By Jane Elliott
Health reporter, BBC News
A British Heart Foundation study has shown two-thirds of people would not call for an ambulance if they feared they were having a heart attack.
Kay was only 40 when she had her heart attack
But the BHF said the delay was costing lives.
When Kay McCaw was having a heart attack, her first thought was not to cancel the viewing of a house she was hoping to buy.
She dismissed her early symptoms as indigestion and even as they grew worse she resisted dialling 999.
Her first call was to a friend who was coming with her to view the new house.
Luckily for Kay, 42, from Surrey, her friend was only minutes away and soon took charge of the situation, calling for an ambulance.
"I still wanted to go and see the house.
"But my friend, who had watched her father have a heart attack, said she was going to get help," said Kay.
"She told me to lie down and stay calm - I was still thinking it was indigestion!
"But when the ambulance crew got to my house I can remember them calling in and saying they could not move me because my condition was so unstable.
"When I got to the accident and emergency unit I can remember the monitors were going crazy.
"My chest was exposed, but I did not care and I felt much worse."
Kay, who was only 40 at the time but who smoked and was overweight, spent a week in her local hospital before being transferred to St George's Hospital in south London for tests.
They showed that Kay's attack had been caused by an artery spasm due to stress.
"I had just left my husband and was busy at work and looking to buy a house. It really was a stressful time."
But Kay, who has no family history of heart problems, said that despite being a smoker she had never considered herself at risk.
She has changed her lifestyle completely since her heart attack, changing her stressful job as a PA for a busy business to a job where she can work from home, stopping smoking, joining a gym and getting a dog that she can take for walks.
Delays are costing lives
She said: "I feel well and healthy and now I try to avoid stress.
"I just think to myself 'can it kill me?' and if not then I think it is not worth bothering about."
Kay said it was important that people listened to their bodies and took action if something appeared to be wrong - even if they felt silly.
"It is always better to dial 999 if you have chest pains as delaying might cost you your life."
She added: "Had my friend not done something then I would not have called for an ambulance.
"I do suffer from indigestion and thought that is what it was.
"But the ambulance service said they would rather people ring than delay because it could be the difference between life and death."