Sid Sofos, who has travelled the world teaching and has worked with the likes of Lennox Lewis and Steven Seagal, thought he was going to die.

A kung fu master who was on death’s door after his weight ballooned to 27 stone due to a mystery illness has thanked the cardiologist who saved his life.

Sid Sofos, 47, from Drayton Park, Highbury, was suffering with a rare condition which stopped his heart from functioning properly, causing water retention, and he spent a year searching for a diagnosis.

Known as the “17th scroll grandmaster” in the world of martial arts, Mr Sofos spent eight months confined to his home – a far cry from his previous life as a wing chun kung fu champion who travelled the world teaching thousands of children, even working with the likes of Lennox Lewis and Steven Seagal.

When his condition worsened in April, he was taken to the Royal Free Hospital, Hampstead, where consultant cardiologist Dr Joseph Davar diagnosed him with constrictive pericarditis and he finally got the treatment he desperately needed.

Mr Sofos, who has a two-year-old son Harry, said: “I saw various doctors and they couldn’t give me a diagnosis and it just got worse and worse. By April this year I couldn’t walk, I couldn’t even move. It was unbearable, especially as I was so active before – I’ve been practising professional martial arts for over 30 years and have schools in Tottenham, Ireland and America.

“I was at such a low ebb, I thought my life was coming to an end. I thought I wasn’t going to be able to watch my son grow up. Dr Davar was like my knight in shining armour – I owe my life to him.”

This week Mr Sofos, who is now practising kung fu again, personally thanked Dr Davar and presented him with a Chinese statue inscribed with the words: “In the depths of winter you gave me an invincible summer. Thank you for saving my life.”

Mr Sofos underwent surgery at St Barts Hospital and then returned to the Royal Free where he lost 12 stone in fluid in under a month.

Dr Davar, who has only seen a handful of cases like it in his 17 years at the hospital, said: “It gives me a great sense of satisfaction to know that I’ve made such a difference to someone’s life. I’d like to thank Sid for his thoughtful gift – it’s taking pride of place in my office. I’d also like to thank all his students who have written to me – I’ve had many letters of thanks from them.”