He was taken to Hammersmith hospital , where doctors regulated Blair 's heart beat via electric shock in a procedure called " cardio-version " .
He was eventually taken to London 's Hammersmith hospital , where doctors regulated Blair 's heart beat via electric shock .
Adolescent specialist Dr Michael Cohen , who worked on the study , said doctors had treated eight-year-old children with anorexia - and that he had once treated a four-year-old boy .