It's like having your own personal coronary care unit

Dr Arthur Moss

Researchers from the University of Rochester Medical Center in the US have found that one way to minimise the risk is to insert an implantable defibrillator.

The device works in the same way as an external defibrillator - it delivers an electric shock to restore the heart's normal function.

A study of 1,232 patients found that it reduced the death rate by 31%.

Major advance

Lead researcher Dr Arthur Moss, of the University of Rochester Medical Center, said: "It's like having your own personal coronary care unit.

"No other single therapy for this population has been shown to reduce mortality by nearly one-third.

"The last breakthrough of this magnitude was the introduction of beta-blockers in the 1970s."

The device, known fully as the implantable cardioverter defibrillator (ICD), is the size of a pager and is surgically implanted in the chest under a local anaesthetic.

It detects irregular and potentially fatal heartbeats and shocks the heart back into a normal rhythm.

It was originally introduced about 20 years ago, but was only prescribed to small numbers of patients.

But recent improvements mean that it can now benefit many more patients. Among those who have had a ICD fitted is US Deputy President Dick Cheney.

Mysterious condition

Sudden death from cardiac arrest is less understood than other forms of heart disease.

It occurs most often in men in their 60s, when the heart stops abruptly, usually as a result of an electrical malfunction due to rapid and chaotic rhythms from blockage of coronary arteries or scarring from a prior heart attack.

Young adults with heart disease are also prone to unexpected cardiac arrest, when an adrenaline surge during intense physical activity sets off an irregular heart beat. Certain drugs can also trigger abnormal rhythms and death.

The research was presented at a meeting of the American College of Cardiology. It is also published in the New England Journal of Medicine.