Raoul Moat's heart was still beating when he arrived at hospital after shooting himself in the head, his inquest has heard.
A paramedic described seeing the gunman take a deep breath as he lay on the ground fatally injured in Rothbury, Northumberland, last July.
He was part of an emergency response team that battled to save the 37-year-old former doorman's life.
North East Ambulance Service hazardous area response team manager Simon Swallow said the gunman had a "strong, normal" heart rhythm but was not breathing during the 35-minute dash from Rothbury to Newcastle General Hospital's accident and emergency department.
He rushed from a police armed response vehicle to Moat's stricken body after hearing "a loud bang", the jury at Newcastle Crown Court heard.
Moat had lifted his sawn-off shotgun to his right temple and pulled the trigger. Mr Swallow said he had to ask a policeman where Moat had been shot. He said: "I know it sounds quite bizarre bearing in mind we are talking about a shotgun wound to the head but he had his hood up and a cap on. The policeman gestured with his arm and I looked very briefly. It was quite a strange atmosphere."
Asked by Newcastle Coroner David Mitford whether Moat showed any sign of life, Mr Swallow said: "Not initially but soon after, and I'm talking seconds, he actually drew a large breath. After that large single breath he did not draw another."
The former doorman was connected to intravenous drips and fitted with a breathing mask and electrocardiogram heart monitor. Mr Swallow said: "His heart was fine, in a normal sinus rhythm. He had a really strong output. His heart was normal. But he was not breathing; he was in respiratory arrest. It was a difficult situation to be in, knowing the extent of the injury."
He continued to treat Moat "all the way to the hospital" where an accident and emergency team including a neurosurgeon was waiting. Cross-examining, John Beggs asked: "Despite your best efforts, that shotgun injury was absolutely non-survivable; there is absolutely no way he could have survived it?" Mr Swallow replied: "That is fair to say."
The 37-year-old was pronounced dead on arrival at Newcastle General Hospital in July last year. The inquest at Newcastle Crown Court continues.
