An additional 389 public access defibrillators were registered with Yorkshire Ambulance Service over the last 12 months - taking the number in the county to 883.
The ambulance service is working with community groups and charities to encourage the introduction of defibrillators in communities across the county.
Defibrillators deliver a high energy electric shock to the heart through the chest wall to those in cardiac arrest.
A patient’s chance of survival falls by between seven and 10 per cent with every minute that defibrillation is delayed.
Paul Stevens, Head of Community Resilience for Yorkshire Ambulance Service, said: “We are thrilled that almost 400 additional defibrillators have been registered with the ambulance service during the last financial year. This is a massive achievement because every second counts when a cardiac arrest occurs.
"With fast and effective CPR and defibrillation, the patient’s chances of survival increase significantly so the more defibrillators we have in our communities and the more people trained in CPR, the better.”
In addition to the public access defibrillators, which can be accessed in their cabinet by getting a security code from a 999 ambulance operator, there are also 2,447 at locations including GP practices, railway stations, supermarkets, offices, shopping centres and police stations.