A shortage of defibrillators - which shock the heart - and a lack of public awareness could be costing thousands of lives every year, research suggests.
Experts found that fewer than 2% of heart attack victims in one county in England were treated with the device before an ambulance arrived - a figure described as "disappointingly low".
The British Heart Foundation (BMF) estimates that 60,000 heart attacks occur out of hospital every year across the UK.
Research has shown that when somebody is having a heart attack leading to unconsciousness, every minute of delay in resuscitation and defibrillation reduces their chance of survival by 10%.
A defibrillator is a machine that delivers an electric shock to the heart when someone is having a heart attack, is unconscious and not breathing. It is designed to be used by anyone, including members of the public.
Once the defibrillator box is opened, a recorded voice gives instructions on where to place pads on a person's chest.
People then simply press a large button to start electrical shocks to the person's heart. The defibrillator will not work unless the person is having a heart attack - meaning people cannot make the situation "worse" by using one.
Today's study, published online in the journal Heart, examined use of the devices in one county - Hampshire.
Hampshire was chosen because it has a mix of rural and urban settings, covers an area of 1,400 square miles, and has a population of around 1.76 million, 12% of whom are aged over 70.
The authors, including from the South Central Ambulance Service and the University of Southampton, reviewed all calls made to the South Central Ambulance Service between September 2011 and August 2012 following a heart attack.
For all emergency calls made from locations other than a person's home, the call handler specifically asks whether the caller can access a defibrillator. If so, instructions are given in how to use it.
During the course of the study, the service received 1,035 calls about confirmed cardiac arrests away from a hospital - the equivalent of one for every 600 members of the public each year.
For 44 of these incidents (4.25%), in 34 different locations, the caller was able to access an external defibrillator. However, it was successfully retrieved and used in less than half the cases (18 cases) before the arrival of an ambulance.
This gave an overall use rate of just 1.74% of all cardiac arrests recorded, which the authors said was "disappointingly low" and similar to previous figures from the London Ambulance Service.
Across Hampshire, 673 defibrillators that could be accessed by the public were located in 278 places, including 146 devices placed in large shopping centres.
However, the research showed that only just over one in 10 nursing homes, around one in 20 train stations and a similar number of community centres and village halls had defibrillators.
The experts said their findings "would probably be similar" to elsewhere in the UK.
They said o nly between 2% and 12% of those who have a heart attack outside hospital survive but defibrillators could at least double the chance of survival.
The experts stressed the devices are "safe and effective when used by members of the public even with minimal or no first aid training".
They added: "The poor survival rates in (out of hospital) cardiac arrest are in part related to delays in defibrillation. More defibrillators are required in public areas and more education is needed to give bystanders the confidence to use (one) when it is available."
In an accompanying editorial, Drs Mickey Eisenberg and Tom Rea, of King County Emergency Medical Services in Seattle in the US, said defibrillators should be considered a public safety device similar to smoke alarms and fire extinguishers.
"We can be thankful for the handful who are saved with early defibrillation, but we should be troubled by the many who are denied the benefit," they said.
Christopher Allen, senior cardiac nurse at the British Heart Foundation, said: "It can be frightening and confusing when someone collapses in front of you and has a cardiac arrest, but some people will not survive without the aid of a defibrillator.
"These machines are fully automated. When you open the lid a recorded message will instruct you how to use it. All you need to do is attach the pads and press a button. Sensors in the defibrillator will detect if a shock should be delivered, so people should feel confident about stepping in.
"In some parts of the world, survival rates from cardiac arrest are around 50%. If we want more people in the UK to survive we need to improve public knowledge of CPR and make defibrillators more widely available. That's why we're lobbying for a legal requirement for defibs to be installed in busy public areas.
"If a defibrillator isn't available, after dialling 999, you should push hard and fast - two times per second - in the centre of the chest, until the emergency services arrive."