On a winter morning in 1995 during one of the worst snow blizzards New York had seen in years, a Merrill Lynch trader dug out his car and drove to work. No sooner had he arrived on the floor of the New York Stock Exchange than he collapsed with a heart attack and died.

Some believe his death could have been avoided if the NYSE had been equipped with a defibrillator and hand-held electrocardiogram monitor, a device that produces an electric shock to restore the heart to its natural rhythm. Contained in a box about the size of a hard cover book, the portable defibrillator contains small pads that are taped to the patient and a computer that administers treatment.

When the machine is turned on, it gives a series of voice instructions to the user to attach the pads to the victim's chest and then stand back. The defibrillator analyses the heart's rhythm and determines whether the heart is in distress. If so, it charges up and instructs the rescuer to push a red button that delivers a shock. From arrival at the scene to administering the first shock to the victim should take from between 15 to 30 seconds. The device makes the decision on whether a second or third shock is necessary.

A broker on the trading floor, Al Harmon, was luckier. Four years ago, at the age of 50, he thought he was having heart burn and went up the medical room on the ninth floor. There the nurse hooked him up and told him he was having a heart attack. "We didn't have a defibrillator then," said Mr Harmon. "Mine was mild. I had a blockage that I got taken care of."

The trading floor on Wall Street has 5,000 workers who are largely middle-aged men suffering from poor diet, lack of exercise and stressful jobs. The heart attack rate at the exchange is 60 per cent higher than the national rate for men between the ages of 18 and 65. On whether the installation of a defibrillator is a good idea, Mr Harmon said: "I would imagine any place with a large number of people should have one. They are life savers and you don't need expertise in operating them."

The NYSE has since installed four. Other industries, most notably airlines, have followed suit. American Airlines was the first airline in the US to decide to equip all its 649 aircraft with defibrillators by this November and by the year 2000 Delta will equip its entire fleet of 558 aircraft with automatic external defibrillators (AED).

During 1996, the US Air Transport Association counted 141 heart attacks and 433 cases of passengers complaining of chest pains on board flights. The study also found that 557 emergency landings were made for medical reasons, of which about a third were for cardiovascular problems.

"Any place where it's hard for an emergency crew to get to the victim in time is an ideal place to install a defibrillator," said Wendy Stross, a spokeswoman for HP Heartstream Inc., a Seattle, Washington-based company that manufactures ForeRunner, the battery-powered device that has been adopted by the airlines.

Crowded places such as factories, office buildings, stadiums, health clubs, casinos and cinemas could also benefit by having defibrillators as accessible as fire extinguishers. The American Heart Association estimates that by having defibrillators more widely deployed, as many as 100,000 unnecessary deaths could be prevented each year. Some 1,000 times a day someone suffers a heart attack in the US. That amounts to about 1.5 million people each year, killing about a third of them. Every minute before defibrillation reduces the chance of survival by about 10 per cent. Time is the enemy.

Although Heartstream has been around since 1993, it was bought by Hewlett-Packard in March of this year and became part of H-P's Medical Products Group. There are three other manufacturers in the US: Physio-Control International Corp. of Redmond, Washington; Survivalink Corp. of Minneapolis, Minnesota; and Laerdal Medical Corp., a Norwegian company with US headquarters in Wappingers Falls, New York.

Over the years the devices have become less complicated to use and more portable. They each weigh about five pounds and sell for between $3,000 and $4,000. They are increasingly being adopted by police officers, security guards and fire department personnel because they require little training and are low on maintenance.

Physio-Control pioneered portable defibrillation technology 30 years ago and its product line is the LifePak defibrillator/monitor series. It has 40 per cent of the international marketplace and 80 per cent of the US market. Last year, the company shipped 10,000 of its LifePak 500 AED devices.

"Certainly the US is the leader in implementing emergency response systems," said Doug Hakala, Physio-Control's business development manager for corporate and commercial accounts. "In some parts of the world, there still needs to be a physician present."

Although Physio-Control's main markets are hospitals and the emergency medical services, "the commercial marketplace is very large in scope", said Mr Hakala.

"Typically, training takes four hours for an individual dependent on a medical director's specifications," he said. "Hundreds of thousands of lives could be saved if only we had automated defibrillators in the hands of individuals who would be there early," said Mr Hakala.

In case you're wondering, the best place in the US to have a heart attack (if there is such a thing!), is Rochester, Minnesota, which has a survival rate of 49 per cent. Mr Hakala puts this down to it being the home of the world-famous Mayo Clinic. Furthermore, all police cars in the city carry defibrillators.