Scientists revealed there may be warning signs for sudden cardiac arrest

Cardiac arrest stops the heart abruptly - and kills 350,000 in US each year

Doctors had thought that condition was sudden and unpredictable

But study found people can have shortness of breath and chest pain before

Half of people ignore symptoms - hours, days and weeks before collapse

The clue is the name - sudden cardiac arrest.

The heart suddenly and unexpectedly stops beating. Blood stops flowing to the brain and other vital organs, and without treatment, within minutes a person is typically dead.

But, a new study has suggested it is not as sudden as first thought.

Half of sufferers experience warning signs hours, days, sometimes even weeks before cardiac arrest strikes, doctors at Cedars-Sinai Heart Institute in Los Angeles discovered.

However, most people ignore those symptoms – and miss a chance to save their own lives, according to the study.

Study leader Dr Sumeet Chugh said: ‘By the time the 911 call is made, it’s much too late for at least 90 per cent of people.

‘There’s this window of opportunity that we didn’t really know existed.’

Cardiac arrest causes the heart to stop abruptly after its electrical system is knocked out of rhythm. It kills 350,000 people in the US each year. Previous research suggested cardiac arrest was unpredictable, but scientists revealed its sufferers exhibit warning signs beforehand - which half of sufferers ignore