Blaenau Gwent AM Alun Davies has revealed how he suffered a cardiac arrest while running last week.
The assembly member opened up on his blog about collapsing in Bute Park in Cardiff on Friday before being rushed into hospital on Friday night .
His partner, Cardiff North MP Anna McMorrin, has also shared how her Friday night was spent "standing outside A&E not knowing" if he was going to survive while not being permitted to see him.
In his blog, Mr Davies said: "Somewhere in park – I still don’t remember where exactly – I saw some old friends of mine and stopped to have [a] word.
"I was pleased to bump into them. It was very nearly the last thing that I ever did.
"Apparently – and I have no memory of this – I stopped and took a breath, said hello, and then collapsed. I know because of the cuts and bruises on my head and face that the collapse was total and immediate.
"It turns out that I had suffered a cardiac arrest. At that moment my heart had simply stopped beating.
"It had ceased to function. The most reliable pump that nature has ever constructed simply stopped working."
The Labour politician told how he was given CPR by his friends as a 999 operator guided another person to the nearest defibrillator.
He was taken to the University Hospital of Wales and said he believes he spent Saturday unconscious.
He said: "I was connected up to various machines and feeling in extreme discomfort.
"I know that I received and replied to some text messages. But I also now know that medical staff were forced to ask Anna to give consent on my behalf for some procedures because I was not able to give reasoned consent myself.
"I lay in bed listening to people discussing me. There must be an elocution school for cardiac surgeons and airline pilots. In his utterly calm, confident and reassuring voice the surgeon told me exactly what he was going to do to me."
In his blog, Mr Davies also took the opportunity to thank NHS staff for saving his life.
He said: "And a few days later I’m sitting here in hospital and writing these words.
"We all talk about the NHS and it may well have its faults, but at a time when it is dealing with the biggest health crisis in our lifetimes it can also save the life of an overweight middle-aged man with a vision of himself as championship middle-distance runner.
"The best way to give thanks of course is not to waste the gift that has been given. [Friends] Mike and Thoma, the paramedics and the staff in the Heath Hospital have given me the gift of life for a few more years.
"I’m feeling a profound sense of gratitude to everyone who stopped to help, friends who have texted and contacted me over the last days and to all those people who took care of me in hospital. Together they have saved my life and enabled me to write about this."
In a tweet, Anna McMorrin said: "It's been a very stressful and scary few days. Spent most of Friday night outside A&E not knowing if you were going to survive and not allowed in to see you.
"I can't thank the amazing paramedics and staff at the CCU in the Heath enough."
