'No kissing': Your CPR stories
The British Heart Foundation is urging people to forget "mouth-to-mouth" and to concentrate on chest compressions when performing CPR.
New polling by the BHF suggests many feel worried about the idea of giving the "kiss of life".
BBC News website readers have been sharing their experiences of performing CPR.
John Osborne: 'A pretty cool ending to a first date'
I'd been out for a lovely evening on a first date when a girl who I now know was called Theresa collapsed next to my car.
While her date was staring down at her inanimate body on the pavement, my TA training just kicked in and I started performing CPR on her.
It was a busy Friday night in Covent Garden and I was shocked by the crowd that gathered, and by the time it took for an ambulance to turn up - nearly half an hour.
The girl stopped breathing a couple of times but I found the crowd more challenging than the actual CPR - you'd have thought I was busking given the number of people looking at me.
Thankfully Theresa survived. She was a 22-year-old blonde and my date teased me saying that was why I helped.
It was a pretty cool ending to a first date, with the woman who became my wife. Take the opportunity to get trained, you never know when it may come in handy.
Christopher Pratley: "I wish the outcome had been different"
I was once called upon to give CPR after a country walk in Kent.
My then girlfriend and I were returning to our car, when another car staggered to a halt in the road - the driver, a middle-aged man, had suffered cardiac arrest.
I had been given workplace first aid training by my employer and immediately began to attempt resuscitation using breaths and compressions, whilst my girlfriend called for an ambulance and comforted his wife.
An ambulance reached us in 15 minutes but unfortunately the gentleman had passed away. His wife, very kindly, later notified us that the post-mortem had indicated that he could not have been saved.
Practising the kiss of life on a dummy does not prepare you for the actual feel and smell of a stranger's body at such close proximity.
Despite that, and the fact that every detail of the experience remains with me to this day, I am glad I was there and able to help.
I wish the outcome had been different, but I am sure we could not have done any more. I hope I still have the courage and presence of mind to act, should I be faced with similar circumstances in the future.
I have both received CPR and given it so feel not only indebted to a stranger who saved me but proud that I saved a life. I got taught how to do CPR at school but never thought I would ever have to use it. But one day back in 2008 whilst travelling home from university on the Underground, an elderly man collapsed and without thinking I began to give him CPR until paramedics arrived. Thankfully, the man survived and I was thanked for my actions. Unfortunately, last year I collapsed in the street and stopped breathing after a seizure. A passing member of the public performed CPR - I am eternally grateful as it no doubt saved my life. Coll, Scotland, UK
As someone who has held a first aid certificate since my mid-teens I feel that the advice that is given should be tempered by reality. The reality is that if someone suffers cardiac arrest or a heart attack, then the odds are immediately stacked against their survival. So get stuck in! But if it goes pear-shaped and the casualty dies, you should not feel guilty - it's not your fault. Steve, Cardiff, UK
When studying to be a nurse back in 2006, my friend saw a young man lying on the road unconscious with a significant head injury. I started CPR whilst my friend rang an ambulance. There were four bystanders who didn't realise that he was snoring because his airway was closing up, and not because he was asleep. I am sure that my CPR technique was not perfect, however if we had not intervened this young man would have died. We never found out why he was in the middle of the road. Marie Dzirvinskis, Bristol, UK
I was at work one day and a colleague called out that someone had collapsed in the street. I rushed out of the office trying to call the emergency services whilst crossing the road. I couldn't get through and put the phone in my back pocket. Another colleague managed to get through to 999 and I was able to perform mouth-to-mouth and CPR. In the meantime the ambulance service were trying to call me on my mobile, but not wanting to stop CPR all I could hear whilst performing it was my BBC Dalek ring tone: "Exterminate, exterminate, exterminate!" Andrew Robson, Oxford, UK
Having been trained as a first aider I am familiar with the kiss of life and chest compressions. I have had to give mouth-to-mouth to a squash player who collapsed on an adjoining squash court. His heart had stopped and I managed to get it going again only for it to stop one final time. Despite all my efforts to restart his heart, he sadly passed away. Steve Stylianou, Stockport, UK
I had basic CPR training through work, and when my Dad had a heart attack I was able to do CPR with breaths. I kept going with help and advice from the ambulance service on the end of the 999 line as I couldn't remember the number of compressions to breaths. I kept going until the emergency services got there, and they took over and even did a cardio version, but sadly it was too late. I felt so empowered to have been in a position to do something and not panic. Charulata Raut, London, UK
Five years ago I resuscitated a man - Gary - who had had a cardiac arrest. He survived because he got immediate CPR (within 30 seconds of him collapsing) and thanks to the skills and equipment of the paramedics. Nick Fortune, Australia
I am a scuba diving instructor and have received some training in CPR although admittedly very basic. I had the unfortunate experience of having to perform CPR on a 20-something girl who had been found floating face down in the sea in Malaysia. After getting her out of the water two of us performed CPR - my friend doing compressions and me doing the breaths, after trying for several minutes we then took her to a nearby medical centre by boat (still trying to keep compressions and breaths going) but unfortunately shortly after she was pronounced dead. We both felt awful for a while and questioned what we could have done differently, but at least we tried. My point is nobody should be afraid of trying as you can hardly make the situation any worse. If you're lucky you may save a life. Barry Smith, Malaysia
My husband was found collapsed in his office, alone at work by a labourer on his building site. He wasn't breathing, had no heartbeat and was blue in the face. This man rang 999 and performed CPR with advice from the ambulance service for 23 minutes whilst they arrived. Whilst he spent some time on life support and months in neurology rehab for the brain injury from lack of oxygen, he has a relatively "normal" life and is at home with his family thanks to this man's willingness to have a go. Me and the four children will be eternally grateful to the man who gave him CPR and the staff that cared for him in the months that followed. Maxine Hayman, Bradford, West Yorkshire, UK
I have performed CPR on five different occasions and despite my best efforts have failed on each occasion. The paramedics who attended did say I did very well, but I still feel so incompetent and useless! I have trained and trained - maybe one day I will be able to help someone. Phil L, Australia
I had to perform CPR on my father, shortly after I gained my first aid at work certificate. I didn't hold his nose tight enough at my first attempt at mouth-to-mouth, so blew his nose! Messy. But I kept him alive until the ambulance arrived. I was exhausted by then. Chest compressions are hard work. Mouth-to-mouth is very intimate and I wouldn't want to do it on a manky stranger. Ian, Ilford, Essex