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.
More top news
Clear, crisp & freezing cold with fresh falls of snow
A bid to hold a new inquest into the death of Stuart Lubbock - who was found dead in Michael Barrymore's swimming pool - has been blocked.
Scientists exploring the huge underwater labyrinth in Mexico have found remains suggesting it was once used by the Mayans.