What should you do - and what should you not do - if you are having a heart attack? Would you recognise the symptoms of a heart attack? And what do you do if a colleague at work or a family member suffers a heart attack - and their life is in your hands?

Some 14,000 people die in Ireland each year due to coronary heart disease, stroke and other diseases of the circulation. Many of these fatalities occur suddenly from a heart attack. Up to two thirds of people who die of a heart attack do so outside of hospital. They are usually dead within two hours of the first symptoms of the heart attack.

Up to 25 per cent of people having a heart attack feel no pain whatsoever or they experience only mild discomfort. They might put it down to indigestion.

Older people having a heart attack might feel only a sudden tiredness or breathlessness. Others feel a sudden and severe pain in the chest. Some describe it as a vice-like grip or pressure, crushing and compressing the chest. It can start at the breastbone and extend to an arm, both arms - or to the neck, jaw, stomach or back. The pain can last half an hour or for a number of hours. If you are having a heart attack, you may find it difficult to breathe. You could sweat profusely, feel anxious, irritable or be unable to concentrate. You could feel dizzy or that you're about to get sick; or you may actually faint or vomit.

But you won't necessarily experience all of these symptoms. It is easy to dismiss a heart attack as something less serious. This can be a fatal mistake because in up to 60 per cent of cases, the heart stops beating - you suffer a cardiac arrest - within an hour or two of the heart attack.

Unless you are in hospital, in a cardiac ambulance or in the presence of someone who can perform CPR (cardiopulmonary resuscitation), you will almost certainly die. That's why it is so critical to recognise the symptoms and get help immediately. If you're not certain, it is usually better to assume it is a heart attack and act accordingly than dismiss it and hope for the best.

A common problem is convincing a person having a heart attack that they are actually having one. Famous last words include: "Bit of indigestion, I'll be fine"; "Don't be ridiculous. I'm too young to have a heart attack"; "Let's not be alarmist - mustn't frighten the hubby"; or "Look, I'll visit the doctor tomorrow".

If you think someone is having a heart attack - regardless of what they say - call 999 or 112 and be sure to ask for a cardiac ambulance. Give the controller your phone number, your precise location and any landmarks to help the ambulance to get there without delay. Don't hang up until the controller is satisfied he has all the necessary information.

If you are having the heart attack, get someone else to make that vital phone call. If the ambulance could take some time - for instance, if you're calling from a rural location - get them to call the nearest doctor too. If you suffer a cardiac arrest, the doctor will be able to administer medication and perform CPR. (CPR ensures that blood and oxygen continues to flow when the heart has stopped beating.)

People having a heart attack often do precisely the opposite to what they should do. For instance, they drive or walk to the hospital. Or they go for a walk to see if that will make them feel better. If you think you might be having a heart attack, you should stop all activity immediately. Complete rest is essential. Any physical activity can exacerbate the damage to the heart muscle.

You should lie in a position you find comfortable, usually a half-seated position (such as the position while lying on a stretcher), with head and shoulders raised. (If the person is unconscious, lie them down on their side.) Have someone loosen your clothes at the neck, chest and waist. If possible, try not to panic because anxiety and fear can release adrenalin into the system which could compound the damage to the heart.

The Irish Heart Foundation has trained more than 1,200 CPR instructors in Ireland, who in turn have trained in excess of 28,000 members of the public. It aims to provide CPR training to 10 per cent of the adult population by 2000. If you are interested in learning CPR life-saving skills, contact the Resuscitation Department, Irish Heart Foundation, 4 Clyde Road, Ballsbridge, Dublin 4. Telephone: 01 668 5001.