Mr Ward said that once his neighbour hit the ground his first aid training came back to him.
Mr Ward is maintenance team leader for Fonterra Te Awamutu and undertakes training as part of his employment.
He immediately began CPR, and kept going for 40 minutes - much longer than a human can usually take it.
He stopped only when an ambulance arrived and revived Mr Macnicol with a defibrillator.
Mr Macnicol was assessed for brain damage and was put into an induced coma and brought around slowly to give him time to recover.
He spent two-and-a-half weeks in hospital.
He said doctors told him he had a 1 per cent chance of surviving the attack. He was also told even if someone knew how to do CPR, a male can usually sustain it only for 15 minutes, maybe 20.
He said it was incredible Mr Ward could keep going for twice as long.
But Mr Ward said it felt like only 10 minutes and all he was concerned about was not letting his neighbour die.
He broke five of Mr Macnicol's ribs in the process, but Mr Macnicol said that was nothing.
"I feel bloody good now, and bloody lucky," he said.
"I may have a damaged heart, but it must be strong to get though this."
He told the heart attack was waiting to happen but the act of shearing the sheep wasn't the cause.
But Mr Macnicol doesn't want to take any chances and said he was selling his handpiece. "I'm not ready to die, I'm too busy and have too many things left to do."
Mr Ward finished the last sheep himself and said he didn't want his neighbour helping out again.
"He's only allowed to come to our place now to pick lemons or have a beer on the deck."
