[1] Leeds Gen Infirm, Dept Cardiol, Great George St, Leeds LS1 3EX, W Yorkshire, England
[2] Pinderfields Gen Hosp, Dept Cardiol, Wakefield WF1 4DG, W Yorkshire, England
[3] Bradford Royal Infirm, Dept Cardiol, Bradford BD9 6RJ, W Yorkshire, England
[4] Univ Leeds, Dept Cardiol, Leeds LS2 9JT, W Yorkshire, England