1. Department of Cardiothoracic Surgery and Transplantation, Harefield Hospital, Harefield, Middlesex, UK
2. Department of Radiology, Harefield Hospital, Harefield, Middlesex, UK
3. Department of Anaesthesia and Intensive Care, Harefield Hospital, Harefield, Middlesex, UK
4. Department of Cardiothoracic Surgery, Royal Brompton Hospital, London, UK
5. Department of Cardiology, Harefield Hospital, Harefield, Middlesex, UK