[1] Western Infirm & Associated Hosp, Dept Cardiol, Div Cardiovasc & Med Sci, Glasgow G11 6NT, Lanark, Scotland
[2] Glasgow Royal Infirm, Scottish Cardiopulm Transplant Unit, Glasgow G4 0SF, Lanark, Scotland
[3] Royal Brompton Hosp, Dept Cardiol, London SW3 6LY, England