Around 13 people a day die from a sudden heart attack in Ireland.
The Irish Heart Foundation is holding its annual fundraising campaign today.
Volunteers around the country are selling Happy Heart Pins to raise money for CPR training.
The charity's Ruth Guy says CPR can mean the difference between life and death for someone.
"If you have somebody onsite who is trained in CPR, they can handle resuscitation and keep an individual alive until the emergency services arrive.
"We are the biggest trainer of CPR across the country and it's a critical service.