A woman whose heart stopped for six hours has made a remarkable recovery thanks to a fortunate set of circumstances and the valiant work of her doctors.

Announcing the story this week, her doctors from Vall d’Hebron hospital in Barcelona, Spain believe the case is among the longest-ever recorded cardiac arrests.

Audrey Schoeman, a 34-year-old British-born teacher who lives in Barcelona, developed severe hypothermia while hiking during a snowstorm around the Pyrenees mountains of northern Spain. After she went into cardiac arrest, it was actually the hypothermia that would save her life.

After setting off for a hike on the morning of November 3, the weather started to worsen. Schoeman cannot remember anything after that morning, although her husband Rohan notes she started to behave unusually and talk in a “strange and unconnected way.” In the early afternoon, she suddenly stopped moving and slipped into unconsciousness. 

Rohan called some friends who were nearby and they alerted the emergency services at 1:36pm local time. However, due to the harsh weather and remote location, they were unable to reach her until two hours later. By the time she was airlifted to hospital, her body temperature had plummeted to just 18ºC (64.4ºF) – normal body temperature is 37ºC (98.6ºF). 

Things went from bad to worse when her heart stopped beating. 

“It seemed that she was dead," her doctor Eduard Argudo said in a statement, "but we knew that, in the context of hypothermia, Audrey had the chance to survive." 

Fortunately, the hospital was equipped with an ECMO (extracorporeal membrane oxygenation) machine that temporarily replaces the lung or heart function. It does this by removing blood from the patient, pumping it with oxygen, and circulating it back around the body. 

She was only able to make it this far because the desperately low body temperature caused by hypothermia had effective shut down her body, preserving her organs and brain from deteriorating into further major damage. 

“Although hypothermia was about to kill Audrey, it also saved her because her body – and above all her brain – didn’t get any worse," Dr Argudo explained. "If she’d been in cardiac arrest for that long with a normal body temperature, we’d have been certifying her death. But we knew that the severe hypothermia meant that we had a shot at saving her, thanks to the ECMO.” 

Hours passed hooked up to the ECMO, her heart still technically not beating, until her body temperature gradually warmed up. At around 9.45pm, her body temperature was warm enough for doctors to kickstart her heart by administrating an electric shock using a defibrillator.  

“And it happened just like that: her heart started beaten autonomously again," said Dr Argudo. 

Understandably, Audrey was still in a desperately ill state. Many of her major organs were struggling from the previous hours of turmoil and lack of oxygen. Yet, after 12 days of continued treatment and care, she was eventually released from the hospital with just a few minor complaints, such as sensitivity in her hands due to the hypothermia. 

“It’s like a miracle except that it’s all because of the doctors,” she told Catalan broadcaster TV3, reports Reuters. 

If you’re curious, the longest ever recorded cardiac arrest that resulted in a patient's complete return to normal was 6 hours 52 minutes, and also involved a young woman who suffered hypothermia after hiking in extremely cold conditions. The lowest body temperature ever recorded that someone has recovered from is 13.7°C (56.7°F), when Anna Bågenholm, a Swedish radiologist, survived a skiing accident in 1999 that left her trapped under ice in freezing water for 80 minutes.