Tests carried out at the Royal Liverpool Hospital and at the cardiothoracic unit at Broadgreen showed that the 54-year-old had a problem known as dissection of the aorta, which required 11 hours of emergency open-heart surgery.

BBC: Profile: Gerard Houllier

Dr Mark Waller, the club's doctor, said the manager's chest pain had been caused by a dissection of the descending aorta.

BBC: Gerard Houllier