A nine-month-old baby boy experienced 25 cardiac arrests in a single day — but against all odds, he survived.

Little Theo Fry, who is now 19 months old, is believed to have experienced an extraordinary number of cardiac emergencies within 24 hours, according to reports from British doctors.

But his heart problems began when he was just eight days old in May.

He started turning blue and then grey after appearing unusually sleepy to his mum, Fauve Syers, who called 111 as a precaution.

The NHS helpline advised that Theo should be taken immediately to Salford Royal Hospital, where a team of 40 medical professionals was waiting for him.

They discovered that he was experiencing heart failure and urgently needed surgery to survive.

Doctors managed to stabilise him, but he required open-heart surgery four days later at Alder Hey Children’s Hospital in Liverpool.

Theo was diagnosed with an interrupted aortic arch, a rare heart defect that meant his heart — which also had two holes — could not pump blood around his body properly.

Dad Steven Fry, 35, told The Mirror: “We were told if we hadn’t called 111 that night, Theo wouldn’t have woken up the next morning.”

He even experienced a cardiac arrest during the operation, as surgeons worked tirelessly to keep him stable.

“I watched the resuscitation team working on him with every chest compression, thinking, ‘Oh my God, please don’t let this be his last breath.’”

Medical teams kept him at Alder Hey for three months, during which he developed sepsis and experienced another cardiac arrest.

But after he was discharged, Theo continued to experience arrhythmia for weeks — a condition in which the heart can beat at dangerously high speeds — and he was taken back to hospital.

He was initially expected to stay for 24 hours of monitoring, but he would not return home for another six months.

After spending Christmas in intensive care and experiencing three separate cardiac emergencies, his condition became even more serious on the night of January 31.

He experienced 25 cardiac arrests in just one day.

Mum Fauve said: “It was horrific. He was having one episode after another. I knew he couldn’t take much more. Every time it happened, nurses would call the emergency response team.

“I watched the resuscitation team working on him with every chest compression, thinking, ‘Oh my God, please don’t let this be his last breath.’”

Theo was taken into surgery for ten hours, where surgeons discovered that his left ventricle was covered in scar tissue, preventing it from working properly.

But after doctors successfully completed the operation, Theo made a remarkable recovery and was back home within days.

Over the following year, Fauve and Steven also raised funds for Healing Little Hearts — a UK charity that sends surgical teams to countries with limited medical resources to perform heart operations on children who might otherwise have little access to life-saving treatment.