[1] Univ Hull, Castle Hill Hosp, Dept Cardiol, Kingston Upon Hull HU16 5JQ, Yorks, England
[2] Univ Birmingham, Dept Primary Care & Gen Practice, Birmingham B15 2TT, W Midlands, England
[3] Leeds Gen Infirm, Inst Cardiovasc Res, Leeds LS1 3EX, W Yorkshire, England
[4] Queen Elizabeth Hosp, Dept Cardiothorac Surg, Birmingham B15 2TH, W Midlands, England
[5] Wolverhampton Hosp NHS Trust, New Cross Hosp, Wolverhampton WV10 0QP, W Midlands, England
[6] Royal Brompton Hosp, Cardiovasc Magnet Resonance Unit, London SW3 6NP, England
[7] Northwick Pk Hosp & Clin Res Ctr, Cardiac Res Dept, Harrow HA1 3UJ, Middx, England