More than 1,000 people a year, many young women, are falling victim to stress-related heart attacks, new resarch suggests.
The British study shows that the condition - which is unusual because it mainly occurs in those without obvious risks of heart disease - is causing hundreds of hospitalisations each year, with at least 100 deaths.
Researchers said women were most at risk from the condition, which has been linked to emotional stress caused by events such as death in the famiily as well as the exertion of extreme exercise, pregnancy or labour.
While the average age of victims was found to be 52, around 30 per cent of cases involved women who were nearing the end of a pregnancy or had recently given birth.
The research, carried out by cardiologists at Aston Medical School, Aston University in Birmingham, UK and the University of Alberta, Edmonton, Canada is the first major study to establish incidence of Spontaneous Coronary Artery Dissection, or SCAD.
The findings, presented to the annual scientific session of the American College of Cardiologists in Washington DC, come from a study of more than 33,000 heart attack victims.
After tracking cases over a period of 15 years, researchers found 0.54 per cent were due to SCAD.
With over 188,000 heart attacks each year in the UK, this means approximately 1,000 may be due to the condition.
In total, 10.4 per cent of SCAD victims died from the condition – equating to around 100 deaths a year in the UK.
The condition occurs when one or more of the inner layers of a coronary artery tears away from the outer layer. Blood is able to flow into the space between the layers and a blood clot forms, reducing the flow through the artery, leading in some cases to a potentially fatal heart attack.
The study showed sufferers were very different to those at risk of more common forms of heart attack.
The average age of SCAD victims was just 52, compared to 66 for other heart attack sufferers.
And the research found they were far less likely to suffer from known factors for heart disease - such as diabetes, high cholesterol levels or high blood pressure – making them much harder to identify.
Dr Rahul Potluri, lead researcher from Aston University said: “SCAD is unusual because, unlike other heart attacks where the coronary arteries get plugged up over time with cholesterol deposits, it’s caused by a sudden tear where the coronary artery simply falls apart.
“It’s also seen in a much different group of people – typically young women, many of them either pregnant or shortly after giving birth. We believe that emotional and hormonal factors play a big part in SCAD attacks, although the exact cause will vary from person to person.”
The cardiology lecturer, who founded the Algorithm for Comorbidities, Associations, Length of stay and Mortality Study Unit at Aston University, said the data had enabled them to establish incidence of the condition, and identify risk factors for it. However, he said he believed cases were still significantly under-reported, with cases missed or mistaken for more conventional forms of heart attacks.
Dr David Adlam, Senior Lecturer in Acute and Interventional Cardiology at the University of Leicester, said more research was needed to increase understanding of the devastating condition, and highlighted an ongoing study funded by the British Heart Foundation.
"Predominantly, these patients are young, healthy women whom all of a sudden are stricken with a heart attack. We owe it to our patients to give them answers, so they can move forward with their lives," he said.
Earlier this month, research by Imperial College London suggested that doctors could be missing warning signs of heart attacks in up to one in six fatal cases.
Classic symptoms of a heart attack include sudden chest pain or a "crushing" sensation that may spread down either arm.
But researchers said doctors could be missing “subtle signs” of illness - such as fainting and shortness of breath - which could indicate an increased risk of suffering a heart attack.
The study examined the hospital records of almost 450,000 NHS hospital stays involving heart attacks between 2006 and 2010, as well as the history of all 135,950 heart attack deaths in England over the four years.
Of the fatal heart attack victims studied, 21,677 - one in six of the total - had been admitted to hospital up to four weeks before their death. Yet no mention of heart attack symptoms was made in their hospital records.
Symptoms such as fainting, shortness of breath and chest pain would have been evident up to a month before death in some of these patients, the researchers said.