Because more than 90 per cent of people who collapse without warning are likely to die, some governmental authorities are urging their citizens to learn cardiopulmonary resuscitation (CPR).

The initiative recognises that defibrillation equipment is unlikely to be readily available – because 85 per cent of cardiac arrests occur in the home – and that CPR often is the only immediate treatment if someone is down and not breathing.

During the crucial few minutes before professional help arrives, the brain and heart can suffer irreversible damage unless CPR is started.

Even chest compression alone can make a vital difference, doctors say.