Dad-of-two Alan Galloway, 46, fell ill at home after his speech began to slur and he collapsed.
Wife Karen, 42, dialed 999 and was given instructions by a call handler who told her how to keep Alan breathing until paramedics arrived.
The couple's sons, Cameron, 19, and Nathan, 17, were at home at Cambuslang, South Lanarkshire, when their dad suffered a tonic-clonic seizure.
Alan was not breathing and was unresponsive, and was taken to Hairmyres Hospital, South Lanarkshire, for treatment.
His wife thanked medics including call handler Sarah Mark who helped her to save his life.
Karen said: "Sarah saved my husband's life and because of that our sons still have their dad and I can't thank her enough.
"She was amazing - she was not only my husband's guardian angel that night but our family's."
She described how the family's day had been unremarkable.
Karen said: "He said he felt fine and he looked fine.
"He then went into kitchen but as our son Cameron was at the top of the stairs he heard a noise, he ran down then he called for me.
"By the time I got downstairs, he had stopped physically seizing but his mouth was clamped shut and his limbs and hands ridged.
"I asked him if he was OK and he made a noise and squeezed my hand.
"He then closed his eyes and went into what we thought was a sleep.
"I put him in the recovery position."
She called for an ambulance and Sarah Marks, a call handler, answered.
Karen added: "Sarah was fantastic.
"She then asked me to let her know every time Alan took a breath in and out. I knew his breathing wasn't right, it was getting longer between breaths and longer exhaling.
"She told me an ambulance was on its way.”
Karen was asked by Sarah to start giving instructions for CPR over the phone.
She added: "I was petrified because I knew what was coming next.
"She asked me to get him on to his back and tilt his head back to open airway.
"I knew she was going to say he needs help and needs CPR but never in a million years did I think it would be me doing it.
"Sarah said 'I need you to listen to me as you need to start CPR, count with me 1,2,3,4.' "Our two sons where hysterical at this point and I had to say to our oldest son Cameron 'I need you to stay calm, go see your brother.
"I need to be able to hear the instructions from Sarah loud and clear to help your dad'."
Karen started to give CPR and prayed as well.
She added: "With each chest compression, I kept saying to myself 'please God don't take him from me, not yet', and by the grace of God he started breathing normally and came round.
"I have never been so relieved to see an ambulance crew in all my life.
"Thank you just doesn't seem enough.
"To all the ambulance crew and Sarah a million thank yous.”