syndrome in the context of bereavement. But in medical circles we know it as Takotsubo Cardiomyopathy.
Over the past 20 years there has been a revolution in how we treat heart attacks. In the developed world, the vast majority of people arriving in A&E with severe cardiac chest pain (angina) and the changes to their heart tracing (the ECG that we’re all now used to seeing on heart monitors on TV and in the news) that suggest a heart attack, are fast tracked to a special unit.
Here doctors take angiograms, by tracing the movement of liquid injected into the heart to find the blocked coronary artery that normally causes a regular heart attack.
Something different about Takotsubo
But sometimes someone arrives at the hospital who seems to be having a regular heart attack but isn’t. They have chest pains, a shortness of breath and ECG monitors show the same extreme changes which we see with a heart attack.
But when an angiogram is performed, none of their coronary arteries are blocked. Instead, the lower half of their ventricle, the main pumping chamber of their heart, shows a very peculiar and distinctive abnormality - it fails to contract, and appears partially or completely paralysed.
The top half carries on beating normally or even more aggressively than usual to compensate for the paralysed lower half. When a picture of the heart is taken, it resembles a vase with a narrow neck and bulbous lower half. It was initially recognised in Japan in earthquake survivors (a major stress!), and named after the Japanese fishermen’s octopus traps that resemble the problem heart. Before Takotsubo was identified these patients were treated as if they were having a heart attack.
In severe cases, people need to be admitted to hospital, have appropriate monitoring and given intensive treatment. In the most extreme cases the heart can stop - a cardiac arrest. But with treatment and in milder cases, the heart amazingly recovers, which doesn’t happen with heart attacks. Several weeks or months later and you can be back to normal, with no scarring of the heart muscle, which you get with true heart attacks.
We don’t currently know how common cardiomyopathy is in society. Observations from various hospitals around the world have consistently reported a figure of about 2% of all people who show up looking like they are having a heart attack.
As a guide, and a back of the envelope calculation, this suggests that in the UK some 3000 to 4000 people suffer from Takotsubo every year.
Intriguingly, more than 90% of people who experience this condition are middle-aged or elderly women, all postmenopausal. It is not clear whether they are the survivors, and men drop dead suddenly with severe stress, or whether the postmenopausal female heart is more sensitive to adrenaline.
Adrenaline looks a likely culprit
To paraphrase Donald Rumsfeld, there are many known unknowns when it comes to broken heart syndrome but we’re learning much more about this fascinating condition and why the heart undergoes this temporary paralysis in just one area. We suspect it’s triggered by adrenaline, one of the body’s main stress hormones, often associated with fight or flight response.
In some cases, we’ve seen Takotsubo cadiomyopathy triggered by adrenaline injections, either in medical emergencies, which are in themselves stressful, or in accidents. Research from our lab at Imperial College London would also support a central role for adrenaline.
At low and medium levels adrenaline is a stimulating hormone, triggering the heart to beat harder and faster, which we need during exercise or stress. However at the highest levels it has the opposite effect and can reduce the power the heart has to beat and triggering temporary heart muscle paralysis.
We believe this is actually a protective response to prevent excessive stimulation to the heart muscle. Paradoxically, by triggering the paralysis, this may protect the heart from extreme severe stress. Most people recover from the acute Takotsubo episode, and although the initial phase can be high risk, the long-term outlook for sufferers is very good. A few people have recurrent episodes, and in rare cases it can run in families.
We successfully campaigned to have Takotsubo Cardiomyopathy added to the list of data collected by the UK national audit of heart attacks so we will have a better idea of the actual numbers over the next few years. There are currently no guidelines for how to treat Takotsubo in the UK, so cardiac tests and treatment is highly variable. The Royal Brompton Hospital also now has a service to understand more about it and the people who suffer from this condition.
We might also learn more about how stress affects the heart in general.