Heart attack alarm 'will save lives' For every 30 minutes that you wait, because you don't know you're having a heart attack, your deth rate increases by 7.5 per cent. This device is designed to cut that time and possibly save 25 to 30 per cent more lives. About the size of an old-style pager, it is implanted just under the skin below the collar bone. It can alert the wearer to a potentially serious problem, in which case they should see a doctor in 48 hours, or that an attack is just about to happen, in which case they should get straight to hospital. It can also be made to either beep or vibrate, depending on preference, like a mobile phone. Small scale trials in people are now underway in the US. It has received CE mark approval for sale in Europe, but is not currently available on the NHS. It is likely to cost at least £10,000. Due to expense and the fact surgery is needed to implant it, they are likely to be reserved for those who have either already had a heart attack or are judged to be at extremely high risk of a first one. About 100,000 people have a heart attack in England every year, of whom about one in eight die within 30 days. However, the British Heart Foundation estimates there are about 1.5 million people living in Britain who have suffered heart attacks.